from:"ew via time\-nuts"

[time-nuts] GPS Control Loop

2022-04-21 Thread ew via time-nuts


25 years ago Brooks Shera developed a GPSDO that had a Frequency accuracy of 1 
E-11. A year later in  1998 he published his work in July 11998 in QST. The 
total package included circuits,   PC board and in depth analysis of every part 
of his design including his filter.. I was one of the first buying the board, 
GPS receiver and working with an other Time Nut building a couple of units. 
Using my Tracor 527E,, HP5345A and aHP5061A Cs in parallel to an Austron Loran 
C system using multiple HP 10811's in all cases observed better than 1 E-11 
frequency.  All 10811's had previously been tested to have an AV below E-12. 
Subsequent tests with Austron 1150 and Datum 1000 showed even better results. 
Over time Brooks added features but the design remained the same. His last 
effort was to make other DAC's available, but at that time his Cancer had 
spread to his brain.

Lets remember this was the time of S/A and it is safe to say GPS has improved 
by a factor of 100. DAC's compared to the Audio DAC are also improved by a 
factor 50.

Using later circuits we still use his design and Richard McCorkle did a PIC 
based on his Filter for us.

Very little else has changed. Reviewing commercial units like End Run short 
term is a function of the OCXO or Rb, long term GPS.

There was a time when Time Nuts had access to quality surplus OCXO's and Rb's 
at a 'reasonable" price, that tine is gone. Before the time I did get an OSA 
8607 I did look at a Morion OCXO, their best with an AV of 2 E-13 at 1 second. 
The would not respond to my RFQ but thanks to a Time Nut that buys from them 
regular the answer was 6000 Euro and 1 year delivery after order!
To us Shera is the Gold Standard. worth a review for any one doing their own 
GPSDO, we are presently focusing on the best GPS receiver, my problem is Ublox 
9T is not an option because at 80 I am not able to get safely on the roof. Hire 
some one is an option but liability may be a problem                            
                                                 Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Low Phase Noise 10 MHz bench signal source sought

2022-04-03 Thread ew via time-nuts

There is a lot of talk of Rb's and OCXO's  and using an OCXO for clean up. Very 
little about the clean up loop. It is key for overall performance. We are 
working on it for quite some time and are not happy with the results. On list 
off list would greatly be appreciated.                                          
            Bert Kehren  
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: HP53131 Power Supply shortened

2021-12-09 Thread ew via time-nuts

My 132 Power Module failed. Not made by HP. removed the white silicone one 
Diode was not soldered in sometimes touched, solder it in no more problems.     
                                                                                
                     Bert Kehren                                                
                                                                                
                                                                                
                                                           

In a message dated 12/8/2021 7:02:06 PM Eastern Standard Time, kb...@n1k.org 
writes: 
Hi

The PSU in the 131 is a known weak point. Usually when they die, they
take a lot of parts out in the process. The good news is that the PSU in 
the 53181 is the same as the 131 PSU. Since 181’s tend to sell for “not
much” they are a fine parts donor ….

Bob

> On Dec 8, 2021, at 5:53 PM, Marek Doršic  wrote:
> 
> Hello,
> 
>    while taking a measurement my HP53131a counter sparked and became quiet. 
>After tear down I found both 3A/240V fuses in the PSU burnt. Before pluging a 
>new set of fuses, is there a knowledge of a common problem that couses a 
>shortcircuit at the HV side?
> 
> The counter has also a spilage at the bottom side of the mainboard, but as it 
> is same as in Gerry Sweeney's youtube video (HP 53131A Teardown and Spillage 
> Clean-Up ) and his counter still 
> works I assume it is not related. Is it a good practice to get it cleaned?
> 
>  .marek
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
> email to time-nuts-le...@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] HP 5065A on ebay

2021-11-28 Thread ew via time-nuts

Two HP 5065A on ebay in Germany                        Bert Kehren
 https://www.ebay.com/itm/353785283417?hash=item525f3f0359:g:~GkAAOSwNgZhoODS 
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Fwd: Re: Project Great

2021-11-28 Thread ew via time-nuts




If you are in Germany the Zugspitze at 2962 meter and Garmisch 700 meter would 
be perfect. Good amenities at both locations.                                   
                                                                                
                                                                                
      Bert Kehren                                                               
                                                                                
                                                                                
                                                                   

In a message dated 11/27/2021 5:12:19 PM Eastern Standard Time, 
j...@luxfamily.com writes: 
On 11/27/21 12:37 PM, Thomas Valerio wrote:
> I think that Tom's GREAT adventure is kind of what sealed the deal making
> me a time-nut or at least a time-nuts lurker, a lot of this stuff is still
> little over my head, but I keep reading.
>
> If anyone is inclined and has the clocks and the kids ( I don't have
> either ), there is always Mount Evans and Pikes Peak, although you may
> have to leave the clocks behind overnight.  Mount Evans is still on my
> bucket list but without clocks and two or three days of time to monitor
> them, I don't think I will be doing the Mount Evans edition of GREAT.  For
> anyone that is flush enough to afford or can beg, borrow or steal access
> to a Microsemi chip scale atomic clock, I think a Mount Evans edition
> would be an awesome addition to Tom's original work.
>
>    Thomas Valerio
>
I don't think a CSAC would be good enough.

Tom's experiment was 22 ns out of 42 hours or about 1.45E-13. That's 
quite a bit smaller than a CSAC adev over that period.

There's a variety of roads that go to ~12,000 ft in Colorado, about 
~10,000 in CA (Tioga Pass isn't closed yet), so you can get about 3x 
change, but still you're talking <1E-12.

Mammoth Mtn has a gondola to the top, but it's only 11,000. There may be 
a ski resort in CO that's higher.


>> For newcomers to time-nuts, Andy is asking about my DIY gravitational
>> time dilation experiment(s).
>>
>>  > What am I missing?
>>
>> It looks like you used the wrong value (or wrong units) for "h".
>>
>> The summit of Mt Rainier is 14411 ft (4400 m), but the highest point on
>> Mt Rainier that is accessible by road is the Paradise visitors center at
>> 5400 ft. Our house is at 1000 ft elevation so the net difference in
>> elevation of the clocks was 4400 ft (1340 m).
>>
>> The clock(s) on the mountain ran fast by gh/cÂ² = 9.8 Ã— 1340 / (3e8)Â² =
>> 1.5e-13. Fast clocks gain time. We stayed for about 42 hours so the net
>> time dilation was 42Ã—3600 Ã— gh/cÂ² = 22 ns.
>>
>> 
>>
>> For more information see the Project G.R.E.A.T. 2005 page:
>>
>> http://leapsecond.com/great2005/
>>
>> Better yet, these two recent talks from 2018 and 2020 cover all 3 GREAT
>> experiments:
>>
>> 
>>
>> 
>>
>> Lots of time nutty photos in both of those!
>>
>> /tvb
>>
>>
>> On 11/27/2021 7:33 AM, Andy Talbot wrote:
>>> Just been reading your adventures with 3 Cs clocks, a mountain and 3
>>> kids,
>>> but I can't make the estimate of time dilation work out.
>>> You measured ~ 23ns and say it agrees with calculation
>>>
>>> The equation quoted in a related reference, for "low elevations" is
>>> g.h/cÂ²
>>> which if you plug in g = 9.81 m/sÂ²  and h = 4300m for Mt Rainer gives
>>> an
>>> expected value of 4.7 * 10^-16.
>>> Over 2 days, 2 * 86400s, that would be 81 ns in total, four times your
>>> value
>>>
>>> What am I missing?
>>>
>>> Was just speculating what Ben Nevis at a mere 1340m height might offer
>>>
>>> Andy
>>> www.g4jnt.com
>>> ___
>>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
>>> send an email to time-nuts-le...@lists.febo.com
>>> To unsubscribe, go to and follow the instructions there.
>> ___
>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send
>> an email to time-nuts-le...@lists.febo.com
>> To unsubscribe, go to and follow the instructions there.
>>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
> email to time-nuts-le...@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow

[time-nuts] FS740

2021-11-18 Thread ew via time-nuts

I see the SRS  FS 740  and Morion Rb's and super low Av OCXO's in al my 
Microwave publications. That seems the market the are after.                    
                                                                             
Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: Isotemp OCXO question

2021-08-21 Thread ew via time-nuts

I remember in the early 90's I used a HP receiver and a Tracor M 100 with no 
problem in Miami. Junghans came to Miami to test their clocks and watches using 
a R handheld device for accurate signal evaluation. They had determined that 
Miami was the most distance from the 60 KHz transmitter in the USA.             
                                                                                
                Bert Kehren                                                     
                                                                                
                                                                                
                                              In a message dated 8/21/2021 
2:11:22 PM Eastern Standard Time, kb...@n1k.org writes: 
Hi

The WWVB transmitters are military surplus. I suspect they got them at a very
low cost to NIST. The proposal they kept floating was to set up a second LF
time signal for the east coast. That way they could do better coverage over
the entire county without going to higher power. My guess is the same 
surplus transmitters would have been dropped into someplace in New York.
It would also let them go to a frequency that was not as heavily impacted by
MSF.

Nobody ever really got behind the idea. It came up again and again. It just
never got any traction. Finally they went with this phase mod stuff. 

Bob

> On Aug 21, 2021, at 1:45 PM, Robert DiRosario  wrote:
> 
> This will just be a backup clock in my amateur radio station.  I already have 
> a Truetime XL-DC and a XL-AK, both have GPS receivers that give IRIG-B and 
> 1PPS outputs, and drive a couple of IRIG-B clocks.  I would guess the GPS 
> time signal will be more accurate and precise then WWVB, and both will be 
> more accurate and precise then my Heathkit Most Accurate Clock, which uses 
> WWV.
> 
> To the human eye, as long as the seconds match on all sources, I'm happy.  On 
> the other hand, for my GPS-NTP box and especially for my GPS-DO frequency 
> standards, I want a lot better then 1 Hz.
> 
> I really wish NIST didn't add the BPSK modulation to WWVB. Increasing the 
> transmitter power would have been a lot better, but I'm sure that would have 
> cost a lot more then just changing the modulation.
> 
> Robert
> 
> 
> 
> On 08/19/2021 09:19 PM, Bob kb8tq wrote:
>> Hi
>> 
>> The issue you run into is that the fancy devices tried to derive information 
>> from
>> the phase of the WWVB signal. With an “AM only” receiver accuracy in the 10’s
>> (or 100’s … yikes ….) of ms was pretty common. With a phase oriented 
>> approach,
>> you could get into the 100’s of us. Indeed there is a lot of fine print 
>> involved with
>> any WWVB claims.
>> 
>> The change over did not impact the typical WWVB watch or an AM based 
>> receiver.
>> It very much messed up any of the fancy timing stuff.
>> 
>> Bob
>> 
>>> On Aug 19, 2021, at 9:09 PM, Robert DiRosario  wrote:
>>> 
>>> I have a MAS6180C AM receiver chip, on a board with a few other parts to 
>>> complete the receiver.  I did not make the board, it came from
>>> Universal-Solder Electronics in Canada.  The date on the chip datasheet is 
>>> 2014 and on the receiver board 2016, so after NIST messed up WWVB in 2012.
>>> 
>>> Robert
>>> 
>>> 
>>> On 08/19/2021 07:23 PM, Bob kb8tq wrote:
 Hi
 
 It’s a good bet that whatever the spec on that Isotemp OCXO, it’s way 
 better in terms
 of temperature and aging then the DS3231. Is it still on frequency 
 (however many years
 later …..) who knows ….
 
 Many of the “time oriented” WWVB devices stopped working when they put in 
 the new
 modulation scheme. It’s a pretty good bet that this applies to the device 
 you have.
 
 Bob
 
> On Aug 19, 2021, at 6:55 PM, Robert DiRosario  wrote:
> 
> I got a  Trak Systems "Time Code Translator" from ebay.  It's a 1U box 
> with large LEDs for DOY and H/M/S that translates IRIG-A to NASA-36 time 
> code.  I plan on using the case for my WWVB clock.
> 
> Unexpectedly it has an Isotemp OCXO in it, model OCXO59-11-2, frequency 
> marked as 1.000 MHz  The Isotemp website is more or less dead, it has no 
> information on it.  Does anyone have any information on this model, like 
> how accurate it is?  It has only three wires, which I assume are power, 
> ground and output, with no EFC input.
> 
> One thing that I'm sill note sure about is what to do when the receiver 
> is not receiving WWVB.  I was thinking of using something like the DS3231 
> RTC module.  If this OCXO is better, I may use it.
> 
> Thanks
> 
> Robert
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send 
> an email to time-nuts-le...@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
 ___
 time-nuts mailing

[time-nuts] NIST trivia

2021-07-28 Thread ew via time-nuts

As time nuts we all know about NIST Time and Frequency work. NIST is involved 
in the investigation of what happened in the tragic collapse of a High Rise in 
Miami Surf Side.                                                                
                  Bert Kehren

___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: Tbolt

2021-07-22 Thread ew via time-nuts

If some one has a bad one how about opening it and take some pictures. Would be 
very informative.                                                               
          Bert Kehren                                                           
                                                                                
                                                                                
                                                            In a message dated 
7/22/2021 9:59:11 AM Eastern Standard Time, time-nuts@lists.febo.com writes: 
Attached is a plot of EFC versus Frequency of a Vectron pulled from a Tbolt. 
EFC is + and -.   I suspect that the units are shipped with the EFC set at 0 
Volt. Notice 0 Volt   Again I suspect the extra pin is  there for that purpose. 
Bob could tell us but may not want to comment to stay out of trouble.           
                                                                    Bert Kehren 
                                                                                
                                                                                
                                                                                
                                                                                
                   In a message dated 7/22/2021 5:01:10 AM Eastern Standard 
Time, time-nuts@lists.febo.com writes: 
On 22/07/2021 08:30, time-nuts-requ...@lists.febo.com wrote:> Message: 1> One 
more comment on the Vectron OCXO. My Tbolt shows a tuning voltage of +0.4 Volt 
and has 3.6 Hz per Volt. Assuming the OCXO was sold to Trimble with 0 V and my 
unit has at least 12 years on it (4380 days) aging is 3.29 E-11 per day. Not 
bad for an  OCXO.                                                               
                                                                   Bert Kehren 
 Hi. 
According to Lady Heather, My T'bolt sits with it's DAC at about 0.2V   I 
always wonder about that. From the above comment, is the DAC output (and VCXO 
input I guess) bipolar, as in can range +- some amount from 0V? I've not seen 
any schematics for them, so in honesty haven't a clue what it's likely range 
is, good bad or indifferent. I did email TVB direct about the possibility of 
sourcing another one or two of them, but as he said (and I guessed) he was 
swamped with responses. I use mine mainly as a frequency reference, powered on 
24/7 Regards to All. Dave G8KBV (In the UK as far as I can tell.)  -- Created 
on and sent from a Unix like PC running and using free and open source 
software: ___time-nuts mailing list 
-- time-nuts@lists.febo.com -- To unsubscribe send an email to 
time-nuts-le...@lists.febo.comTo unsubscribe, go to and follow the instructions 
there.___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: Tbolt

2021-07-22 Thread ew via time-nuts

Attached is a plot of EFC versus Frequency of a Vectron pulled from a Tbolt. 
EFC is + and -.   I suspect that the units are shipped with the EFC set at 0 
Volt. Notice 0 Volt   Again I suspect the extra pin is  there for that purpose. 
Bob could tell us but may not want to comment to stay out of trouble.           
                                                                    Bert Kehren 
                                                                                
                                                                                
                                                                                
                                                                                
                   In a message dated 7/22/2021 5:01:10 AM Eastern Standard 
Time, time-nuts@lists.febo.com writes: 
On 22/07/2021 08:30, time-nuts-requ...@lists.febo.com wrote:> Message: 1> One 
more comment on the Vectron OCXO. My Tbolt shows a tuning voltage of +0.4 Volt 
and has 3.6 Hz per Volt. Assuming the OCXO was sold to Trimble with 0 V and my 
unit has at least 12 years on it (4380 days) aging is 3.29 E-11 per day. Not 
bad for an  OCXO.                                                               
                                                                   Bert Kehren 
 Hi. 
According to Lady Heather, My T'bolt sits with it's DAC at about 0.2V   I 
always wonder about that. From the above comment, is the DAC output (and VCXO 
input I guess) bipolar, as in can range +- some amount from 0V? I've not seen 
any schematics for them, so in honesty haven't a clue what it's likely range 
is, good bad or indifferent. I did email TVB direct about the possibility of 
sourcing another one or two of them, but as he said (and I guessed) he was 
swamped with responses. I use mine mainly as a frequency reference, powered on 
24/7 Regards to All. Dave G8KBV (In the UK as far as I can tell.)  -- Created 
on and sent from a Unix like PC running and using free and open source 
software: ___time-nuts mailing list 
-- time-nuts@lists.febo.com -- To unsubscribe send an email to 
time-nuts-le...@lists.febo.comTo unsubscribe, go to and follow the instructions 
there.


EFC Tbolt Oscillator.pdf
Description: Adobe PDF document
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Tbolt

2021-07-21 Thread ew via time-nuts

One more comment on the Vectron OCXO. My Tbolt shows a tuning voltage of +0.4 
Volt and has 3.6 Hz per Volt. Assuming the OCXO was sold to Trimble with 0 V 
and my unit has at least 12 years on it (4380 days) aging is 3.29 E-11 per day. 
Not bad for an  OCXO.                                                           
                                                                       Bert 
Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] OSA 8600 for sale

2021-06-04 Thread ew via time-nuts

Have to go to page 2 half way down  direct ling will not give you any info

___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] OSA 8600 for sale

2021-06-04 Thread ew via time-nuts

There is an OSA 8600 in France for sale. Euro 1800. I bought my 8607 from the 
seller. Most likely never used came from an Army program like mine.             
                                                                         Bert 
Kehren

  https://www.ebay.fr/str/denis2214-cazmat?_trksid=p2047675.l2563  
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: Sparkfun lists SA.35m

2021-04-03 Thread ew via time-nuts

A couple of years back, we started to explore using Laser Diode with a FRK. 
Started by looking at shorter time constant for the loop and found that 0.055 
seconds gave best AV. Longer time constant for Laser control. Also using 
external reference for tuning. Using HP 70 000 Optical Plug in to characterize 
Lasers. Decided we did not need it, having to many FRK / M100 with good lamps , 
age, to many projects and most likely no interest by time-nuts even though 
there  are quite a few dead units out there. I am convinced a team effort not 
only talk but hardware would make it possible. With laser it would not be 
needed but a Filter with good lamp and short time constant is still on the 
list. Have a unit disassembled, but my left eye mecular hole is a problem. Did 
some soldering today, 30 minutes, that should have taken 1 minute.              
         Bert KehrenIn a message dated 4/3/2021 11:09:02 AM Eastern 
Standard Time, mag...@rubidium.se writes: 
Hi,

What you do is that you servo the semicondoctor laser to the transition,
as you do that with sufficiently narrow laser you can utilize the CBT
mode operation which has additional benefit rather than just replacing
the rubidium lamp with a semiconductor laser. Getting a laser in 780 nm
range isn't all that hard in itself, I have a bag of those lying around
for experimentation, not that they are good enough for this, but well,
it would be fun.

Cheers,
Magnus

On 2021-04-03 16:51, Dana Whitlow wrote:
> I knew about the use of the VCSEL, but I'd bet a good dinner that it's not a
> Rubidium laser!  Last I heard, none of the elements in that corner of the
> periodic table were semiconductors, and it's hard to imagine a vapor-based
> VCSEL.
>
> Dana
>
>
> On Sat, Apr 3, 2021 at 7:31 AM Lux, Jim  wrote:
>
>> On 4/3/21 4:22 AM, Dana Whitlow wrote:
>>> "rubidium laser" ???
>>>
>>> Dana
>> I don't know about the MAC, but the CSAC uses a VCSEL to shine through
>> the gas cell.
>>
>> The MAC is a pretty big thing compared to the CSAC - it's in the usual
>> 2x2" package and draws 5-8W (after warmup)
>>
>>> On Sat, Apr 3, 2021 at 2:15 AM Poul-Henning Kamp 
>> wrote:
 I know it's not a particular outstanding atomic clock, but I was still
 surprised to see that Sparkfun lists the SA.35m for $1995...

          https://www.sparkfun.com/products/14830

 Not in stock though...

 --
 Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
 p...@freebsd.org        | TCP/IP since RFC 956
 FreeBSD committer      | BSD since 4.3-tahoe
 Never attribute to malice what can adequately be explained by
>> incompetence.
 ___
 time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
>> send
 an email to time-nuts-le...@lists.febo.com
 To unsubscribe, go to and follow the instructions there.

>>> ___
>>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe
>> send an email to time-nuts-le...@lists.febo.com
>>> To unsubscribe, go to and follow the instructions there.
>>>
>> ___
>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send
>> an email to time-nuts-le...@lists.febo.com
>> To unsubscribe, go to and follow the instructions there.
>>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
> email to time-nuts-le...@lists.febo.com
> To unsubscribe, go to and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: The Collapse of Puerto Rico’s Iconic Telescope [April 5th, 2021 New Yorker]

2021-03-31 Thread ew via time-nuts

During my days at UTC I was among other things responsible for our Industrial 
Laser Group. We sold some 50 KW CW CO2 lasers! We had the only aero dynamic 
window that allowed  a vacuum on one side. When not in use you put a pencil 
through it. Patented.                                                           
Bert Kehren In a message dated 3/31/2021 3:17:21 PM Eastern Standard Time, 
rich...@karlquist.com writes: 

On 3/31/2021 11:57 AM, Lux, Jim wrote:

> 
> In some ways it's like high power laser labs. It's not the direct beam 
> you worry about - nobody is going to put their hand in the beam path. 
> It's the stray reflection when something gets bumped and falls across 
> the optical bench and reflects a stray beam at 0.01% power into your eyes.

I did consulting at Coherent Laser Group working on CO2 lasers.
In that lab, actually, many people had the misfortune of accidentally
putting their hand or arm in the invisible beam.  You could see the
scars on their arms.  There were also accidents where the laser
burned the ceiling, etc.  Very scary place to work; fortunately,
I never got injured.  They made lasers up to 1kW optical power out.

Rick N6RK
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

[time-nuts] Re: The Collapse of Puerto Rico’s Iconic Telescope [April 5th, 2021 New Yorker]

2021-03-30 Thread ew via time-nuts

GOOD Morning Tom                                                                
                                                                                
       Thank you for the super information Read it over and over. To me no joy, 
sadness for Astronomy, Science, Puerto Rico and the US. China is now the leader 
with a 500 meter unit! Did follow it since the seventies because of the low 
noise receivers.  Remember the 417 Triodes? I had some for Ham use.             
                                                      Any body knows what 
happened to its Maser?                                                          
                                                   Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an 
email to time-nuts-le...@lists.febo.com
To unsubscribe, go to and follow the instructions there.

Re: [time-nuts] An Other Ublox 8

2021-01-27 Thread ew via time-nuts

One more comment thank you Juerg for all the data analysis.                     
                Bert Kehren In a message dated 1/27/2021 7:33:09 AM Eastern 
Standard Time, time-nuts@lists.febo.com writes: 
Over the last couple of years I have looked at the LEA M8F, it is a GPSDO with 
1 pps.  not needing Saw Tooth correction. How ever its frequency output is not 
time-nut friendly. 10 MHz is only 5 E-9. An ebay post showed an 8F board with 
intriguing 24 MHz data. Juerg did some tests with an SI 5351 at 24 MHz. Spec is 
25 to 27 MHz but his tests at 24 MHz shows 10 MHz at 1 E-12.  So I bought some, 
one on the way to Switzerland. Also made some of our heavies aware of our work. 
The seller initially was not going to make more boards but changed his mind. I 
suspect the parts a pulls and he has to make boards to make sure the F8's work. 
My goal is to use it for aging tests always use 24 to 48 hour average testing. 
See my attached results exceed my expectations. 2.39 E-13 mean! Will update 
once Juerg has his unit and uses a SI 5131 to generate 10 MHz.  I can use the 
24 MHz it is a true representation of the GPS signal. Can also use other GNS 
signals. Leave that up to others.                                               
                          Bert 
Kehren___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Ebay Huawei Ublox M8T Modules Warning

2021-01-11 Thread ew via time-nuts

In the past removed more than 10  5T's with no problems using a Propane Torch, 
tapping the board and the devices did slide off. No problem.                 
Noticed Bluegirls changing her listing based on Nigel's false information. For 
the record pin 18 of the LEA devices is a very nice feature and can feed power 
to an active antenna. It is a coil coupling to the RF line and according to 
spec up to 6 V can be applied. Short protection should be included to protect 
the coil. This allows user to feed an active antenna or when using a spliter no 
power feed to the unit saving a capacitor that I always include on telecom 
devices.                                                                       
Bert Kehren                                                                     
                                                                                
                                                                                
                                                                                
          In a message dated 1/11/2021 10:15:10 AM Eastern Standard Time, 
paulsw...@gmail.com writes: 
With respect to the cut boards they are about 5 layers and some of the
layers are shorted by the cut. Perhaps sanding them down would allow the
boards to be used directly. My luck at popping the module off the board has
not been very successful so far.
Regards
Paul

On Sun, Jan 10, 2021 at 10:03 PM Bob kb8tq  wrote:

> Hi
>
> There appear to be a lot of the cut off boards. The assemblies may well be
> usable “as is”. It’s too bad there aren’t more of them. At the price, they
> are
> (used to be) an attractive alternative.
>
> Bob
>
> > On Jan 10, 2021, at 8:41 PM, Didier Juges  wrote:
> >
> > ebay seller Queen's Land sent me this picture of the back of the cut off
> > board. Apparently they still have a bunch.
> > https://www.ebay.com/usr/queen*s_land?ul_noapp=true
> >
> > Didier KO4BB
> >
> > On Sun, Jan 10, 2021 at 3:47 PM Bob kb8tq  wrote:
> >
> >> HI
> >>
> >> Looking a bit more closely at the remains of the “chopped up” boards
> with
> >> the M8T’s on them …
> >> This board is *not* the source of those devices. What’s left of the
> >> marking on those boards
> >> does not line up with what’s on these (now sold out) boards.
> >>
> >> There seems to be at least one switching regulator on this board, a CPU
> >> (with JTAG programming
> >> connector ??),  and a fairly elaborate antenna bias / protection
> circuit.
> >> No idea what might be on the
> >> back of the board.
> >>
> >> With any luck, they will get more of these in stock.
> >>
> >> Bob
> >>
> >>> On Jan 9, 2021, at 10:20 PM, Bob kb8tq  wrote:
> >>>
> >>> Hi
> >>>
> >>> Just for the sake of listing all the variations:
> >>>
> >>>
> >>
> https://www.ebay.com/itm/ON-SALE-U-BLOX-ublox-LEA-M8T-0-10-HUAWEI-GPS-Timing-Module-Board/333778776570?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
> >> <
> >>
> https://www.ebay.com/itm/ON-SALE-U-BLOX-ublox-LEA-M8T-0-10-HUAWEI-GPS-Timing-Module-Board/333778776570?ssPageName=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
> >>>
> >>>
> >>> Is the M8T on what I would *guess* is the original board. Simply from
> >> looking at the picture I think
> >>> you can guess pretty well what’s what on the board.
> >>>
> >>> Hint: If you buy quite a few …. errr … 10 … there s a pretty good
> chance
> >> that something more than
> >>> 20% might get knocked off the price …. I bought a pretty large pile of
> >> stuff so it’s not clear if that
> >>> had some impact on what offers got accepted …..
> >>>
> >>> If that’s not your favorite RF connector on the board, there are SMA’s
> >> that likely fit in the same footprint.
> >>>
> >>> Bob
> >>>
>  On Jan 9, 2021, at 6:41 PM, Nigel gm8pzr via time-nuts <
> >> time-nuts@lists.febo.com > wrote:
> 
>  H
> 
> 
> 
>  was kinda thinking that might be the case, perhaps time to hope they
> >> weren't tested after all!
> 
> 
> 
>  Late here, will check tomorrow
> 
> 
> 
>  Nigel GM8PZR
> 
> 
> 
>  Hi
> 
>  The “normal chips” that should be inside the module all have something
> >> like a 3.6V max supply rating on them.
> 
>  I would guess that 5V will melt a goodly number of them.
> 
>  Bob
> 
>  ___
>  time-nuts mailing list -- time-nuts@lists.febo.com  >> time-nuts@lists.febo.com>
>  To unsubscribe, go to
> >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com <
> >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com>
>  and follow the instructions there.
> >>>
> >>
> >> ___
> >> time-nuts mailing list -- time-nuts@lists.febo.com
> >> To unsubscribe, go to
> >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> >> and follow the instructions there.
> >>
> >

Re: [time-nuts] Ebay Huawei Ublox M8T Modules Warning

2021-01-10 Thread ew via time-nuts

We use the board but my boards are presently in Connecticut so I can not check. 
Pin 18 of the Ublox is used to feed power to an active antenna that is why the 
Rf pin does not have a capacitor. I have fed 5V in to pin 18 on ny Saw Tooth 
boards.  Some one check if pin 8 in question is connected to pin 18, may have a 
resistor in series to prevent to much current. May also measure against the 
center pin of the SMA  Hardwarre  manual limits the Voltage to 6V.              

                                       Bert Kehren                              

              In a message dated 1/10/2021 6:02:50 AM Eastern Standard Time, 
time-n...@welwarsky.de writes: 
On Samstag, 9. Januar 2021 23:38:35 CET Nigel gm8pzr via time-nuts wrote:
> I've dealt with this seller before, always been very happy with the results,
> and agreed a price on three such modules which arrived just before
> Christmas, for reference this particular Ebay ID was 333619130232, and
> finally found time to start checking them today. The modules themselves
> look very nice, but one of the auction photos is a connection diagram that
> shows Pin 2 of the 8 pin interface connector as "Power In 5V DC", and on
> this PCB that pin connects directly to the pin 6 Vcc input on the Ublox
> module, which has an absolute maximum rating of 3.6V ...whoops! This is
> not intended in any way to be a criticism of this seller, who I am more
> than happy to recommend, nor indeed of any other seller, but this is a
> generic diagram that several sellers are using for various Huawei/Ublox
> modules, some of which may have an onboard 3.3V regulator, as presumably
> did the one this diagram originally referenced, but some of which may not.

On a cursory look at the PCB, there are more odd details about it. The antenna 
circuitry and especially the bias-t looks wrong. The connection diagram lists 
a 5V pin for an antenna voltage supply and there seems to be a dedicated 
circuit for short/open circuit detection, but there's no DC blocking cap in 
the antenna feed line.

I'm starting to believe that this board was not originally designed for a LEA-
M8 at all. In fact it was probably made for a LEA-6T, the open/short antenna 
detection looks a bit like the circuit shown in figure 47 in the LEA-6 HIM. 
Also, the LEA-6 modules have an internal DC block in the antenna input so you 
would not need an external one.

Regards,
Matthias

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Radio Controlled Clocks

2020-12-27 Thread ew via time-nuts

In the 90's Junghans came to Miami to test reception because it was the 
farthest from Colorado and I coordinated their visit because I knew the then 
owners. They subsequently shipped me 2 analog, 2 digital clocks and 2 watches. 
The metal watches had an antenna in the leather watch band. The leather watch 
bands deteriorated over time but all 4 clocks still work and switch and adjust 
in Palm City 100 miles north of Miami                                           
                                Bert Kehren                                     

In a message dated 12/27/2020 9:02:05 AM Eastern Standard Time, 
petervince1...@gmail.com writes: 
Hello Andy,

    I have an old Maplin digital LCD clock for MSF, and that is always
about a second slow, but the Coopers analogue clocks are MUCH closer, as is
the Junghens DCF digital LCD clock.  But the Junghens DCF clock always
misses one or other of the DST changes!

    Peter

On Sun, 27 Dec 2020 at 12:11, Andy Talbot  wrote:
>
> With this talk of Radio Controlled clocks...
> I have three domestic RC clocks here, receiving the UK 60kHz signal, MSF.
>  However, I notice that when compared against a GPS clock, timed from the
> 1 PPS signal & NMEA output, they all are a few hundred milliseconds fast,
> ie the display changes just before the GPS derived time.
...
...
> I only ever have digital display clocks, so wouldn't know if the same
> happens with round ones with hands.    Anyone else using domestic MSF or
> DCF77 clocks who have observed this?
>
> Andy
> www.g4jnt.com
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Ublox 8T

2020-12-11 Thread ew via time-nuts

First we do not know how old the units are on ebay, second  you say your board 
has LEA and what does NEO have to do with it. If we find out that these units 
are old I am sure time nuts will find an answer and you will be able to update 
the units you bought.                                                           

                       Bert Kehren                                              

                                      In a message dated 12/11/2020 5:24:56 PM 
Eastern Standard Time, arnold.ti...@gmx.de writes: 
Many thanks to all the timenuts for these interesting informations
concerning *M8T* and for all other good ideas.

My bad, I did not look careful enough to realize that in the ebay
offer mentioned is not a *NEO* M8T but a *LEA* and I did order 2 units
... Fortunately that is not expensive. (Thank you Matthias, I did not
know the difference before!).

No I do not want to build my own module, I do have another problem.
When I bought years ago a professional replacement board from a well
known US-company equipped with the LEA-M8T I got it delivered with the
1st firmware which is not yet capable to work correct with GALILEO
Satellites which I want to receive as well.

The next bad point is, here in Germany I cannot get the new firmware to
update the module (I had asked the representative for M8T). Sending it
back and forth to the US-Company (insured an then on top the customs
problem) is far out to be interesting ... so I falled into the trap with
this offer. I thought to exchange just the receiver on the boards ...
Perhaps somewhen I will find the correct new firmware to load onto the
old original *NEO-M8T* ...

In meantime I will continue working with my good old Thunderbolt.

Many thanks to everybody
  and good and healthy Xmas Time
and good luck for all your projects!

Arnold, DK2WT

Am 10.12.2020 um 10:04 schrieb Matthias Welwarsky:
> Dear all,
>
> If you go shopping for existing breakout boards:
>
> The ebay listing is for the *LEA-M8T*. It is mechanically and electrically
> different from the *NEO-M8T*.
>
> BR,
> Matthias
>
> On Montag, 7. Dezember 2020 14:25:35 CET ew via time-nuts wrote:
>> With not much happening on Ublox 9T I went back looking at 8T in support for
>> Jim Harnan's next generation GPSDO.. Shopping on ebay I ran across this
>> super deal. No financial interest but we have bought from him repeatedly no
>> problem. There is a reason he has 100%.. We have offered $ 15 for three
>> each all accepted.                                            Bert Kehren
>>
>>
>> https://www.ebay.com/itm/ON-SALE-1-U-BLOX-ublox-LEA-M8T-0-10-HUAWEI-GPS-Mod
>> ule/333753811808?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649
>>
>> ___
>> time-nuts mailing list -- time-nuts@lists.febo.com
>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow
>> the instructions there.
>
>
>
>
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Ublox 8T

2020-12-10 Thread ew via time-nuts

Be careful NEO and LEA packages are not even close                              
                                                                                
                                                                                
                                                                                
        In a message dated 12/10/2020 5:26:10 PM Eastern Standard Time, 
paulsw...@gmail.com writes: 
As they say never mind. The 8 T has 1 more pin on each group.
Regards
paul

On Thu, Dec 10, 2020 at 5:16 PM paul swed  wrote:

> Hello to the group and it sounds like someone could create some empty
> boards.
> But I am curious. I looked at Allibaba and see that ublox NEO6 boards are
> available for little cost. Have not looked at the pinouts of the 8T to
> compare but might it be a case of removing a neo6 and replacing it with a
> 8T?
> I have an 8T on order so one way or another will need to do something.
> Regards
> Paul
> WB8TSL
>
> On Thu, Dec 10, 2020 at 10:31 AM Bob kb8tq  wrote:
>
>> Hi
>>
>> I’ve looked at several “you supply the components” outfits. Each time
>> I’ve dug into it,
>> the mechanics of supplying an adequate number of parts has been pretty
>> daunting.
>> None of the things I do is very “high volume” ( 10 is a lot of boards for
>> me ).
>>
>> Bob
>>
>> > On Dec 10, 2020, at 9:21 AM, Mark Goldberg 
>> wrote:
>> >
>> > If you have some volume, consider Small Batch Assembly:
>> >
>> > https://www.smallbatchassembly.com/
>> >
>> > They are not as cheap as the Chinese suppliers, but you can provide
>> > your own components, and it is run by a very helpful gentleman in the
>> > Washington DC area. I got the bare boards from OshPark and you can
>> > order your components from distributors and send them directly to
>> > Small Batch. I preferred using my own parts from known sources, but
>> > they have a stock of components also.
>> >
>> > Regards,
>> >
>> > Mark
>> >
>> > On Thu, Dec 10, 2020 at 6:43 AM Bob kb8tq  wrote:
>> >>
>> >> Hi
>> >>
>> >> If you have a board with many dozens of passive parts on it and
>> >> four or five IC’s getting all those passives down on the board *is*
>> >> very useful. Their price on typical passive parts is low enough that
>> >> the delivered cost is still very close to a bare board.
>> >>
>> >> If you do use odd IC’s you have to move quick. Get the board(s) laid
>> >> out and into them fast. Accept that you may not be in stock next week.
>> >> For things like three terminal regulators or run of the mill digital
>> stuff, they
>> >> seem to maintain a pretty good inventory. Yes, it will be in “their”
>> favorite
>> >> package ….
>> >>
>> >> Bob
>> >>
>> >>> On Dec 10, 2020, at 2:48 AM, Matthias Welwarsky <
>> time-n...@welwarsky.de> wrote:
>> >>>
>> >>> On Mittwoch, 9. Dezember 2020 23:58:51 CET Bob kb8tq wrote:
>>  One note: JLPCB is the only “fab + assembly” outfit I’ve tried.
>> Their boards
>>  are no better / no worse than a lot of other board fab outfits. I
>> have no
>>  idea how they compare to other assembly houses. My selection
>> criteria: “
>>  are they the cheapest I can find?”
>> >>>
>> >>> Currently, you will not find any other fab+assembly service that is
>> as cheap
>> >>> and requiring (almost) no human intervention. For protoype runs with
>> two to
>> >>> five boards assembled there is no competition. I'd say even for 50
>> boards
>> >>> there isn't.
>> >>>
>> >>> The JLCPCB PCBs are ok, the biggest letdown is the solder mask. It's
>> just
>> >>> plain bad. It flakes off on the tiniest rub with a hot iron.
>> >>>
>> >>> The biggest obstacle for sure is the limited parts catalog. They have
>> a decent
>> >>> assortment of passives but almost all active parts come from the
>> "extended"
>> >>> listing (extra cost, 10 uniques only) and they may not stock the
>> footprint you
>> >>> want to use, and the wildly fluctuating inventory.
>> >>>
>> >>> I'm treating them mainly as a layer of convenience. I let them place
>> all the
>> >>> boring passives and maybe a few common actives, but I don't go out of
>> my way
>> >>> to design along their catalog only, knowing that they might not have
>> stock of
>> >>> all the parts anyway when I order the boards.
>> >>>
>> >>>
>> >>>
>> >>>
>> >>> ___
>> >>> time-nuts mailing list -- time-nuts@lists.febo.com
>> >>> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> >>> and follow the instructions there.
>> >>
>> >>
>> >> ___
>> >> time-nuts mailing list -- time-nuts@lists.febo.com
>> >> To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> >> and follow the instructions there.
>> >
>> > ___
>> > time-nuts mailing list -- time-nuts@lists.febo.com
>> > To unsubscribe, go to
>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
>> > and follow the

[time-nuts] Ublox 8T

2020-12-08 Thread ew via time-nuts

Let me clarify I will not make boards. I am willing to work with some one off 
list and design a board and make a Gerber file. Since I have done an Ublox 
board before {attached} I have the Ublox part on file it is the tricky part. 
That board works. Should also be willing to review 8T datasheet so everything 
is covered.                                                                     
   Bert Kehren

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Ublox 8T

2020-12-07 Thread ew via time-nuts

If some one wants to make a breakout board or Saw tooth get with me off list    
                                                        Bert Kehren

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Ublox 8T

2020-12-07 Thread ew via time-nuts

Normally such a price would be suspicious but cut outs from Huawai reduces the 
risk.                                                                      In a 
message dated 12/7/2020 10:26:52 AM Eastern Standard Time, paulsw...@gmail.com 
writes: 
OK I was wondering how to handle that.Thank you.RegardsPaul.
On Mon, Dec 7, 2020 at 10:22 AM ew  wrote:
We will remove them with a heat source and use them on designs we already have 
and tested with 5T and 6T like GPSDO and a Saw tooth correction board using the 
DS 1023- 25  for delay                                                          
                          Bert Kehren                                           
                                                                                
                           In a message dated 12/7/2020 9:48:09 AM Eastern 
Standard Time, paulsw...@gmail.com writes: 
Bert Very attractive price. They appear to be on a cut out circuit board.How 
are you connecting to them please? RegardsPaul.WB8TSL
On Mon, Dec 7, 2020 at 9:14 AM ew via time-nuts  
wrote:
With not much happening on Ublox 9T I went back looking at 8T in support for 
Jim Harnan's next generation GPSDO.. Shopping on ebay I ran across this super 
deal. No financial interest but we have bought from him repeatedly no problem. 
There is a reason he has 100%.. We have offered $ 15 for three each all 
accepted.                                             Bert Kehren               
                                                                                
                                                 
https://www.ebay.com/itm/ON-SALE-1-U-BLOX-ublox-LEA-M8T-0-10-HUAWEI-GPS-Module/333753811808?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Ublox 8T

2020-12-07 Thread ew via time-nuts

We will remove them with a heat source and use them on designs we already have 
and tested with 5T and 6T like GPSDO and a Saw tooth correction board using the 
DS 1023- 25  for delay                                                          
                          Bert Kehren                                           
                                                                                
                           In a message dated 12/7/2020 9:48:09 AM Eastern 
Standard Time, paulsw...@gmail.com writes: 
Bert Very attractive price. They appear to be on a cut out circuit board.How 
are you connecting to them please? RegardsPaul.WB8TSL
On Mon, Dec 7, 2020 at 9:14 AM ew via time-nuts  
wrote:
With not much happening on Ublox 9T I went back looking at 8T in support for 
Jim Harnan's next generation GPSDO.. Shopping on ebay I ran across this super 
deal. No financial interest but we have bought from him repeatedly no problem. 
There is a reason he has 100%.. We have offered $ 15 for three each all 
accepted.                                             Bert Kehren               
                                                                                
                                                 
https://www.ebay.com/itm/ON-SALE-1-U-BLOX-ublox-LEA-M8T-0-10-HUAWEI-GPS-Module/333753811808?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Ublox 8T

2020-12-07 Thread ew via time-nuts

With not much happening on Ublox 9T I went back looking at 8T in support for 
Jim Harnan's next generation GPSDO.. Shopping on ebay I ran across this super 
deal. No financial interest but we have bought from him repeatedly no problem. 
There is a reason he has 100%.. We have offered $ 15 for three each all 
accepted.                                             Bert Kehren               
                                                                                
                                                 
https://www.ebay.com/itm/ON-SALE-1-U-BLOX-ublox-LEA-M8T-0-10-HUAWEI-GPS-Module/333753811808?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] GNSS Correction

2020-12-04 Thread ew via time-nuts

Trimble is working with SIRIUS XM to send Trimble RTX GNSS correction data to 
vehicle satellite receivers for Autonomous Vehicles                             
                             Bert Kehren

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] PM6681 PROMs v109

2020-11-13 Thread ew via time-nuts


On 11/13/2020 2:21 PM, ew via time-nuts wrote:

Having contacted several time nuts off list to cut down traffic but no response 
will some one tell me the battery number  covered   and number of cells so I am 
properly prepared to exchange.


Bert

The backup battery really has nothing to do with the PROMs (Subject of 
this thread). It backs up, when the counter has no AC power, a section 
of SRAM memory. That memory holds a calibration constant that affects 
the accuracy of the counter's interpolation method for measurements. 
This memory also holds more mundane things like save and recall of 
counter user setups.


The backup battery is a single standard CR2032-style lithium 3V coin 
cell. To open the case there are 3 torx head screws. One in the bottom 
center (T10 size) and two at the back plastic feet (T20 size). I started 
the opening process by prying with a small screwdriver in the cracks 
between the plastic front panel and the case.


To keep the RAM memory intact, the counter must have AC applied and be 
in Standby. To remove the battery the holder has openings toward the 
front of the counter where you gently pry up the battery. I used a 
plastic screw driver adjustment tool. The new battery easily slides in 
the way the old one came out. For maximum long term goodness avoid 
touching the new cell with bare hands (possibly a bit too anal-retentive).


Hopefully a small pic I took of the battery location will be attached.

-Rex


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] PM6681 PROMs v109

2020-11-13 Thread ew via time-nuts

Having contacted several time nuts off list to cut down traffic but no response 
will some one tell me the battery number  covered   and number of cells so I am 
properly prepared to exchange.                                          Thanks  
 Bert   Kehren   In a message dated 11/13/2020 4:37:29 PM Eastern Standard 
Time, r...@sonic.net writes: 
I have a Fluke PM6681 Counter On the ko4bb site there is an image of the 
counter's v1.05 PROMs. I just pulled the v1.09 PROMs from my counter and read 
out the contents. I have placed the result 
here:http://www.xertech.net/pm6681/Fluke_PM6681_Counter_PROM_v109.zip Anyone 
interested, please download. If you see any issues or improvement suggestions, 
please let me know.  If all is well in a few days I'll look into uploading this 
to ko4bb.  Back story below I have been following and participating in 
the thread "Frequency Counter Choice". There has been a long discussion about 
the PM6681/Cnt-81 counter, mostly about saving and restoring one calibration 
parameter that gets lost if the internal backup battery dies. A method was 
described, but currently seems unresolved if the restore method works as hoped. 
This promped me to open my PM6681 and ensure the battery was good. Having done 
that, I knew about the v1.05 PROM image but had never seen a v1.09 image. I 
decided to unplug the AC power and carefully remove the two v1.09 PROMs from my 
counter. I read out their contents with a reader/programmer tool I have. I 
returned the PROMs to my counter, applied AC, and the counter seems to be 
working fine. The link provided above is my sharing of the results of this 
exercise.  ___time-nuts mailing 
list -- time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] L1/L2 survey antenna $125 new

2020-11-13 Thread ew via time-nuts

It looks like the L1/L2 antenna that was widely discussed a couple of years 
ago. I bought one and it is TNC like in the picture. Bought cable with TNC      

                              Bert Kehren.  In a message dated 11/13/2020 
4:37:26 PM Eastern Standard Time, k8yumdoo...@gmail.com writes: 
Thanks, Bob.  I zoomed in on the image that shows the connector without the
cover,
and it sure looks like a female connector to me (contradicting what the
SparkFun
description says).  I could not determine which handedness applies to the
threads,
however- not quite enough resolution in the photo.

I'm inclined to suspect that this is in fact a standard TNC female
connector.  What
possible motive could an industry have for using a non-standard connector
type
except for meeting some silly FCC regulation (which clearly does not apply
here).

Dana

On Fri, Nov 13, 2020 at 1:34 PM Robert LaJeunesse 
wrote:

> Just spotted this: https://www.sparkfun.com/products/17382
>
> Datasheet:
> https://cdn.sparkfun.com/assets/6/e/a/9/2/BT-147_GNSS_Antenna_Datasheet.pdf
>
> Chokeplate design, 40dB LNA, TNC connector
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Synthesizers for Rb standards (was: Aging 5065A ?)

2020-10-13 Thread ew via time-nuts

Most Rb's have a filter prior to the multiplier forcing you to make major
modifications to the cell.
Bert
Kehren
In a message dated 10/13/2020 2:51:53 PM Eastern
Standard Time, att...@kinali.ch writes:
On Wed, 7 Oct 2020 10:22:43 -0400
Bob kb8tq wrote:

> People have successfully mounted eBay synthesizers in 5065’s. They work
> and it is one way to take care of that.

Some time ago, I had a "quick" look on how I would design
a synthesizer for an Rb vapor cell standard. The way I
came up with is pretty much the same as in [1]. There are
several ways to get to 6.9GHz that mostly differ by the
frequency they start from but are otherwise relatively
equivalent. E.g. my favorite is using a 125MHz oscillator,
then multiply *3*2 = 750MHz, multiply that further *8 = 6000MHz.
Use 750MHz to feed a DDS generating a 41MHz output, mix that
with 125MHz to get 84MHz, mix that with 750MHz to get 834MHz,
mix that with the 6000MHz to get the desired 6834MHz. This has
the slight advantage that the closest harmonic of 41.7MHz
to 6'834.682MHz is an even harmonic (164) while for 34.7MHz,
as used in [1] it's an odd harmonic (197).

The reason for this "complicated" way of getting up to 6.9GHz
is to use the DDS at a relatively low frequency, which gives
the system a higher resolution and also makes the close-in
spurs easier to filter, if you feel like doing so.

As for spurs in DDS, most of them come from the DDS word being
smaller than thee phase accumulator word. This kind of gives
you a wobling, like in a first order delta-sigma modulator
(which it basically is). Most of the DDS I have seen use a
19 to 20 bit phase->sine core (most likely some CORDIC variant).
The reason for this is that the number of transistors used
(and thus the cost and power consumption) goes up with the
square of the number of bits. And at this level, the INL of the
DAC of the DDS starts to dominate the spurs.

I talked a bit with Claudio about the design of [1] and he
told me that the most difficult thing is getting to above
1GHz with low noise. After that it's easy sailing and the
rest is pretty easy to get good enough. Several of the groups
who do research on Rb vapor cells use the devices built
by INRIM and so far I have not seen anyone reporting that
the electronics are limiting them (this includes some emails
I exchanged with people from UniNE).

If anyone wants to use that design, I am pretty sure the
people at INRIM are happy help you with that.

Attila Kinali

[1] "Simple-design ultra-low phase noise microwave frequency
synthesizers for high-performing Cs and Rb vapor-cell atomic clocks",
by B. François, C. E. Calosso, M. Abdel Hafiz, S. Micalizio,
and R. Boudot, 2015
https://doi.org/10.1063/1.4929384

--
The bad part of Zurich is where the degenerates
throw DARK chocolate at you.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Help needed with frequency standard

2020-09-29 Thread ew via time-nuts

Look at the SRS FS740 and you get an idea how "good" the PRS10 Rb is! Bert 
Kehren In a message dated 9/29/2020 2:22:13 PM Eastern Standard Time, 
m...@alignedsolutions.com writes: 
I would be curious to hear from those who have a GPS disciplined PRS 10 in 
their home time labs.  I was never that impressed with the performance of one 
of mine in that configuration from a 10 MHz ADEV perspective (I did try making 
a few parameter changes.) I ended up essentially free running mine but would 
occasionally apply a 1pps signal to mine as means of adjusting its output 
frequency on an as needed basis.  

I may try this again with a different PRS10 (the 1pps output on the unit in 
question failed a few years ago but I have a spare that has been recently put 
into service.)  Perhaps the second unit will work better.  Both units were 
obtained via the usual auction site.

Mark Spencer
m...@alignedsolutions.com
604 762 4099

> On Sep 29, 2020, at 8:02 AM, Luiz Alberto Saba  wrote:
> 
> Hi guys
> 
> 
> I want a stable & reliable frequency standard.
> 
> I do NOT have a cesium beam.
> 
> I DO have a lot of gpsdos and some rubidiums.
> 
> Since I have one PRS-10 and this device has a 1 pps input, you already know 
> what I'm thinking...
> 
> What I have:
> 
> Trimble Thunderbolt
> 
> Trimble UCCM
> 
> Symmetricom UCCM
> 
> Samsung UCCM
> 
> HP 58503A
> 
> TruePosition
> 
> Oscilloquartz Star 4+
> 
> and a little board with a ublox LEA 5T and 1 pps output.
> 
> Which device is more suitable for disciplining the PRS-10?
> 
> My gps antenna setup is:
> 
> Symmetricom 58532A on the top of the water tank of my building with a very 
> good sky view.
> 
> A Raven Industries LA-21-1575-100-T. About 50 m of RG6.
> 
> A Symmetricom antenna distributor (don't remember the code but is the 4 
> outputs one)
> 
> By the way... Someone knows the delay of the inline amplifier and the antenna 
> distributor? (for Lady Heather)
> 
> Mark Sims is out there reading this list? I'm having problems with LH 6.14 
> and the UCCM units.
> 
> Any help you can give me will be welcomed.
> 
> 
> Thanks
> 
> 
> Luiz Alberto Saba
> 
> from Santos - São Paulo - Brazil
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.

2020-09-27 Thread ew via time-nuts

You want a substantial UPS go to  Victron Energy and get a charger Inverter 
Multi Plus and add a battery I have done it. Bert KehrenIn a message dated 
9/26/2020 12:16:16 PM Eastern Standard Time, m...@alignedsolutions.com writes: 
A few decades ago I  worked with some quite large Telecom gear that ran from 
208 volt AC.    The equipment had its own internal 48 volt supplies and short 
term battery back up system (basically so the redundant CPU units could 
gracefully shut down in the event of a power failure.)  The manufacturer also 
sold similar systems that ran from customer supplied 48 volts but many 
enterprise customers who already had large UPS systems and back up generators 
preferred the versions that ran from 208 volt AC.  

Some smaller office phone systems back in the early 1990's also featured large 
external battery packs to get multi hour run times.  The vendors would 
typically send technicians out to peridoically check the battery systems.  The 
few that I was able to examine were typically made up from 2 volt sealed lead 
acid cells.  The used cells used to be some what available to hobbyists as the 
tended to get replaced before they failed.

Yes some large UPS systems don't work very well at supplying low levels of 
power for long the periods.  During a multi hour maintenance shut down at work 
a few decades ago we had one device that we hoped to keep running (essentially 
a small digital voice play back unit that played phone system messages, ie. 
"The number you have reached is not in service.")  It drew well under 100 watts 
and was the only load at the time for a large UPS system with multiple battery 
banks which stopped running after a few hours and I had to re record the 
messages.  None of us were very surprised.

Mark Spencer
m...@alignedsolutions.com
604 762 4099

> On Sep 26, 2020, at 12:33 AM, Hal Murray  wrote:
> 
> 
>>> Can't I just use a high quality APC backup power system
>>> like we use to power racks of gear in our Telco and compute closets?
> 
>> Very few UPS's are good at long-run applications, they are typically built to
>> run a heavy load for minutes, not a tiny load for hours or even days on end.
> 
> That matches my expectations, but somebody might expect their telco gear to 
> stay up longer than the few minutes it takes to cleanly shut down a computer.
> 
> Is there a branch of UPS gear aimed at telco rather than computers?  That is 
> good efficiency at low power and long time rather than high power for short 
> time.
> 
> Does all telco gear that is expected to run off UPS take 48V?
> 
> Is there a market in small 48V supplies with UPS option for the telco market? 
>  
> You would have to build a 48V to 24V converter rather than the whole thing.  
> You can probably get a brick for that.
> 
> 
> 
> -- 
> These are my opinions.  I hate spam.
> 
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
> 

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] AGM Batteries

2020-09-26 Thread ew via time-nuts

Sonnenschein has a nice application note on AGM  Learned a lot talking with 
their experts 15 years ago, now retired                
http://www.sonnenschein.org/PDF%20files/GelHandbookPart1.pdf        some trivia 
before Unification Berlin had a huge Sonnenschein Battery Bank to prevent power 
outages.

 Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.

2020-09-26 Thread ew via time-nuts

We have done exactly that not a week at a time because we have enough high
resolution and did it in 1 Volt steps down to 20 V no change. Current stays the
same. Bert Kehren In a message dated 9/25/2020 8:44:02 PM Eastern Standard
Time, p...@phk.freebsd.dk writes:

Mark Spencer writes:

> The bit I am struggling with re using a 24 volt battery system in this
> application is what happens when AC power is removed and the terminal
> voltage of the battery starts to fall.

Don't overengineer your supply (unless you absolutely want to :-)

It looks like the BVA is specified at 24V ±10%, which is 21.6-26.6V.

Nobody says 24 Volt is optimal in that interval, and I have
never been able to measure any difference on any OCXO, as long as
I stayed a few hundred millivolts above the lower limit.

I would run the BVA for a week at 24V, collecting PPS data against
a GPSDO or other suitable source.

Then I would run it for a week at 22V, collecting the same data.

If I could not tell the data from the two runs apart, I would design
a 22V supply.

The BVA is spec'ed at 3W steady state, at 22V that's ~150mA.

In long-run applications you get the name-plate capacity, so two
12V x 15 Ah VRLA blocks would keep your BVA happy for four days,
24Ah would last a week etc.

"Small" come from a lot of dubious manufacturers and which means
badly recycled and impure lead. For a golfcart that doesn't matter,
but it is a big disadvantage in long-run applications like this.

Saving 5 bucks on lead-acid batteries are usually a bad deal in the
long run, but on the other hand, dont say no if serious battery-people
offer you a couple of pre-owned large batteries cheap, just make
sure you can lift them.

Lead-Acid in long-duration applications should not be discharged much
below 1.85 V, and 12 cells times 1.85V = 22.2 Volt. Subtract a
diode drop, and now you know where the 24V±10% spec comes from in
the first place.

At 27.6 V float-charge, your linear regulator will have to deal with
(27.6-22)V * 150mA = .84W.

A LM317 would do a fine job, but you can reduce the voltage drop
and get longer runtime with a PNP based home-brew supply.

The float-charger should be able to power the BVA and also recharge
the battery in less than a day, so with 15Ah blocks, I would aim
for around 1-1.5 ampere.

Your batteries will live longer if they have individual chargers,
so something like a 2x12VAC 40-50W torroid trafo, two bridges, two
caps, two LM317's plus resistors and trimpots will do fine.

Poul-Henning

PS: practical hints:

Your local car-nut-emporium has fuseholders like these for cheap:

https://www.thansen.dk/bil/udstyr/eludstyr/kontakter-ledning-sikring/sikringer/sikringsholdere/sikringsholder-m.-kabel-fladsikring/n-497642816/pn-1939736599

Take two, crimp ring-lugs on one end of them, and bolt them directly
to the battery terminal: one for charger, one for load.

When using them next to batteries, the "contra" diode "backwards
across" the LM317 is mandatory.

"Real" UPS installers often have spare batteries which have been
kept on float-charge but otherwise unused, in case of a failure on
customer site. At end of contract, they dont need them any more.

Telephone people with 2V batteries are interesting too, but their
12V blocks are usually dead by the time the swap them out.

Power-grid people, in particular the nuclear plant people, can also
be a good source very, very good batteries with lots of life in
them still, but be very aware of the weight and the short-circuit
currents.

If you end up with pre-owned liquid electrolyte batteries ("OPzS")
make sure the hydrogen gas can vent safely out of the building.

--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
p...@freebsd.org | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.

Re: [time-nuts] Oscilloquartz BVA has been sold. Thank you all who expressed an interest.

2020-09-26 Thread ew via time-nuts

Victron Energy has a nice application book on their web site the have super
products, I used them on my 64 foot GOFAST. Besides products they also discuss
battery technologies and applications. My hard copy is 15 years old. Here is
the link in English
https://www.victronenergy.com/upload/documents/Book-Energy-Unlimited-EN.pdf
Bert Kehren In a message dated 9/25/2020
9:02:32 PM Eastern Standard Time, p...@phk.freebsd.dk writes:

Bob kb8tq writes:

> Two basic types of SLA / VRLA batteries out there: AGM and Gel. For the AGM
> variety, you want a bit more to your charger.

Yes, if you buy batteries for N * 100K $money, spending more money
on your charger is a good investment.

But if you have two batteries doing float-charge/long-run/tiny-load,
in a benign environment in a corner of your lab, the internal
variance between batteries in that same production lot, will
overshadow any imaginable benefit a fancy charger could bring.

>I haven't worked with Gel cells in a while so they may indeed be easier.

They are for the same reasons they suffer cyclic use better.

But for a float/long-run application, it makes absolutely no difference.

Re: [time-nuts] What do people use for measuring temperature?

2020-09-26 Thread ew via time-nuts

We use a LTC 1013 see LTC Application Note 3 page 6  at least 0.05 C. Good 
enough for us. May still have a board would have to find it, Contact me off 
list. Bert Kehren. In a message dated 9/25/2020 10:46:34 PM Eastern Standard 
Time, hmur...@megapathdsl.net writes: 
 I've got a collection of 1-wire gizmos and USB thumb drives.  They are great 
for many applications but I'm looking for something better/different. I'd like 
something that reads to 0.01 degree or 0.001 degree.  I don't need accuracy.  
What I want is reasonable linearity so I can make pretty graphs. I'd like the 
actual probe to be small enough so I can poke it inside gear like a PC and 
attach it to a crystal. I'm looking for a USB or serial connection so I can log 
the data. Is there an obvious brand/whatever I should be looking at? 
thermistor? thermocouple?  ... I don't care about a display on the device.  I 
don't want a logger, they fill up.  I want to grab the data on the fly and do 
my own logging.  (But I'm happy to use a logger if it will do what I want.)  -- 
These are my opinions.  I hate spam.
___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] OSA 8600 8607 questtion.

2020-09-20 Thread ew via time-nuts

Does any one have information on the two thermistors in the 8600 and 8607.

 Thanks Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Thunderbolt E failing

2020-09-16 Thread ew via time-nuts

I used special order PVC Pipe with end caps, used the drilling mud to encase it 
in the ground. The top cap had a U made up of PVC L's and was removable. 
Initial tests where without any filling. Once convinced it worked I filled the 
pipe with coin bags my local banker got me. Very strong canvas. Filled with 
gravel and sand.and a numbered string attached. Used it from 74 till 93 when I 
sold the home. Dug out 6 inches and filled it with dirt.Never detected any 
moisture.Used a Tracor M100 modified to 60 KHz for comparison it served me in 
Miami till 60 KHz was modified. Bert Kehren   In a message dated 9/16/2020 
1:16:24 AM Eastern Standard Time, hmur...@megapathdsl.net writes: 
 p...@phk.freebsd.dk said:> I later talked to a geologist who knows the Danish 
underground well, and he> estimated I would have needed to drill to at least 
25m depth to escape> seasonal temperature-changes and cited a research paper 
from the 1950'ies> where the did precisely that experiment.  I found a paper 
showing skin depth at 1 year of 3-4 meters for soil, a bit over 1 meter for ice 
and rock. Does a pipe in the ground stay dry?  Or how do you keep in dry?  In 
summer, I'd expect it to be cool and if the humidity in the outside air is 
above X% it would condense in the pipe.  Do you just cover the top to avoid air 
mixing?  Does in need a desiccant?  ... -- These are my opinions.  I hate spam. 
   ___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] LH Question

2020-08-24 Thread ew via time-nuts

As backup I installed LH 5.0 on a laptop with Windows 7 Pro but no RS232. I 
inserted an USB to Rs232 adapter and it recognizes it as com Port 6. LH shows 
no com port. How can I switch it to com port 6? Thanks    Bert Kehren 

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Satelles PNT from Iridium satellites

2020-08-10 Thread ew via time-nuts

Allow me to clarify my GPS involvement. In 1973 TI moved me from Houston to 
Dallas to be part of the start up of calculators. This was followed by Marine 
projects since our chairman was an avid sailor. While working on Loran C my 
boss walked in one day and told me that at a staff meeting he had volunteered 
me to write the GPS proposals. It took me three days to convince him that this 
was not just sitting down and writing a proposal. It took over a month to get a 
team together of experts with at least order of magnitude more skills than me. 
I spend most my time on Pert Charts and reviews. Some coordination with 
Semiconductor on C and P code chips and SBP9900 bipolar 16 bit microprocessor. 
Cost calculation, lost our shirt on underestimating software development a 
first of this magnitude in TI Equipment Group (Military). We bid on two, did 
win both and I was given the choice which one. I picked Manpack. More top notch 
experts where added. Continued with typical program management. Do not recall 
any innovating technical contributions beside packaging. Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Satelles PNT from Iridium satellites

2020-08-10 Thread ew via time-nuts

I did attend those conferences, it was my first ex poser to Dual Mixer, NIST 
presented it for high precision frequency measurements. Still have copies of 
the proceedings.Time is and was key but I do not recall any papers addressing 
using GPS for time distribution as we know it today, and that is what I was 
responding to the question that I answered to. Also writing the proposals and 
attending all project reviews it was never covered. Bert Kehren   In a message 
dated 8/10/2020 10:48:12 AM Eastern Standard Time, kb...@n1k.org writes: 
Hi

From what I saw as the system was developed, the people doing it realized that 
timing
was at the core of the design. If there was a timing problem, nothing was going 
to work.
There were GPS (and before that other sat-nav) presentations at the Frequency 
Control
Symposium for many years. The “big boys” in timing all were involved in GPS one 
way 
or the other. 

NIST was doing time transfer work on GPS before the system was fully up and 
running. 
Their results are (to a great degree) what got everybody believing  that GPS 
*could* 
be a good source of time. Those papers started early and kept on flowing …. 
Until they
put their “stamp of approval” on the technique, I don’t think anybody was ready 
to call it
a super time source.

This is by no means to imply that NIST was the only outfit involved or that the 
others
who also evaluated GPS somehow did not contribute. That’s far from the case. 
The only
point is that NIST got out there early. 

Bob

> On Aug 10, 2020, at 5:09 AM, ew via time-nuts  
> wrote:
> 
> Attached are two pictures from my TI days as program Manager of the first 
> GPS. There was no discussions of consumer use or timing application. Focus 
> was on military application being able to guide a bomb in to a chimney. The 
> cost per device was $ 300 000. Because of my high security clearance I was 
> asked to brief the NSA and CIA on the future of GPS equipment. With my 
> semiconductor background Moores Law and previously involved in consumer 
> calculator development I predicted the size of a brick and $ 3000.  I was 
> declared the company Idiot lost all credibility as a strategic thinker ans 
> subsequently left TI. When Magellan came out with there handheld unit they 
> remembered me and send me one. Still have it. When two years later the units 
> the size of a cigarette pack came out and where given away if you took a 
> Cadillac test drive the asked for it back. I refused. History.Bert Kehren    
> In a message dated 8/9/2020 11:23:33 PM Eastern Standard Time, 
> time-nuts@lists.febo.com writes: 
> I've done some quick research.  I do not see timing as one of the services 
> provided.  I wonder if it can be achieved by just listening into what's 
> already transmitted (like GPS) and do some math on our side. 
> 
> On more broader sense, was GPS originally designed to provide timing service? 
>  Or is it a byproduct of needing to measure location and speed, thus it 
> needed a constant signal, and that using it to sync reference signal is just 
> an ancillary and after-thought use cases?
> 
> --- 
> (Mr.) Taka Kamiya
> KB4EMF / ex JF2DKG
> 
> 
>    On Sunday, August 9, 2020, 9:21:23 PM EDT, Bob kb8tq  
>wrote:  
> 
> Hi
> 
> 
> 
>> On Aug 9, 2020, at 7:03 PM, Tom Van Baak  wrote:
>> 
>> Hi Stu,
>> 
>> There's no problem with a semi-commercial posting here. You've been a member 
>> for a decade and frequent contributor plus the subject matter is exactly 
>> on-topic. So thanks for posting.
>> 
>> I spent a while on your web site and didn't uncover a trove of white papers. 
>> If you could post some URL's that would be appreciated. You don't have to 
>> worry about being less accurate than GPS. I mean, there are often far more 
>> important factors than nanosecond precision.
> 
> To that point ( as accurate as GPS ) ….. GPS is simply a convent comparison 
> system. Saying that 
> this or that is better or worse at this or that tau is *not* the same as 
> saying it has more or less value. 
> It’s simply a system that is out there to be compared to.
> 
> Bob
> 
> 
>> You didn't mention pricing; it's hard to imagine it's as free as GPS so that 
>> seems like another disadvantage to me.
>> 
>> Your comment about fewer satellites is spot on. That will be taken care of 
>> if you give SpaceX / Starlink a call and join that bandwagon. There are 
>> already 597 Starlink [1] satellites up there vs. 82 Iridium [2] satellites, 
>> yes?
>> 
>> If you have entry-level / hobbyist grade evaluation kits I'm sure a number 
>> of us would be very interested to try it out.
>> 
>> Thanks,
>> /tvb
>> 
>> [1] http

Re: [time-nuts] "The Penultimate HP5065 A15"

2020-08-05 Thread ew via time-nuts


10 years ago I started a project to try to improve on the 5065A by buying an 
Optical Unit in Europe and only use the temperature control boards. Temperature 
control with a fan and aging with a DAC based on 20 year experience with my 
FRK. Age, move and Macular hole in the left eye ended that project.

Maybe do a coordinated redesign that is done by multiple members with as the 
final step being taking the Optical Unit and transfer it to the new chassis is 
an option. On the present unit if noise is a goal there are multiple HP 10811 
with varying performance out there and why not bring out the 10 MHz with an 
amp. Has been done. Or an other OCXO? Our answer is a clean up loop with an 
external OCXO. Have good results. With the outstanding performance of my 
HP5065A the policy is hands off, do not even touch the C field dial in order to 
get aging data. Past tests have shown that after changing C field it takes time 
to settle.
Bert Kehren  Palm City  Florida In a message dated 8/5/2020 5:56:17 AM Eastern 
Standard Time, tim...@timeok.it writes: 
   I would like to share with you my thoughts on two important points that 
concern a little all attempts to modify and upgrade the equipment.   In general 
I am very reluctant to modify both the electrically and mechanically, in this 
case, the HP5065A. Modifying, even completely a board, I agree if there is a 
significant improvement, trying to use the existing pinout and, in the need for 
additional connection points, use additional connectors on the board. As 
regards the space on the pcb, smd components can be used whenever possible or 
doughter boards.   Remove boards, transformers or anything else I find 
reluctant, I would prefer to have the possibility of being able to go back to 
the original configuration if necessary.  The area occupied by the optional 
batteries, which I think almost nobody uses, can be used for new electronics.   
Using a switching power supply with better performance I agree and since there 
is already a dedicated DC input on the back of the 5065A I would prefer to use 
the one to connect to an external box that contains the new power supply and 
the management of a backup DC input. This eliminates the need to dismantle 
anything inside the HP5065A.   Another important point is that of the certainty 
of the results of a change. I mean that most hobbyists who have a 5065A, 
including me, do not have the opportunity to measure the proposed improvement 
effects, first of all because they do not have a reference such as an HMaser 
available, nor even such a refined measuring system to appreciate the 
improvements made. I want to remember that between zero and 8kseconds the GPS 
system (e.g. HP GPSDO) in our laboratories has an Adev higher than that of the 
HP5065A and therefore the measure we do in that range is that of GPS, not that 
of rubidium.   For this reason I invite all those who dedicate themselves to 
these very interesting changes proposed to test the results obtained in depth 
and to share them with us with numerical and graphic elements. I take this 
opportunity to thank them in advance for their scientific help.   I want to 
specify that this is my point of view, it is not a rule and not necessarily 
shared by other people.   thankyou ,  Luciano   Luciano P. S. Paramithiotti  
tim...@timeok.it  www.timeok.it   Da "time-nuts" 
time-nuts-boun...@lists.febo.com  A "Discussion of precise time and frequency 
measurement" time-nuts@lists.febo.com  Cc  Data Tue, 4 Aug 2020 13:32:31 -0400  
Oggetto Re: [time-nuts] "The Penultimate HP5065 A15"  Hi   If a more extensive 
rebuild is in the works …..   +/-20V is (as has been observed) not an ideal 
voltage for “modern” electronics.  If you dig into each of the boards, there is 
a lot of “drop it down right now” regulation  done on a board by board basis. 
More or less what might be there:   A1 Synth  A2 Battery Charger  A3 60 MHz 
multiplier  A4 100 KHz divider  A5 Digital Divider (= clock)  A6 1 MHz divider  
A7 AC amplifier  A8 Phase detector  A9 Integrator  A10 OCXO  A11 Rb temp 
control  A12 Rb assembly  A13 5 MHz buffer  A14 Logic  A15 Power supply  A16 
Power for clock  A17 Terminal board  A18 Jumpers ( = alt for A2)  A19 Led Clock 
board   For most uses, A4,A5,A6,A16,and A19 are not required. A2 is just a pair 
of diodes (A18) rather than  a battery charger. A17 is more part of the wiring 
harness than anything else. Looking at what’s left:   A1 synth, this seems to 
be a target for various replacement schemes. Right now, it has a bunch  of 
positive voltage rails with some circuits running on 20V. Replacement likely 
would run on <= +12.   A3 Multiplier. Again a target for replacement in some 
schemes. Same supply as A1 for replacement.  Existing design runs +20 direct to 
a lot of circuits.   A7 AC amplifier. Now runs +/-20V. Pretty much begs for a 
modern op-amp based replacement  board. +/-12 probably is fine for that board. 
A *good* -15 would work for the existing

Re: [time-nuts] "The Penultimate HP5065 A15"

2020-08-02 Thread ew via time-nuts


Having one of the best HP5065A Rb's that Corby has seen right at 4 E-14 at 200 
and 400 sec. I have been hands off. My age and macular hole on my right eye has 
impacted my hardware work. A recent test also shows very low aging over a 9 
month period. But last September my environmental monitor was with Tom. The 
last month I have spend strictly on temperature to better understand what lab 
temperature effects the Rb.  This moment a 48 hour frequency test is in the 
works because there is a tropical storm that was a hurricane  20  miles east 
from me. Hope there are no power failures because the Rb is not on a UPS but 
like all my frequency equipment is on a Power Line Conditioner including the 
Rb. No power failure I will be able to share frequency versus pressure and 
temperature.

 

C field control Corby included by my request a fine control using a Vishay trim 
pot, knowing what I know today I would make the trim pot the coarse and the 
original Hp the fine. There is little need for coarse adjustment.

 

On the A 15 subject I keep hands off but Juerg is making some changes. In the 
AC mode there is up to 20 W heat generated between the transformer and the 24 V 
DC input. Our answer is a Buck Converter on the output of the AC supply down to 
16 V for the Li Ion module that in turn feeds a Mean Well SD-50A-24 DC?DC 
converter. It 24 V output is not adjustable but that is a small price to pay. 
We have done tests feeding an OSA 8600 directly and have not seen any 
degradation. But in this case the A 15 board still does its part. The parts are 
not in the Rb but behind on the back.

 

A pressure, temperature and two DAC board is in the works.

Next hurricane the tests will be on a FRK/M100 because that will be my future 
HP5065A replacement.

 
Bert Kehren Palm City Florida 
 In a message dated 8/2/2020 4:38:31 AM Eastern Standard Time, 
time-nuts@lists.febo.com writes: 
Regarding 5065  "A15" When I was about to repair my 5065, the first thing I 
noticed was thequite high "+22-30V" and its impact on the dissipated heat from 
theseries regulator Q1. Therefore, I replaced the power transformer T1and the 
rectifiers with a linear regulated power supply providingfiltered 24V DC. The 
original circuitry incorporated a battery charger A2but since the accus was 
(very) dead, it was replaced with a diodejumper board A18 from a second 
scrapped unit. The original diodesgot hot. They were replaced with modern 
types. I will follow your progress with the new regulator board with great 
interest. Best Regards Ulf 
KylenfallSM6GXV___time-nuts mailing 
list -- time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] EEG TS RFS Rubidium

2020-07-13 Thread ew via time-nuts

It is taken
In a message dated 7/13/2020 4:56:05 PM Eastern Standard Time, 
time-nuts@lists.febo.com writes:

I was given a working with new capacitors EEG TS RFS. Have no use for it but if 
some one wants it for the cost of shipping be glad to send it . Off list please.
I opened it up, impressed with the optical unit, has any one analysed it,   
with EEG space history is it more than what we find in Telecom units?Bert 
Kehren___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] EEG TS RFS Rubidium

2020-07-13 Thread ew via time-nuts

I was given a working with new capacitors EEG TS RFS. Have no use for it but if 
some one wants it for the cost of shipping be glad to send it . Off list please.

I opened it up, impressed with the optical unit, has any one analysed it,   
with EEG space history is it more than what we find in Telecom units?
Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] low power divide by 5

2020-07-02 Thread ew via time-nuts

161 and 163 are candidates. Back in the early 70's my favorite for my counter 
work  was the 74S112 dual JK. So I went to DigiKey to check on CD74AC112 they 
have in stock so with two of those along with an AND gate you can make as many 
divide as 5 as you need.  Just like the S112 it clocks over 100 MHz!
Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Vibration isolation of quartz oscillators

2020-06-28 Thread ew via time-nuts




Once I get my OSA 8607 back I plan on mounting it along with a FRK/M100 RB in a 
HP chassis. Attached a picture of a vibration  mount for the OSA. Very soft. 
Can not be used for the Rb because of weight but also vibration mounted. The Rb 
is fan cooled with a Sunon MagLev 80X80x15 30db(A) mounted with rubber mounts 
that where sold at one time for hard disk drives. I can not feel or hear any 
thing on the housing.
I turned in to a frequency nut while living in Miami so when I moved to Palm 
City that included massive downsizing the lab down to 9 by 20 feet,  my work 
bench with all instruments except  frequency take up 240X31 inches. The 
frequency instruments are in a short 19 inch rack on the opposite side. Home is 
on a concrete slab and walls are concrete block Miami code. In  the corner a 
half size Sears bench with a half height 19 inch rack. The unit will be placed 
on top which will be eye level. Right now there is soft foam with a metal plate 
will be replaced with 1 inch 18X18 marble. Will experiment with soft foam 
versus bubble pack. My biggest problem is the HP54132A, I have one on each 
side. To much vibration. That is why I bought a FA2. My HP5065A which has super 
AV rests on a shelf mounted on the outside wall since it is not part of my long 
term plan but is needed during testing of the Rb/OSA. The limited space forces 
me to make decisions. 
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Frequency division by 81

2020-06-21 Thread ew via time-nuts

Two 74HC393N and one 74HC86N Dip all for less than $ 2  will do the job
Bert Kehren

In a message dated 6/21/2020 3:57:59 PM Eastern Standard Time, 
k8yumdoo...@gmail.com writes:

Can you stand a few 10's of nano-Hz error in the 162 kHz signal?  If so, a
48-bit
DDS can get you that close to 162 kHz when the 10 MHz is right on.

However, dealing with the off-the air signal would be problematic as has
been pointed
out, not to mention the added complication of the signal having phase
modulation.

I've occasionally entertained myself measuring and plotting the pilot
carrier of a
UHF DTV station about 35 miles from home, and the received signal is
festooned
with all manner of interesting phase "defects".  Fortunately deep dropouts
seem to
be very infrequent.  Admittedly 162 kHz should be rather more stable than
~578 MHz,
but still ...

Have you considered using a good GPSDO?  Although the short term phase
stability
is not real good, it's otherwise a turn-key and fairly straightforward
solution if getting an
accurate 10 MHz local reference is your goal.

Dana

On Sun, Jun 21, 2020 at 1:30 PM Bob Fleming  wrote:

>      French time signal is phase modulated. If I recall correctly.
>
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Frequency division by 81

2020-06-20 Thread ew via time-nuts

On the 15 MHz FE 405 we use an XOR and two Flip Flops  to divide by 3 with a 
symmetrical output. Four of these will give you symmetry and divide by 81
Bert Kehren

In a message dated 6/19/2020 8:14:31 PM Eastern Standard Time, kb...@n1k.org 
writes:

Hi

The biggest issue is that there are so many variables. They never seem
to get nailed down. What you are seeing is the answer to 20 or more 
“niche” requirements.

For instance:

Is the “phase noise” requirement close in or broadband? ECL is in general 
horrible for broadband phase noise. 

Is the source at UHF or below 10 MHz? A CMOS solution isn’t going to make
much sense at 500 MHz. 

Is a square wave ( to drive logic ) part of the system requirement? Since 
in some cases these are corporate sponsored designs (as opposed to
basement projects) even getting into something that simple is “revealing 
too much of our IP”. 

If the destination is an FPGA, they generally have horrible noise performance. 
That’s true both close in and broadband. What’s “good” there is likely pretty
awful in another context. 

What *is* “good phase noise? To one person, it’s -150 dbc/Hz at 100 KHz offset
on a 10 MHZ source. To the next person it’s 40 db better than that.

As long as none of the details are available, the answers are going to be
very difficult to parse. It’s also why people who do this sort of thing spend 
years learning how to do it. 

Bob

> On Jun 19, 2020, at 7:23 PM, Mark Haun  wrote:
> 
> On Fri, 19 Jun 2020 14:49:01 +
> "Poul-Henning Kamp"  wrote:
>> Gilles Clement writes:
>>> Could you point me to a practical design example of a Pi divider ?  
>> 
>> Look at Fig 2 in Enrico's paper:
>> 
>>> http://rubiola.org/pdf-articles/conference/2013-ifcs-Frequency-dividers.pdf
> 
> I saw this a while ago and found it interesting, but not being a proper
> time nut myself, I am wondering: are the advantages of this divider
> architecture maintained if you need a square wave output?  Wouldn't the
> triangle->square conversion introduce its own noise, possibly swamping
> the gains of the lambda divider?
> 
> As an aside, I have noticed that every time this question comes up,
> there are a variety of answers, ranging from "use a PICDIV" to "use this
> fancy low-noise architecture" to "use ECL / HC / modern fast logic
> gates."  I read through the replies but never seem to leave the
> discussion knowing any more than I did at its start.  It would be great
> if someone could provide the context to understand the relative merits
> of each suggestion---how they are likely to stack up against one
> another and how you would choose one over the others.  I.e. please
> spend more time explaining why you are right and everyone else is wrong
> ;)  Otherwise, it's just chaff.
> 
> Mark
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] time sync by moonbounce

2020-05-23 Thread ew via time-nuts

This is a must read. Could not put it down, JPL, NASA,  Eisenhowe,r did learn a 
lot at the same time fascinating
Bert Kehren
In a message dated 5/22/2020 10:36:53 PM Eastern Standard Time, 
jim...@earthlink.net writes:

Apparently, they used moonbounce between DSN stations to synchronize to 5 
microseconds in 1968. It was easier and cheaper than flying cesium clocks 
around. (And the Rb standards weren't good enough).
https://ntrs.nasa.gov/search.jsp?R=19770007245
History of DSN - mostly about politics, history, transmitters and receivers, 
but a whole section on timekeeping, phase measurements, etc. starting around 
page 133 (The DSN Inherent accuracy project), and the discovery during Mariner 
that UTC and UTI were different enough to cause nav errors.
___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] OCXO Support Board

2020-05-14 Thread ew via time-nuts

Thanks Mark for reminding me, spend 3 hours this morning reviewing designs to 
be released. Found a couple of problems. Also went back to look at the OCXO 
boards I released in 2018, found a problem on the board with no Amp, the SMA is 
not grounded. Easy to fix, but if some one wants new Gerber will publish 
it.Always try to have a third party check my designs. To many designs 30 this 
year.
Bert Kehren
In a message dated 5/13/2020 10:18:33 PM Eastern Standard Time, 
hol...@hotmail.com writes:

One thing that I recommend is that after completing the layout is to:1) step 
back and wait a few days2) enjoy a few adult beverages while waiting3) go back 
a re-check everything4) send it out to the board house
You'd be surprised how often simple, subtle, not so subtle 
glitches/tweaks/improvements show up after a pause in the process.
---
> Once you get going, a board is a weekend project. Indeed, a simple board 
> might be anevening project. There’s not a lot involved. 
> ___time-nuts mailing list -- 
> time-n...@lists.febo.comTo unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
> instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] OCXO Support Board

2020-05-13 Thread ew via time-nuts

You give away your age, was there did a lot of it and off to the repro shop and 
than the board manufacturer. All local in Houston.
Bert Kehren
In a message dated 5/13/2020 10:39:48 AM Eastern Standard Time, 
w...@triconet.org writes:

Thank you to all who have written, on and off list, with offers of boards and 
advice on how to make my own.  Much appreciated.

I think I'm on to one that meets my fairly simple needs and uses through-hole 
components.  I have done SMT construction in the past but things have shrunk in 
size by an order of magnitude since then it seems.  (I can remember laying out 
boards by hand, taping up the artwork 4:1, reducing it photographically, 
exposing and etching boards.  So today's technology is magical.)

Many of you are doing some awesome work.  Well done.

Wes  N7WS


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Chinese GPSDOs

2020-04-17 Thread ew via time-nuts

All three seam to be Chinese customer specific devices with focus on time. I 
bought three of the Trimble units we call them Tbolt 2 because of design 
similarities. On LH you will notice one thing like the original Tbolt it shows 
frequency jumps of 1 E -10 but also once every hour it does a major correction 
plus or minus. It is once an hour depending on when powered up. Frequency 
measurements confirm the excursions. The result is a maximum 1 pps excursion of 
 plus minus 4 nsec. This is comparable to the Furuno GT87 and four times better 
than Tbolt 1. All tests are 24 hours against a very good HP 5065A, backed up 
with Cs.
Bert Kehren
In a message dated 4/17/2020 11:52:31 AM Eastern Standard Time, 
time-n...@welwarsky.de writes:

On Freitag, 17. April 2020 16:04:15 CEST Steve - Home wrote:
> There are some Chinese GPSDOs currently on eBay, containing a Symmetricom
> 10MHz oscillator and a Furuno GT-8031 GPS receiver. Has anyone had any
> experience with them? It’s hard to tell from the pictures what the power
> requirements are. I know the GT-8031 is an older 8-channel receiver. I was
> considering one for a portable 10MHz reference. Anyone checked these out
> yet?

I own three of them. One of them is the Symmetricom/Furuno combination you 
mentioned. 
Another one has a Samsung OXCO and a Ublox LEA-6T receiver. A third one is 
supposedly a 
Trimble OXCO, but I have no idea which GPS receiver it is using. It's the only 
one in an 
enclosure and I didn't bother yet to open it.

They're all basically identical in form and structure. Same form factor, same 
inputs and 
outputs. I even bothered to make an adapter PCB with a switching regulator so 
that I can 
operate them more easily. They operate on 5.5V, taking in a little over 2A 
while the OCXO 
heats up.

I have no equipment yet to assess their performance. Anyway they're all scrap 
telecom 
equipment, many of them are unchecked and damaged, with components missing 
(ripped 
off of the PCBs), cables cut. The OCXOs are genuine as far as I can tell but 
they all have 
undocumented service life and you don't know what they have been exposed to 
mechanically.

If you plan to order one, I suggest to get one with an Ublox receiver. The 
Furuno is likely 
the oldest and weakest, it's also GPS-only. Afaict, the LEA-6T can at least 
receive GPS and 
GLONASS. From all three, I like the Samsung best, going by the performance I 
see when 
connecting it to "Lady Heather". The Symmetricom is the worst. Probably the 
OCXO has 
taken a hit.
The Trimble is so-so.

Of course there's a thread on the EEVblog forum dealing with all their variants:

https://www.eevblog.com/forum/projects/a-look-at-my-symmetricom-gpsdo-(ocxo-furuno-receiver)/[1]

HTH.

BR,
Matthias
> 
> Steve
> WB0DBS
> 
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow
> the instructions there.

[1] 
https://www.eevblog.com/forum/projects/a-look-at-my-symmetricom-gpsdo-(ocxo-furuno-receiver)/
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Phase measurement of my GPSDO

2020-04-13 Thread ew via time-nuts

If you have an extra 10811 use it as an offset all mine tune 20 Hz + and I have 
used it as offset at 5 MHz , 10 Hz at 10 MHz all will do.
Bert Kehren
In a message dated 4/13/2020 5:07:38 PM Eastern Standard Time, tplu...@ieee.org 
writes:

Hi Bob
awesome, thanks! of course it is 1e6, not 1e7, I got a mistake :-)

Maybe I have some good OpAmps for this purpose in my box. I will try it! of
course I saw that my setup was not ideal as there was a bit of noise on the
signals which I guess does lead to some jitter in the trigger circuit and
therefore decreases my measurement noise floor.

Can you say something about how it would be done using a TIC?
I don't have two identically good counters, but the HP 5335A could be used
as TIC, couldn't it.

And the offset source I used is not directly the HP 10811, but the HP 8663A
Signal generator internally uses a 10811 as reference source. But I didn't
wait for days for it to warm up properly. (Should I?)

> Fun !!!
Yea, of course! :-)
I already implemented the ADEV, MDEV and TDEV calculations in Matlab by
myself. I use TimeLab to see what numbers I should expect, and then I want
to compute it all myself in Matlab because I want to see how it actually
works. ;-)


Best
Tobias



On Mon, Apr 13, 2020 at 10:50 PM Bob kb8tq  wrote:

> Hi
>
> Ok, first the math:
>
> If your offset oscillator is 10 Hz high at 10 MHz, you have a:
>
> 10,000,000 / 10 = 1,000,000 : 1 multiplier in front of the DMTD
>
> You get to add a 6 to what Time Lab shows you.
>
> If you are getting an ADEV at 1 second of 1x10^-4 then that multiplier
> gets you to 1x10^-10
>
> So, what’s going on?
>
> You can’t feed the mixer outputs straight into a counter. The counter
> front
> end does not handle LF audio sine waves very well. You need to do an
> op-amp based limiter. A pair of OP-37’s in each leg ( or something
> similar)
> should do the trick.
>
> Second, the offset source needs to be pretty good. A 10811 tuned high with
> both the mechanical trim and the EFC is a pretty good choice to start out.
>
> If you only have one counter, simply ignore the second channel. You are now
> running a single mixer. It still works as a comparison between the offset
> oscillator
> and your DUT.
>
> If you want to do it properly as a DMTD, then you set up two counters. One
> to measure mixer A and the other to measure mixer B.  Set them both up to
> measure frequency. Time tag the data files so you know which reading
> matches up with which.
>
> Fun !!!
>
> Bob
>
> > On Apr 13, 2020, at 3:18 PM, Tobias Pluess  wrote:
> >
> > Hi again Bob
> >
> > I tried to do some measurements with a DMTD!
> > In my junk box I found a little PCB from earlier experiments on that
> topic,
> > with a power splitter and two SRA-3H mixers, it was even already wired
> for
> > the DMTD configuration. So I gave it a try!
> > As "transfer oscillator" I used my HP 8663A signal generator, and set it
> > high in frequency by 10 Hz. To the two mixers, I connected the two 10MHz
> > signals and at the mixer outputs, I put a little lowpass filter with
> 100Hz
> > corner frequency.
> > The output signals from the two SRA-3 mixers are almost 0.5Vpp, so I
> tried
> > to feed them directly into the HP 5335A TIC and used the TI mode to
> measure
> > the delay between the two signals.
> > This gives 10 readings/sec, which I try to process with TimeLab.
> > It does give some interesting graphs, but I don't know yet how to
> correctly
> > set up TimeLab for this kind of measurement. I.e. now, I get an ADEV in
> the
> > order of 1e-4 (at tau=1sec) to 1e-5 (at tau=500sec). So does that mean I
> > simply need to multiply this with 1e-7 to get the *real* ADEV at 10MHz?
> > this would mean that my real ADEV is in the range of 1e-11 to 1e-12,
> which
> > is indeed my target value, BUT I expect that things are not that simple.
> > (i.e. what if I didn't set the transfer oscillator high by +10Hz but only
> > by 9.9Hz for example).
> > Can you give some hints on that?
> > Of course I also did the noise floor test (i.e. I fed the 10MHz signal
> into
> > a power splitter and connected the two outputs to my DMTD with two
> > different lenghts of cables. This gave results starting at 1e-4 going
> down
> > to 1e-7, maybe it would have gone even lower but I measured only for a
> > couple of minutes.)
> >
> > Can you give some hints on that?
> >
> > Best
> > Tobias
> > HB9FSX
> >
> >
> >
> >
> > On Fri, Apr 3, 2020 at 1:45 PM Bob kb8tq  wrote:
> >>
> >>> Hi
> >>>
> >>> The quick way to do this is with a single mixer. Take something like an
> >>> old
> >>> 10811 and use the coarse tune to set it high in frequency by 5 to 10
> Hz.
> >>>
> >>> Then feed it into an RPD-1 mixer and pull out the 5 to 10 Hz audio
> tone.
> >>> That tone is the *difference* between the 10811 and your device under
> >>> test.
> >>> If the DUT moves 1 Hz, the audio tone changes by 1 Hz.
> >>>
> >>> If you measured the 10 MHz on the DUT, that 1 Hz would be a very small
> >>> shift
> >>> ( 0.1 ppm ). At

Re: [time-nuts] Modern Rb atomic reference vs classic Cs

2020-03-17 Thread ew via time-nuts

A couple of years ago Time Tech was selling a OSA 8607 GPSDO with an AV of 8 
E-14. AXTAL has one. Takes a lot of characterization, fully understand and 
constantly compensate the OCXO and continous GPS monitoring for more than 24 
hours. W. Schaefer has the smarts. Does not have the aging  of a Maser.Not 
having their smarts I am trying to do something close using aging compensation 
along with pressure and temperature on a FRK/M100 Rb and use a 8607 for clean 
up. Will use multi day GPS averaging for fine control. Presently running 4 Rb 
to pick the best. Use HP5065A for AV and Datum RS 2000 for frequency ,does 24 
hour GPS averaging. Have 5061B with new small tube.
Bert Kehren

In a message dated 3/17/2020 4:52:23 PM Eastern Standard Time, att...@kinali.ch 
writes:

On Sat, 14 Mar 2020 14:50:45 -0400
Bob kb8tq  wrote:

> A brand new 5071 with that tube appears to be over $90,000 these days. Based 
> on 
> running one for a lot of years, After about 6 years of operation, you will be 
> sending 
> it back for a new tube. By the time the unit is back in your lab, the refit 
> will cost 
> roughly half the price the whole unit cost new …. gulp …..

At those prices, I'd rather go for a µQuans or SDS Rb clock.
Those don't lose atoms like the Cs beam does and thus don't need
a refill. Their lifetime is more likely in the decades than just
a few years. Weakest link, as far as I know, are the lasers.
And yes, after the second, at latest after the third Cs tube,
these Rb devices are cheaper. And they are as much a primary
standard as the 5071 is.

On Sat, 14 Mar 2020 13:57:21 -0700
Hal Murray  wrote:

> Can the physics-nuts calculate the Rb frequency relative to Cs?

Theoretically yes, practically no. While we "know" exactly what
each electron in the atom is doing and how it interacts with each
other electron and the nucleus, there are so many of them that there
is no closed form solution (c.f. three/many body problem). As far
as I am aware of, nobody has even done a complete numerical model.
So all the calculations we have today are approximations that
bunch most if not all inner electrons together and approximate them
by an average field.

> What's missing on a gas cell?  Is the problem theory or implementation?

Both. For one, you cannot control all parameters during production
well enough that a calulated shift would be any more accurate.
For another, there are quite a few shifts in the system, from
buffer gas shift (dependent on exact composition) to light shift
to RF power shift to RF field gradient shift to temperature gradient
shift to . Some of them nobody thought of until a PhD student
tried to figure out what the next limiting factor was.

If you would try to make the system as well characterizable as
a Cs beam standard, then you would end up with a product that is at
least as expensive, if not more. If you want to know more, have a look
at the publications, especially the dissertations, by the time/frequency
lab at UniNE: https://www.unine.ch/ltf/home/publications.html
They go into quite detailed analysis of what the different shifts are
that are affecting the long term stability of Rb vapor cells.

            Attila Kinali

-- 
    The bad part of Zurich is where the degenerates
                throw DARK chocolate at you.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Time-Nutters-- Adding Rubidium to a Thunderbolt...?

2020-03-02 Thread ew via time-nuts

It is very simple to do. Warren did it I think seven years ago and we have done 
it repeatedly in the last 4 years. Take the EFC that goes to the OCXO to the C 
field control and Tbolt can determine and automatically adjust to frequency per 
Volt. You can also adjust the time constant. Tbolt is ideal for that 
application. We do not use it because in all cases Tbolt uses 0.1 sec 1E-10 
frequency jumps to adjust for time. At the kind of work we do it causes some 
problems.
Bert Kehren
In a message dated 3/2/2020 1:21:22 AM Eastern Standard Time, 
mp...@clanbaker.org writes:

Hello, Time-Nutters--
Is it possible to add/combine/mate a rubidium osc to a TrimbleThunderbolt GPSDO?
Have there been any examples of this that I could use as a guide?
Thanks for any info/feedback on this!!
Mike BakerGainesville/MicanopyFlorida USA***

___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] New Subscriber, DIY GPSDO project (yes, another one)

2020-02-27 Thread ew via time-nuts

Please contact me direct off list
In a message dated 2/27/2020 4:46:32 PM Eastern Standard Time, 
time-n...@welwarsky.de writes:

On Donnerstag, 27. Februar 2020 19:16:22 CET ew via time-nuts wrote:
> Matthias where are you located. I am in the US but I have some partners in
> crime that may be able to help you with AV testing    ewkeh...@aol.com
> 
> Bert Kehren

I'm in Germany.

BR,
Matthias

> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow
> the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] New Subscriber, DIY GPSDO project (yes, another one)

2020-02-27 Thread ew via time-nuts



Matthias where are you located. I am in the US but I have some partners in 
crime that may be able to help you with AV testing    ewkeh...@aol.com

Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] 5.115 MHz / 10.23 MHz wanted

2020-02-26 Thread ew via time-nuts

The first HP10544 I held in my hand  was 10.23 MHz part of the GPS project.
Bert Kehren
In a message dated 2/26/2020 4:26:42 AM Eastern Standard Time, 
time-nuts@lists.febo.com writes:

For a DIY project I'd like a 5.115 MHz OCXO. That weird-looking number is half 
the basic 10.23 MHz GPS chip rate.
I realize it's trivial to create 5.115 MHz with a DDS chip, a function 
generator, synthesizer, or even an aggressive phase microstepper. But in this 
case, if possible, I'd prefer a simple single part; a plain old XO or OCXO 
solution. Do any of you know where to get a 5.115 MHz crystal or oscillator?
I'm pretty sure that I've seen one-off surplus 10.23 MHz or 5.115 MHz OCXO on 
eBay but I never thought to bid on them because the frequency was strange. If 
you saw one, and "bought before you thought", let me know.
Thanks,/tvb

___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Frequency standards for different tau in Allen Dev measurement

2020-02-21 Thread ew via time-nuts

You missed my favorite  HP5345A  only direct 500 MHz and internal 500 MHz, only 
recently replaced it with 53132A still use it for 40 GHz work
Bert Kehren

In a message dated 2/21/2020 7:27:32 AM Eastern Standard Time, 
mag...@rubidium.se writes:

Hi Taka,

On 2020-02-21 04:45, Taka Kamiya via time-nuts wrote:
> I was in electronics in big ways in 70s.  Then had a long break and came back 
> to it in last few years.  Back then, if I wanted 1s resolution, the gate time 
> had to be 1s.  So measuring ns and ps was pretty much impossible.  As I 
> understand it, HP53132A (my main counter) takes thousands of samples (I 
> assume t samples) to arrive at most likely real frequency.  That was 
> something I had hard time wrapping my head around. 

It actually does two things.

First, it interpolates the occurrence of a rising edge (for start and
stop channel), so if this does not happen in perfect alignment with a
rising edge of the reference/coarse clock. Often the OCXO/Rubidium is
for 10 MHz,  but then a 90-500 MHz oscillator is locked to the
reference, and this higher clock is then used instead of the 10 MHz for
coarse-counting. Coarse-counting is counting of cycles just back in the
good old days of counters. The resolution is increased further not by
raising the counting frequency, but by measuring the time-error of the
trigger channel event in relation to the coarse-counter clock-edge.
Thus, measuring 0.000-0.999 of a coarse-counting cycle. In practice it
becomes hard to design for that, as the shorter end has problem is gate
delay times to be well decided, so one add one or two coarse cycles to
do 1.000-1.999 or 2.000-2.999 cycles, but these extra cycles is only for
the interpolator design, so once the fractional cycle is known the other
can be ignored.

Just to give you an idea of what different counters do, here is from the
top of my head some numbers:

HP5370A: Ref 10 MHz, Coarse 200 MHz, Interpolation gain 256, time
resolution < 20 ps
HP5328A: Ref 10 MHz, Coarse 10 MHz, Interpolation gain 1, time
resolution 100 ns
HP5328A with Option 040-042 and HP5328B: Ref 10 MHz, Coarse 100 MHZ,
Interpolation gain 1 (TI-average has other interpolation means), time
resolution 10 ns or for TI-avg 10 ps (claimed)
HP5335A: Ref 10 MHz, Coarse 10 MHz, Interpolation gain 200, time
resolution 1 ns
HP5372A: Ref 10 MHz, Coarse 500 MHz, Interpolation gain 10, time
resolution 200 ps
HP53132A: Ref 10 MHz, Coarse 100 MHz, Interpolation gain 1000, time
resolution 100 ps
SR620: Ref 10 MHz, Coarse 90 MHz, Interpolation gain 512?, time
resolution < 25 ps (don't recall details)
PM6863: Ref 10 MHz, Coarse 500 MHz, Interpolation gain 1, time
resolution 2 ns
CNT-90: Ref 10 MHz, Coarse 100 MHz, Interpolation gain 512, time
resolution 100 ps (claimed)
CNT-91: Ref 10 MHz, Coarse 100 MHz, Interpolation gain 512, time
resolutions 50 ps (claimed)
SIA3000: Ref 100 MHz, Coarse, 100 MHz, Interpolation gain 5, time
resolution 200 fs

As I write claimed above, the actual performance can be better, but the
spec on the sheet did not overstate it more. While all the numbers may
not be 100% correct, I think they help to illustrate the relationships
very well. As you calculate the length of the coarse counter period from
it's frequency, and then divide with the interpolation gain, which is by
how many steps the period is interpolated, the raw time resolutions pops
out.

Interpolation methods differs, but typically first an error signal is
generated and then it is stored into a capacitor which is then measured
with some slower technique. The 5335A use a very simple technique where
the discharge of the capacitor is done with a much lower current than
the charging, so now the discharge time can be measured using the coarse
clock. This is called pulse-stretching. Today the far most common
technique is to use an ADC to digitize the voltage.

The 5328 counters have a unique interpolation technique by
phase-modulating the reference clock with noise, effectively shifting
the reference transitions around and that way interpolate over time a
higher resolution. It works better than claimed.

Remember that this single-shot resolution is reduced by the trigger
jitter as well as unstability of reference oscillator. In practice the
trigger jitter or resolution dominates as a 1/tau limit as you look at
the Allan Deviation, to fix that you need to buy a better counter or
signal condition for better trigger.

The second trick used in 53132 for measuring frequency is averaging. It
uses an average technique originally from optical frequency measures to
accumulate data into blocks and then subtract the time-stamps of two
subsequent blocks. This is the same as average the output of a number of
overlapping frequency estimations.

This has advantages as white noise is supressed with a steeper slope,
and the associated deviation is the modified Allan Deviation MDEV.

>  
>
> I understand most of what you said, but I've never taken statistics, so I am 
> guessing on some

Re: [time-nuts] Pressure sensitivity of Rb vapor cell standards

2020-02-19 Thread ew via time-nuts




Juerg and I have a few FRK and M100 along with spare bulbs to cover our 
remaining life. We have done extensive testing and learned a lot. We for 
instance have experimented with loop time constant 0.1 to 20 seconds and have 
found out that the best AV is with 1 second. We also did consider using Laser 
Diode to improve AV. My idea was to buy some diodes that cover the spectrum and 
have a friend in Hergiswil that has the optical plug in for the HP 70 000 
series spectrum analyzer characterize and select candidates. Worked with Corby 
on proper optics. Assemble a unit feed a precise frequency in to the unit from 
an external source and use the loop filter to control the C Field. Monitor and 
adjust the Diode. Once the unit shows stability use a PIC ADC input to monitor 
the filter output and with a 1655 control the Diode. The time constant would be 
longer than the 1 second for the OCXO. Now that we both have HP5065A's with 
according to Corby some of the best AV there is no motivation at this age to 
pursue this venue. To many other projects on our plate. Also think an optical 
filter should be reconsidered, Corby did some tests but forgot to change the 
time constant. I have presently 4 units running to find the best long term 
aging for my Maser replacement project. See no change at 1 E-12 changing 
voltage from 22 to 24 V. Slight change while changing but back to same 
frequency after 20 seconds. Also no change 1 E-12 with 2.7 C ambient change. 
Presently no fan control. Aging test will be done with 1 E-14 resolution. After 
3 month of aging test the two best will get fan control for additional tests. 
Goal is to control a Rb in 24 1E-15 steps per day. Ambient pressure is also 
part of the control loop. A OSA 8607 will be the clean up.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Pressure sensitivity of Rb vapor cell standards

2020-02-18 Thread ew via time-nuts

I think a member has been working on it with a couple of 5065's. I think it 
would be easier with FRK and M100, many around with bad or weak lamps. Easy 
access to lamp and optics. We have some ideas but booked for the next 9 
months.Bert Kehren


In a message dated 2/17/2020 7:17:00 PM Eastern Standard Time, 
mag...@rubidium.se writes:

Hi,In the 5065 and most others, the light intensity is not stabilized. It 
should not be too hard to regulate the Rb lamp amplitude and servo it to light 
intensity from the detector. Didn't Poul-Henning check this?Cheers,Magnus
 Originalmeddelande Från: Attila Kinali  
Datum: 2020-02-17  16:56  (GMT-06:00) Till: Discussion of precise time and 
frequency measurement  Ämne: [time-nuts] Pressure 
sensitivity of Rb vapor cell standards Moin,I'm currently going through some of 
my old stuff and stumbledover [1], which, I think, has not been mentioned here. 
ButI remember a few people talking about compensating the 5065for pressure 
sensitivity. I also recommend having a look at Nil's paper[2], which 
discussesthe placment of the whole cell in hermetically sealed box forpressure 
stability and notes that there is a residual barometricpressure shift related 
to temperature changes. The paper containsalso a lot of pointers of what to 
look for, for additional sourcesof instability in Rb vapor cells. Especially 
note that light shift,ie the frequency shift due to changes in light intensity 
are themajor source of instability (as noted in many other papers).            
Attila Kinali[1] "Barometric Effect in Vapor-Cell Atomic Clocks",by Moreno, 
Pellation, Affolderbach, Mileti, 
2018https://doi.org/10.1109/TUFFC.2018.2844020[2] "Long-Term Stability Analysis 
Toward <10−14 Level for a Highly CompactPOP Rb Cell Atomic Clock" by Almat, 
Gharavipour, Moreno, Guret,Affolderbach, Mileti, 
2020https://doi.org/10.1109/TUFFC.2019.2940903--     The bad part 
of Zurich is where the degenerates    throw DARK chocolate at 
you.___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Using a common power supply among few time standards

2020-02-08 Thread ew via time-nuts

Thank you for your warning. Have not bought Traco but was considered after 
Poul-Henning recommendation. Will stay with Mean Well have plenty good 
experience,  a couple % more efficiency was tempting no more         
Bert Kehren


In a message dated 2/8/2020 4:43:02 PM Eastern Standard Time, 
megaflu...@gmail.com writes:

Hi Bert,

Make sure to measure the noise on the Traco (on both input and output)
We had some issue with noise from a couple of Traco models at work. We
changed to Mean Well, and much less noise

Br,
Askild

On Sat, Feb 8, 2020 at 8:10 PM ew via time-nuts 
wrote:

> Just got this in the mail I am sure they have related items.
> We use with very good results Mean Well SD DC/DC products, for my Rb 8607
> project I plan on using Traco Power
>
> https://www.maximintegrated.com/en/design/reference-design-center/ref-circuits/7055.html?utm_source=Eloqua_medium=email_content=REFDES1234_campaign=FY20_Q3_2020_FEB_ALL-BU_AMER_EE-Mail_EN
> Bert Kehren
>
> In a message dated 2/8/2020 11:45:09 AM Eastern Standard Time,
> kd4...@gmail.com writes:
>
> Hi Taka,
>
> How about using the open frame linear supplies like the ones from Power
> One or Lambda?
> I usually pick these up when I find them, recap if needed and they're a
> cheap and easy way to get a supply.
>
> Chris
> KD4PBJ
>
> > On Feb 6, 2020, at 4:29 PM, Taka Kamiya via time-nuts <
> time-nuts@lists.febo.com> wrote:
> >
> > I have been addicted to home brewing GPSDO, Rubidium, OCXO, and etc,
> etc, etc.  I don't mean making of these from scratch but taking a surplus
> unit and encase them in ready-to-use form.  Most of them are in U2 rack
> case.
> >
> > One part of it that I really do not like is constructing a power supply
> for each and every unit I make.  Good power supplies are essential to clean
> and stable timebase, I know.  It is also heat generating as most of what I
> make use linear regulators.  But it's tedious and mandane to do it every
> single time!  So, I wanted to make a large enough power supply to provide
> +24V, +/- 12V, and 5V.  My plan was to have independent feed line for each
> timebase unit.
> > Is this even a good idea?  I have no experience in this to make a
> reasonable judgement.  This plan would mean these power voltages will be
> fed to each components without any local regulation.  While I do plan to
> put ferrite chokes and bypass capacitors at input, but since the whole
> point is to eliminate local power supply components, there will be nothing
> else in terms of isolation.
> > Similarly, I was also thinking of having a large battery bank for 24
> volt supply.  What type of battery is irrelevant and so as charging method
> for this question.  I have heard of this being done.  But for units that
> require 24 volts, that means there is no room for any type of regulation.
> Most 24V batteries output varying voltage depending on state of charging.
> I know 12V battery can produce as high as 13.x volt.  Is anyone doing this
> type of thing on this list?  If so, would you be willing to share details?
> >
> > Appreciate any input.
> >
> > ---
> > (Mr.) Taka Kamiya
> > KB4EMF / ex JF2DKG
> > ___
> > time-nuts mailing list -- time-nuts@lists.febo.com
> > To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Using a common power supply among few time standards

2020-02-08 Thread ew via time-nuts

Just got this in the mail I am sure they have related items.           
We use with very good results Mean Well SD DC/DC products, for my Rb 8607 
project I plan on using Traco Power
https://www.maximintegrated.com/en/design/reference-design-center/ref-circuits/7055.html?utm_source=Eloqua_medium=email_content=REFDES1234_campaign=FY20_Q3_2020_FEB_ALL-BU_AMER_EE-Mail_EN
Bert Kehren

In a message dated 2/8/2020 11:45:09 AM Eastern Standard Time, kd4...@gmail.com 
writes:

Hi Taka,

How about using the open frame linear supplies like the ones from Power One or 
Lambda?
I usually pick these up when I find them, recap if needed and they're a cheap 
and easy way to get a supply. 

Chris
KD4PBJ

> On Feb 6, 2020, at 4:29 PM, Taka Kamiya via time-nuts 
>  wrote:
> 
> I have been addicted to home brewing GPSDO, Rubidium, OCXO, and etc, etc, 
> etc.  I don't mean making of these from scratch but taking a surplus unit and 
> encase them in ready-to-use form.  Most of them are in U2 rack case.
> 
> One part of it that I really do not like is constructing a power supply for 
> each and every unit I make.  Good power supplies are essential to clean and 
> stable timebase, I know.  It is also heat generating as most of what I make 
> use linear regulators.  But it's tedious and mandane to do it every single 
> time!  So, I wanted to make a large enough power supply to provide +24V, +/- 
> 12V, and 5V.  My plan was to have independent feed line for each timebase 
> unit.
> Is this even a good idea?  I have no experience in this to make a reasonable 
> judgement.  This plan would mean these power voltages will be fed to each 
> components without any local regulation.  While I do plan to put ferrite 
> chokes and bypass capacitors at input, but since the whole point is to 
> eliminate local power supply components, there will be nothing else in terms 
> of isolation.
> Similarly, I was also thinking of having a large battery bank for 24 volt 
> supply.  What type of battery is irrelevant and so as charging method for 
> this question.  I have heard of this being done.  But for units that require 
> 24 volts, that means there is no room for any type of regulation.  Most 24V 
> batteries output varying voltage depending on state of charging.  I know 12V 
> battery can produce as high as 13.x volt.  Is anyone doing this type of thing 
> on this list?  If so, would you be willing to share details?
> 
> Appreciate any input.
> 
> --- 
> (Mr.) Taka Kamiya
> KB4EMF / ex JF2DKG
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Odd-order multiplication of CMOS-output OCXO

2020-01-19 Thread ew via time-nuts

The easiest way to do it is with an ICS 512 or ICS 570. We use the 570 all the
time
Bert Kehren
In a message dated 1/18/2020 7:34:00 PM Eastern Standard Time, m...@hau.nz
writes:

Hi time nuts,
I'm looking for a 5x frequency multiplication scheme to let me use a16-MHz
square-wave OCXO for an ADC encode clock at 80 MHz.
Constraints in order of importance:
1. Don't degrade the nice phase noise of the OCXO (-90 @ 1, -120 @10,-140 @
100, -160 @ 1k) any more than necessary; at the very least, itshould not impact
the ADC noise floor in the primary 0-40 MHz image.
(This should give quite a bit of leeway, but better is better :)
2. OCXO power consumption (~150 mW) should still dominate totalclock-system
power. Would like to keep the multiplier/buffer under 50 mW.
3. No supply rail above 3.3V.
This "ought to be" (?) easy, because the OCXO output is already rich inodd
harmonics. All that's needed is to isolate and perhaps buffer theright one
without screwing up my noise spec. This is where I could usesome help...
The ADC (AD9266) wants a differential clock, sinusoidal or squaredoesn't
matter. The datasheet recommends transformer coupling withantiparallel diodes
to keep the swing ~ 1.5Vp-p. (The min/max spec saysanything between 0.2 and
3.6V.) The 3.3V OCXO should give me 0.8Vp-pat the 5th harmonic without any
amplification, so in theory I guess Icould just filter and transformer couple
and be on my way. But perhapssome amplification is in order to increase the
slew rate?
I looked at the Wenzel tech notes for ideas, e.g. this one using logicgates and
tuned circuits:http://www.techlib.com/files/hcmos.pdfbut I lack the background
to evaluate the pros and cons of introducingextra CMOS logic.
I also found this common-base amp circuit in the
archives:https://www.febo.com/pipermail/time-nuts/2016-January/095683.html
andhttps://www.febo.com/pipermail/time-nuts/attachments/20160126/ae3b4be8/attachment-0001.pdf
I've read that I should avoid high-Q tuned circuits, because they willintroduce
more noise with temperature variation. Are there any rules ofthumb for how
much Q is too much?
Any pointers would be most appreciated!
Thanks,Mark

___time-nuts mailing list --
time-n...@lists.febo.comTo unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] HP5065A on ebay

2020-01-01 Thread ew via time-nuts

There is a HP5065A with date code 28 on ebay looks like new 12 hours to go

Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] John Fluke test equipment tutorial

2019-11-27 Thread ew via time-nuts

Looking through piles of manuals I found proceedings of frequency and time and 
frequency meetings I attended as part of my job, between 75 and 79. Each at 
least an inch thick. Is some one archiving the proceedings. Like them to find a 
home. Contact me off list

Bert Kehren


In a message dated 11/26/2019 8:39:37 PM Eastern Standard Time, 
paulsw...@gmail.com writes:

Azelio really just looking at what methods were used back then. That helps
me understand what I am looking at at a hamfest. Can I use it and how. I
have seen some very nice Gen Rad equipment at bargain prices. Unfortunately
I already had the same Z bridge. But it was a really tempting price and
unit was in mint condition.
But there are many bridges and dividers that show up at $20 or less.
So they just add to the test bench.
Regards
Paul.

On Tue, Nov 26, 2019 at 3:00 PM Azelio Boriani 
wrote:

> Indeed, and the 1980 edition might be the better choice if you're
> looking for circuits you can build.
>
> On Tue, Nov 26, 2019 at 6:00 PM paul swed  wrote:
> >
> > Azelio
> > A good point you make. From a slightly different perspective. The
> > technologies that are in the document show up at Hamfests around the east
> > coast of the US and with this book they make sense as to what they are
> and
> > how they are used. It also turns out that many of the devices have very
> > accurate resistors in them and somehow they have held tolerance over 60
> > years according to 5.5 digit HP meter.
> > Some of the devices are obvious in function others are not so clear. But
> > still a good read.
> > Regards
> > Paul
> >
> > On Tue, Nov 26, 2019 at 3:30 AM Azelio Boriani  >
> > wrote:
> >
> > > It is available here:
> > > 
> > > This is the first edition (1980) and is almost completely out of date
> > > regarding current metrology techniques. The time and frequency chapter
> > > (17) is only 5 pages long and dedicated to the time transfer using the
> > > Fluke VLF receiver/comparator. The second edition (1994) is a bit more
> > > theoretical.
> > >
> > > On Tue, Nov 26, 2019 at 2:43 AM paul swed  wrote:
> > > >
> > > > Perry kindly shared it with me a week or so ago. Its a really good
> read.
> > > > Enjoy and thanks Perry.
> > > > Regards
> > > > Paul
> > > >
> > > > On Mon, Nov 25, 2019 at 6:00 PM Perry Sandeen via time-nuts <
> > > > time-nuts@lists.febo.com> wrote:
> > > >
> > > > > Yo Bubba Dudes!,
> > > > > I've re-published the John Fluketutorial *Calibration Philosophy
> and
> > > > > Practice*  Circa 1980.
> > > > >
> > > > >  It describes how all the basicelectrical standards are derived and
> > > > > measured.  It is a 14 MbytePDF.  If anyone is interested in a copy
> > > please
> > > > > send me an *original* emailoff list for a copy
> > > > >
> > > > > Regards,
> > > > > Perrier
> > > > > ___
> > > > > time-nuts mailing list -- time-nuts@lists.febo.com
> > > > > To unsubscribe, go to
> > > > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > > > and follow the instructions there.
> > > > >
> > > > ___
> > > > time-nuts mailing list -- time-nuts@lists.febo.com
> > > > To unsubscribe, go to
> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > > and follow the instructions there.
> > >
> > > ___
> > > time-nuts mailing list -- time-nuts@lists.febo.com
> > > To unsubscribe, go to
> > > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > > and follow the instructions there.
> > >
> > ___
> > time-nuts mailing list -- time-nuts@lists.febo.com
> > To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Reverse Engineering FTS/Datum/Symmetricom 1050A or 1150A

2019-11-26 Thread ew via time-nuts

We are spending most of our time to find the best clean up loop, work includes 
EFOS 3 and 4. If would be nice if some one can share info on the 1050A we would 
duplicate and test

Thanks   Bert Kehren


In a message dated 11/25/2019 9:39:16 PM Eastern Standard Time, 
act...@hotmail.com writes:

Hi Jim;This may be best to go back to Time-Nuts for this.A properly working 
1050A is still one of the best Quartz Standards/Clean-Up Oscillators ever made 
and most likely will be for the foreseeable future making it well worth the 
effort of building extensive documentation - I for one would really enjoy 
contributing to that effort. Actually I think this logic could apply to a 
number of products.Now may be a good time if other Time-Nuts are interest in 
the same thing. A group of Time-Nuts could create a schematic of the basic 
design and the various revisions/options. Add photos, voltages, and signals at 
various test points, and how problems were resolved. I have found that most 
instruments have "The Usual Suspects" a few areas where in the unlikely event 
they have an issue it will often be the same part.  On the short term problem 
you are seeing I would test the 1000B out of circuit first and follow the 
signal path from there. Which options and what are the approximate build dates 
of yours.My main point is years ago there were third party companies like Sam 
Photo Fax offering tech and repair data on a wide range of electronics, and in 
this era where more and more companies are unwilling to share schematics and 
repair info we are seeing communities like the Time-Nuts, Volt-Nuts, and XDevs 
doing just that. Perhaps it is time to bring a more systemic and structured 
approach to that end. I would really enjoy being a part of such an 
effort.Cheers;
Tom Knox
SR Test and Measurement Engineer
Ascent Concepts and Technology
4475 Whitney Place
Boulder Colorado 80305
303-554-0307
act...@hotmail.com
"Peace is not the absence of violence, but the presence of Justice" Both MLK 
and Albert Einstein
From: AC0XU (Jim) 
Sent: Monday, November 25, 2019 4:26 PMTo: Tom Knox 
Subject: Re: [time-nuts] Service manuial for FTS 1050A or 
1150A
Tom-
Thanks for that. There is normal power in to the controller board and no power 
out. Shouldn't be too hard to track down, but the power board suprises me in 
its complexity. Was hoping to find a schematic...
BTW, I also have a few of these units. One works really well. Another has very 
poor short time stability.  I am guessing that there is something wrong with 
it, but do you have any ideas what could cause the behavior?
Jim

At 01:22 PM 11/25/2019, you wrote:Hi Jim;Let me know if you have any luck on 
the 1050A manual and I will do the same, I think the 1050A and 5071A are the 
holy Grail of service manuals. I have a couple 1050A's with issues. These are 
great cleanup oscillators, they often far exceed PN specs, I one better then 
128dB @ 1Hz which puts them up there with BVA's. The power board should not be 
to much trouble, If you need me to measure any voltages on a working 1050A let 
me know.Cheers;
Tom Knox
SR Test and Measurement Engineer
NIST/Ascent Concepts and Technology
4475 Whitney Place
Boulder Colorado 80305
303-554-0307
act...@hotmail.com"Peace is not the absence of violence, but the presence of 
Justice" Both MLK and Albert Einstein
From: time-nuts 
 on behalf of AC0XU (Jim) 
Sent: Sunday, November 24, 2019 9:55 AMTo: 
time-nuts@lists.febo.com Subject: [time-nuts] Service 
manuial for FTS 1050A or 1150A
Does anyone have a service manual for either FTS 1050A or 1150A (they are 
almost identical)? I have an 1150A with a bad power board
Thanks!
Jim

___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.___time-nuts 
mailing list -- time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Dead 5061B

2019-11-04 Thread ew via time-nuts

I would look at ionizer and Ionizer circuit. In the past I would see ion 
current increase when ionizer turned on.
Bert Kehren



In a message dated 11/3/2019 11:40:03 PM Eastern Standard Time, 
paulsw...@gmail.com writes:

Jim
Is there any hope. I would believe so. CS tubes are pretty tough. As Scott
says HV supplies but you measured those and they appear good as you say. So
its a knock down drag out battle. You have nothing to loose so dig in.
I wonder if the SRD may have popped. But its funny the ion pump is 0. That
seems a bit odd. always a bit of crud in the tube that should make that
kick up. My 10 cents.
Regards
Paul.

On Sun, Nov 3, 2019 at 3:45 PM Scott McGrath  wrote:

> Have you checked the HV supplies?
>
> Content by Scott
> Typos by Siri
>
> > On Nov 3, 2019, at 2:04 PM, AC0XU (Jim) 
> wrote:
> >
>
> Time Nuts-
>
> This 5061B was working fine until a recent power failure, after which the
> unit would not come on line (alarm light stayed lit).
>
> Major symptoms now:
>
> Beam I  ; Second Harmonic;  Ion Pump Supply are all 0 on front panel.  All
> other front panel readings are normal. (except for battery, which th unit
> doe snot have).
>
> L4P2 signal is 16.832 MHz 1.7 V p-p  (perfect - suggesting that A1
> synthesizer is fine)
>
> Going through 5-173 A12 Cesium Beam Tube Operational Checks:
>
> 5-175 Low Frequency Coil Check. Everything is fine except that tweaking
> the external oscillator frequence/amplitude has no effect. Beam I is always
> 0.
>
> The text says "If the beam current is not restored, it indicates a problem
> in the the cesium beam tube power supplies (A11, A15, A18, or A19) or in
> the cesium beam tube itself.
>
> A11 = Cesium Oven Controller - front panel reading is fine. Removed A11
> from the chassis and made the tests in  5-141.
> Everything fine. +- 16V and -10V all fine; Cs oven voltage fine; the
> thermistor tests out at 435 ohm vs. the 430 ohm on the label.
>
> A15 = Power Regulator Board - main +18.65V is fine
>
> A18 = +3.5KV supply - measured and is fine
>
> A19 = -2.5KV supply - measured and is fine
>
> I am inclined to conclude that the tube is dead. I don't understand why
> that occurred suddenly in conjunction with a line power failure.
>
> Can I have any hope that the tube is still o.k.?  Any ideas?
>
> Thanks!
>
> Jim
>
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Flash!!! FA2 works on Arduino Tablets !!!

2019-10-22 Thread ew via time-nuts

How does

https://www.startech.com/Cards-Adapters/Serial-Cards-Adapters/micro-usb-serial-adapter-android~ICUSBANDR232

do it? Once every thing else works I may buy one.
Bert Kehren

In a message dated 10/22/2019 9:06:15 AM Eastern Standard Time, 
shali...@gmail.com writes:

The tablet will not accept charging current when in the OTG mode, which is
required to make the tablet a master (USB is asymmetrical system, there is
always a master and a slave). It is not a function of the type of hub
plugged into it.
When you plug the tablet into a PC, the PC is the master and the tablet
will charge from the PC.
When you plug an accessory into the tablet, it becomes the master and it
delivers power to whatever is connected to it.

On Mon, Oct 21, 2019 at 9:06 AM Paul Moore  wrote:

> On Mon, Oct 21, 2019 at 12:01 AM Didier Juges  wrote:
> > One issue: once the tablet is connected to the FA2, there will be no way
> to
> > charge the tablet, so start with a fresh battery...
>
> I would think that if you connected both the FA2 and the tablet to a
> USB hub you should be able to talk to the FA2 as well as maintain the
> tablet's battery.  Of course this requires that you select a USB hub
> which can deliver enough power to the tablet, but that shouldn't be
> too difficult.
>
> --
> paul moore
> www.paul-moore.com
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Thank you Didier

2019-10-20 Thread ew via time-nuts

Thank you Didier. 

Some of us are serious time nuts that means our measurements exceed 24 hours.  
When GPS is involved 48 hours is a minimum. Unless you have a Cs fountain 
sooner or later you go back to GPS. Between Juerg and me we have at any time 4 
PC based computers running. Some tests go over weeks. Fan noise and power 
failure are only a few concerns.And along comes FA2 having two HP53132 no more 
concern about fan and display failure. That is why both of us immediately 
bought one and did extensive testing. Recommended to a few others off list Key 
part in our tool chest.A tablet makes it even better, plan on powering the 
tablet from the FA2. It is definitely not about money opens new opportunities 
and gets other time nuts involvedBert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Flash!!! FA2 works on Aderino Tablets !!!

2019-10-19 Thread ew via time-nuts

Thanks to Didier and his endless pations I have FA2 working on my $ 25   7 inch 
RCA tablet . If unlike me you know what you are doing it takes less than a 
minute

Bert Kehren
 http://www.ko4bb.com/Android/USBLogger_v002.apk 
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] FA2

2019-10-02 Thread ew via time-nuts

Attached is the corrected file of the data after the decimal.  The average is 
-8598.25  which is .91401 with the last 9 being -1 E-13.
Bert Kehren

In a message dated 10/2/2019 11:00:09 AM Eastern Standard Time, 
time-nuts@lists.febo.com writes:

Good Morning DidierThank you for your response. The "ONLY" thing we would like 
to do is record and display the info coming out of the RS post. To day making 
long term observations ties up a PC or Laptop with fans and a HP53132. Gone for 
a week the main concern is fan failure. Store the info on the Tablet in a SD 
chip or in it and when ready download through the USB port that we use for 
importing data to a memory stick for further processingThis counter is low 
power, no fan and has resolution that exceeded the ability of our sources. Not 
bad for a $120 device.We are presently experimenting using a ISC570 multiplier 
at 100 MHz and get 13 digits see attached  but the data out of the back is only 
12 digits reliable. Looking at averaging.13 digits frequency at 10 seconds even 
exceeds an 8607, only a saphire will do it.In the past we have run a few 570's 
at 200 MHz will try, that way we will be able to monitor the 5MHz output of a 
HP5065A with 5 E-14 resolution.To day running aging test we average a 24 hour 
run against GPS. Example HP5065A against Tbolt. We repeat the test in 20 days 
or a month..We also use a handy 10 psec. resolution long term monitor using a 2 
channel counter modification that Richard MCC did for us 7 years ago. The 
counter we use with dual mixer.
Bert Kehren

In a message dated 10/1/2019 11:05:03 PM Eastern Standard Time, 
shali...@gmail.com writes:

Bert,

FA-2 uses serial emulation over USB with an FTDI chip. As far as I know,
this is not supported under iOS. The best way to get serial data into an
iOS device appears to be through a WiFi module. In this case, you would
have to go from USB to WiFi, not very practical.

Android supports serial via USB and through Bluetooth serial profile, so
you have more options.
To connect the FA-2 to an Android tablet, the FTDI chip should make it very
easy.

However, I am not sure what you want to do with the data in an Android
tablet. Do you have software to process it? If so, it seems it would most
likely support serial. Looking through the Play Store, I did not see
anything timing-related but I did not spend much time looking.

What are you interested in displaying?

Didier KO4BB

On Sun, Sep 29, 2019 at 2:12 PM ew via time-nuts 
wrote:

> Didier FA2 is USBBert
> In a message dated 9/29/2019 12:02:51 PM Eastern Standard Time,
> shali...@gmail.com writes:
>
> Android tablets support serial com via USB. You need an adapter which
> should be easy to find (google Serial Adapter for Android). Of course you
> will need the right software at the tablet end to do what you need.
> IOs does not support serial com natively (at least did not when I checked a
> year or two ago) so you would need more hardware to get the data into an
> IOs device.
> What do you want to do with the data in a tablet?
> I write Android apps so I may be able to help if you need to capture the
> data in some format.
>
> Didier KO4BB
>
>
> On Sun, Sep 29, 2019, 6:25 AM ew via time-nuts 
> wrote:
>
> >
> >
> > We use Serial com to interface with a PC  It would be nice if some one
> > could find a way to transfer the data to a tablet.
> >
> > Thanks  Bert Kehren
> > ___
> > time-nuts mailing list -- time-nuts@lists.febo.com
> > To unsubscribe, go to
> > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> > and follow the instructions there.
> >
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions 
there.___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

FA-2_100MHz_Average.ods
Description: application/oleobject
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] FA2

2019-09-29 Thread ew via time-nuts

Didier FA2 is USBBert
In a message dated 9/29/2019 12:02:51 PM Eastern Standard Time, 
shali...@gmail.com writes:

Android tablets support serial com via USB. You need an adapter which
should be easy to find (google Serial Adapter for Android). Of course you
will need the right software at the tablet end to do what you need.
IOs does not support serial com natively (at least did not when I checked a
year or two ago) so you would need more hardware to get the data into an
IOs device.
What do you want to do with the data in a tablet?
I write Android apps so I may be able to help if you need to capture the
data in some format.

Didier KO4BB

On Sun, Sep 29, 2019, 6:25 AM ew via time-nuts 
wrote:

>
>
> We use Serial com to interface with a PC  It would be nice if some one
> could find a way to transfer the data to a tablet.
>
> Thanks  Bert Kehren
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] FA2

2019-09-29 Thread ew via time-nuts

DidierThank you for your response. I just  bought an additional 7 inch tablet, 
cheap, would like to use it as a readout and storage to transfer for further 
processing.Attached what we are get with Serial.com on a PC.

In a message dated 9/29/2019 12:02:51 PM Eastern Standard Time, 
shali...@gmail.com writes:

Android tablets support serial com via USB. You need an adapter which
should be easy to find (google Serial Adapter for Android). Of course you
will need the right software at the tablet end to do what you need.
IOs does not support serial com natively (at least did not when I checked a
year or two ago) so you would need more hardware to get the data into an
IOs device.
What do you want to do with the data in a tablet?
I write Android apps so I may be able to help if you need to capture the
data in some format.

Didier KO4BB


On Sun, Sep 29, 2019, 6:25 AM ew via time-nuts 
wrote:

>
>
> We use Serial com to interface with a PC  It would be nice if some one
> could find a way to transfer the data to a tablet.
>
> Thanks  Bert Kehren
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

*  F:000500.0
   F:000500.04877
   F:000500.09756
   F:000500.04391
   F:000500.01951
   F:000500.01463
   F:000500.10733
   F:000499.97561
   F:000500.00975
   F:000500.02439
   F:000500.04390
   F:000500.05853
   F:000500.03903
   F:000500.06829
   F:000500.06340
   F:000500.04390
   F:000500.09268
   F:000500.08780
   F:000500.03415
   F:000500.01951
   F:000500.02439
   F:000500.01463
   F:000500.02438
   F:000499.99511
   F:000500.03414
   F:000500.01463
   F:000500.09270
   F:000500.05853
   F:000500.01951
   F:000500.04877
   F:000500.03414
   F:000500.10243
   F:000500.04877
   F:000500.08292
   F:000500.02926
   F:000500.19473
   F:000500.02439
   F:000499.9
   F:000500.03415
   F:000500.06829
   F:000500.15123
   F:000500.05366
   F:000500.01951
   F:000500.03902
   F:000500.11708
   F:000500.04877
   F:000500.01463
   F:000500.05366
   F:000500.12684
   F:000499.98536
   F:000500.03902
   F:000500.13144
   F:000500.05366
   F:000500.15123
   F:000500.06342
   F:000500.03902
   F:000500.01952
   F:000500.20977
   F:000500.04391
   F:000500.01951
   F:000499.95122
   F:000500.06829
   F:000500.0
   F:000500.03414
   F:000500.01950
   F:000500.08780
   F:000500.03902
   F:000500.02927
   F:000500.00486
   F:000500.05853
   F:000500.13658
   F:000500.10243
   F:000500.03902
   F:000500.11219
   F:000500.04391
   F:000500.03903
   F:000500.04390
   F:000500.08292
   F:000500.09755
   F:000500.02927
   F:000500.01951
   F:000500.01951
   F:000500.01951
   F:000500.05854
   F:000500.04879
   F:000500.04878
   F:000500.07318
   F:000500.03902
   F:000500.03415
   F:000500.00487
   F:000500.03903
   F:000500.04389
   F:000500.05366
   F:000500.06830
   F:000500.01952
   F:000500.04878
   F:000499.98049
   F:000500.10731
   F:000499.99024
   F:000500.16587
   F:000500.02438
   F:000500.03414
   F:000500.04389
   F:000500.16585
   F:000500.01950
   F:000500.04389
   F:000500.01462
   F:000500.03902
   F:000500.02438
   F:000500.08276
   F:000500.05367
   F:000500.01951
   F:000500.18048
   F:000500.04877
   F:000500.03414
   F:000500.00973
   F:000500.02927
   F:000500.08781
   F:000500.04390
   F:000500.05365
   F:000500.07316
   F:000500.12197
   F:000500.01463
   F:000500.03415
   F:000500.01951
   F:000500.04390
   F:000500.06341
   F:000499.99512
   F:000500.06815
   F:000500.05842
   F:000500.00487
   F:000500.15609
   F:000500.

[time-nuts] FA2

2019-09-29 Thread ew via time-nuts



We use Serial com to interface with a PC  It would be nice if some one could 
find a way to transfer the data to a tablet.

Thanks   Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] FA2 counter

2019-09-26 Thread ew via time-nuts

Did receive FA2 counter today. Everything as promised, like the 10 second mode 
best.Use a Datum 2000 as source 10 MHz in the back 5 MHz in the front reliable 
+- 1 on the last 12th digit.


Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] 15Mhz in 10MHz out?

2019-09-18 Thread ew via time-nuts

One  dual D with an XOR gives you a 50% duty cycle
Bert Kehren
In a message dated 9/18/2019 10:09:43 AM Eastern Standard Time, 
bruce.griffi...@xtra.co.nz writes:

Dual JK flipflop configured as divide by 3 producing a 33% duty cycle 5MHz 
output which is filtered to extract the 10MHz second harmonic component.

Bruce
> On 18 September 2019 at 21:08 "David C. Partridge" 
>  wrote:
> 
> 
> Having seen the recent discussion of the NB3N502 and other PLLs for
> frequency multiplication.  I'm wondering if anyone knows of a similar
> *small* IC that will convert 15MHz to 10MHz ?
> 
> Why? My current modifications to the KS24361 output 10Mhz signals regardless
> of whether the unit has lock.  ISTR that the original 15MHz output was only
> enabled when the unit had lock.  I'd like to redo the PCB which I put in
> place of the 15MHz band-pass filter and replace it with one that takes 15Mhz
> an outputs 10Mhz.
> 
> Thanks
> David
> 
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] 5 Mhz to 10 Mhz and 25 Mhz

2019-09-09 Thread ew via time-nuts

PaulThe easiest way is one or two  ICS512 or ICS570B we use the 570 
extensively. Digi Key and ebay have both
Bert Kehren
In a message dated 9/8/2019 10:49:33 AM Eastern Standard Time, 
p...@bicknells.f2s.com writes:

Dear all

Can any one point me in the direction of a circuit that can convert 
5 Mhz signal to give me 2 outputs one at 10 Mhz and another at 25 Mhz


Regards Paul B


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] ADRAT 4110 Frequency difference multiplier

2019-09-07 Thread ew via time-nuts


As to availability the only ones II know, will ask Juerg if he knows of any 
others.  


In a message dated 9/7/2019 8:03:07 AM Eastern Standard Time, 
p...@bicknells.f2s.com writes:

Hi Bert
Thank you for you post 
Looking for a service manual in PDF format for the ADRAT 4110 if you ever
come across one 

Am I correct that Tracor 527 & ADRAT 4110 are the only Frequency difference
units available  ?

PS there is one of each available on  Ebay

Regards Paul 

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of ew
via time-nuts
Sent: 06 September 2019 20:10
To: time-nuts@lists.febo.com
Cc: ew
Subject: Re: [time-nuts] ADRAT 4110 Frequency difference multiplier

Juerg has two I have one love it also have Tracor 527 each. Same performance
Tracor also works at 10 MHz and has a meter, comes in handy.
Bert Kehren


In a message dated 9/6/2019 2:12:04 PM Eastern Standard Time,
p...@bicknells.f2s.com writes:

Dear all

Could any one let me have there experience with using the 
ADRAT 4110 Frequency difference multiplier

It dues the same as the  TRACOR 527 except it works 
On any of the following frequencies  1 , 2 , 2.5 , 5 , & 10 Mhz

Making it a very useful item in the Lab / work shop 

Also looking for a PDF of the Service manual 

Regards Paul  South Coast UK


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] ADRAT 4110 Frequency difference multiplier

2019-09-07 Thread ew via time-nuts

PaulYes ere is a 527 on ebay at one time they where more than 10K the 4110 
acording to Juerg was close to 20K Franken he had one in his Lab when he worked 
for a living probably 20 years ago.We will look if we have somewhere some 
info.We use these dayle, the fastest way to do do precise high resolution 
testing. I will check with Juerg I think we have AV data on both units that 
Juerg did.Bert
In a message dated 9/7/2019 8:03:07 AM Eastern Standard Time, 
p...@bicknells.f2s.com writes:

Hi Bert
Thank you for you post 
Looking for a service manual in PDF format for the ADRAT 4110 if you ever
come across one 

Am I correct that Tracor 527 & ADRAT 4110 are the only Frequency difference
units available  ?

PS there is one of each available on  Ebay

Regards Paul 

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of ew
via time-nuts
Sent: 06 September 2019 20:10
To: time-nuts@lists.febo.com
Cc: ew
Subject: Re: [time-nuts] ADRAT 4110 Frequency difference multiplier

Juerg has two I have one love it also have Tracor 527 each. Same performance
Tracor also works at 10 MHz and has a meter, comes in handy.
Bert Kehren


In a message dated 9/6/2019 2:12:04 PM Eastern Standard Time,
p...@bicknells.f2s.com writes:

Dear all

Could any one let me have there experience with using the 
ADRAT 4110 Frequency difference multiplier

It dues the same as the  TRACOR 527 except it works 
On any of the following frequencies  1 , 2 , 2.5 , 5 , & 10 Mhz

Making it a very useful item in the Lab / work shop 

Also looking for a PDF of the Service manual 

Regards Paul  South Coast UK


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] ADRAT 4110 Frequency difference multiplier

2019-09-06 Thread ew via time-nuts

Juerg has two I have one love it also have Tracor 527 each. Same performance 
Tracor also works at 10 MHz and has a meter, comes in handy.
Bert Kehren
In a message dated 9/6/2019 2:12:04 PM Eastern Standard Time, 
p...@bicknells.f2s.com writes:


Dear all

Could any one let me have there experience with using the 
ADRAT 4110 Frequency difference multiplier

It dues the same as the  TRACOR 527 except it works 
On any of the following frequencies  1 , 2 , 2.5 , 5 , & 10 Mhz

Making it a very useful item in the Lab / work shop 

Also looking for a PDF of the Service manual 

Regards Paul  South Coast UK


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] OCXO pressure sensitivity before TCXO

2019-08-05 Thread ew via time-nuts

Today most quality OCXO's are in a sealed can but three of the best HP10811, 
Austron 1150 and OSA 8600/07 are not sealed. Austroon set screw hole has a 
screw with an O ring. When you try to get the best out of them not part of a 
loop you may have to consider compensation like with Rb's. Maybe it is not the 
Xtal but some other part of the circuit. Any Idea or experience. Pressure will 
most likely be slow. Here in Florida Hurricane  is on us, maybe a time to 
outline a test.
Bert Kehren
In a message dated 8/5/2019 3:34:15 AM Eastern Standard Time, att...@kinali.ch 
writes:

On Sat, 3 Aug 2019 14:22:22 + (UTC)
ew via time-nuts  wrote:

> Are wee missing something. Reading Bill Slade post and old NASA
> attachments the attached plot to me was an eye opener. Our work 
> has always been focused on Rb pressure compensation. Are we
> overlooking something. Has any one done some work on this subject

No, we are not overlooking anything. Pressure sensitivity of
OCXOs has been long known and most manufacturers account for it
in their design. In most cases, the temperature induced instability
is larger than the pressure sensitive effect, together with the
pressure sensitivity measurement and characterisation being
expensive, it does not get mentioned in the datasheets.

But, if you really want to compensate for environmental effects,
then you need to have a quite complex model. This makes it rather
difficult to parametrize, you need measurements over months if not
years. That makes these parameters also quite difficult to use, as
they exhibit memory effects (e.g. hysterisis) and change over time.

If you are interested in this, have a look at the fields of 
"System identification." Or, if you want to have it a bit simpler
and more statistical: "Principal Component Analysis"

            Attila Kinali
-- 
    The bad part of Zurich is where the degenerates
                throw DARK chocolate at you.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] OCXO pressure sensitivity before TCXO

2019-08-03 Thread ew via time-nuts

Are wee missing something. Reading Bill Slade post and old NASA attachments the 
attached plot to me was an eye opener. Our work has always been focused on Rb 
pressure compensation. Are we overlooking something. Has any one done some work 
on this subject
Thanks    Bert Kehren

517.pdf
Description: Adobe PDF document
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Frequency Stability Analyzer - ZCDs

2019-07-27 Thread ew via time-nuts

In all our critical work we use the LTC6957,we call it the Bruce circuit, only 
problem at 78 and 80 difficult to solder
Bert Kehren


In a message dated 7/27/2019 4:04:50 AM Eastern Standard Time, 
bruce.griffi...@xtra.co.nz writes:

The LTC6957 is a better choice for squaring up sinewaves:
http://www.ko4bb.com/getsimple/index.php?id=phase-noise-and-other-measurements-with-a-timepod
CERN amongst others use it. The pin programmable filtering allows its bandwidth 
to be optimised to suit the input signal frequency and amplitude. This could be 
user selectable via front panel controls or under computer control.
Comparators are almost always noisier.
Oliver Collins wrote a paper on optimising such sine to square converters.
I extended the analysis to allow optimisation when the input noise of the 
cascaded stages arent equal.

Bruce
> On 27 July 2019 at 16:26 Glen English VK1XX  
> wrote:
> 
> 
> Hi
> 
> there is quite a bit done in this area of FPGAs, IDELAYS etc for this 
> application. and also quite a bit written already on TIMENUTS I find 
> from archives.
> 
>  From my POV, the pressure on the design is the input circuitry...My gut 
> is to start with a ADCMP572 and drive several FPGA pins  with PECL or 
> CML . BUT ! I have not thought about the problem very much, nor do I 
> have much experience with this application (and trying to be a little 
> modest here considering the company I am in) . The temperature 
> variability of the comparator hysteresis might be some issue with the 
> comparator.
> 
> I think the FPGA method certainly has many limits , compared to the 
> analog methods (dual slope phase comparators driving 24 bit ADCs etc, 
> vernier methods.) But my intuition is that a design that can leverage a 
> hybrid of analog  methods and some handy features available in modern 
> FPGAs can get the performance.
> 
> The idea is, to produce a general purpose high performance measurement 
> platform for HF region clocks, and pps, without having to resort to 
> buying an SR620.. analog front end, FPGA (VHDL) , drive for a standard 
> HD44780  LCD controller to display stuff, and  output (USB most likely) 
> for data analysis on a platform that has plenty of storage.
> 
> IDELAYS - there is good granuality (26ps Artix -1) (3 ps Ultrascale 
> Kintex)  , temperature stability is a bit average but that can be dealt 
> with. The IO delays are variable on the fly for some architectures. It 
> is not the whole story, but one of the bullets in the revolver in 
> acheiving the desired granuarity. There are several calibration options.
> 
> jitter added in the routing can be minimize with some manual placement 
> strategies
> 
> There  is an additional handle at the place and route level on 
> specifying constraint delays. This is pretty rough but if a good 
> calibration strategy can be developed, it is worthwhile. (IE conformance 
> to the constraint delays may vary from build to build so there needs to 
> be a bit of manual placement ) .
> 
> Yes, I think  trace delays are useful, although  rise time of the 
> devices together with PCB bandwidth muddies the water ,  and hence 
> uncertainty etc etc
> 
> I'd like to use a Lattice MACH X02 for this job but I think I will use a 
> Xilinx due to my familiarity  with them (and indeed, performance and 
> control of the synthesis tools) , and the speed.
> 
>     (i'm actually an RF person but FPGAs and DSP is an essential these 
> days) .
> 
> -glen
> 
> On 27/07/2019 11:49 AM, Hal Murray wrote:
> >> Was  considering  16 LVDS receivers and IDELAYS to emulate a single fast
> >> comparator,
> > I haven't done serious work with FPGAs in 10 or 15 years.
> >
> > That seems like an obvious hack, but it depends on the implementation 
> > details
> > inside the FPGA.  What's the granularity?  How much does it change from chip
> > to chip or over voltage and temperature?
> >
> > Has anybody published any data?
> >
> > --
> >
> > Another possibility is to use trace delays on the PCB.  You have a lumped
> > delay line with capacitance from the input pad.  This may not be practical 
> > for
> > short delays where the bond wires on the chip are not short relative to the
> > trace lengths.
> >
> >
> 
> 
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Advantages of GNSS ???

2019-07-09 Thread ew via time-nuts

RobertThat was my wrong take, since as long as I have messed with timing GPS 
receivers the difference was price and the fact that saw tooth data was present 
in hardware. Juerg did his first  M12/Dallas/Maxim in 2004 driving a PRS 10 
only replacing it when he bought a Tbolt through TARP.Working 10 years ago with 
Richard Mc Corkle his GPS MAX used also a PIC to read M12 data adding it up for 
the time constant and adding the sum to his filter calculation.
He also did a PIC for me using the D/M chip.Since something happened to Richard 
I set out to do a board to be used for our GPSDO.  Tests did not show ant 
improvements.
Did a Furuno board without saw tooth because it is only 4 nsec. Works great. In 
all cases the PIC also generated the survey command in order to work without a 
computer. The Furuno T does on power up an automatic survey. The N version also 
works great and is available at Berklin for 1/3 the price of T but does not 
survey. Only other one also with 1 pps. Looks like Berklin has a problem 
selling them, that why the price drop. All other ones more expensive.Bert Kehren

In a message dated 7/9/2019 11:05:39 AM Eastern Standard Time, 
lajeune...@mail.com writes:

Bert,

My take on the issue is that Mark Sims had not seen manufacturer documentation 
on how specifically to use the sawtooth correction value. You posted a picture 
of what we now know was an implementation of a use of the correction value. Did 
you have manufacturer documentation on how the value was to be used before you 
did your design? If so, that's what Mark is looking for. Like me, Dana was 
confused by your picture of a GPS assembly, which was not an answer to Mark. 
Knowing Dana personally I'm not surprised he started down the 20 question path, 
and I doubt he was actually offended by your post. 

respectfully,
Robert LaJeunesse

> Sent: Tuesday, July 09, 2019 at 6:26 AM
> From: "ew via time-nuts" 
> To: time-nuts@lists.febo.com
> Cc: ew 
> Subject: Re: [time-nuts] Advantages of GNSS ???
>
> Dana
> This was in response to Mark Sins " I don't think that I have ever seen what 
> to do  with the sawtooth value
>  documented in any receiver documentation"I did this 4 years ago it, is a 
> sawtooth corrected ublox.  First pass. Always do a follow on board but never 
> did any thing with it since there was no interest. We did it part of our 
> GPSDO work but saw no improvement. Sorry my work offends you.I did the same 
> with the Furuno GT and GN-87 without sawtooth since it is only 4 nsec. Ole 
> tested it and we use it with very good results. Again I followed it up with a 
> later design in case there is interest. I will not post the picture of the 
> original one so not to offend you.I will not do a board on the ublox 9 since 
> we are frequency not time nuts and see no need for it. 
> Bert Kehren
> 
> 
> In a message dated 7/9/2019 12:05:14 AM Eastern Standard Time, 
> k8yumdoo...@gmail.com writes:
> 
> One what?  I see that it is a Ublox unit, but see no reference to the
> interesting
> modern units like the 9 series.  Also, I note that the only reference on
> the board
> to "ant" is on the lower right corner, while what I suppose to be the
> actual antenna
> connector appears to be an SMA near the upper right corner.
> 
> And why does it look like several of the components have been resoldered
> or replaced or something?
> 
> Dana
> 
> 
> On Mon, Jul 8, 2019 at 8:00 PM ew via time-nuts 
> wrote:
> 
> > Well now you can see one
> > Bert Kehren
> >
> >
> > In a message dated 7/8/2019 7:02:07 PM Eastern Standard Time,
> > hol...@hotmail.com writes:
> >
> > A big issue with using the sawtooth correction message from a GPS
> > receivers is the issue of just what that sawtooth value is related to and
> > how to apply it to the measured PPS value / phase.
> > I added the ability to Lady Heather to calculate a sawtooth corrected
> > "paper clock" by applying the sawtooth correction message value to the PPS
> > output measured by an external counter like the TAPR TICC.
> >
> > There are around a dozen different combinations of sawtooth value and PPS
> > measurements...  only one of which minimizes the PPS error.  Do you add or
> > subtract the sawtooth value to the PPS measurement?  Do you apply the
> > sawtooth value to the previous/current/next PPS measurement?  Do you apply
> > the sawtooth correction to the PPS itself or the accumulated phase of the
> > PPS?
> > I don't think that I have ever seen what to do  with the sawtooth value
> > documented in any receiver documentation...  Heather has default receiver
> > dependent correction strategies or lets you specify the correction
> > strategy to use._

Re: [time-nuts] Advantages of GNSS ???

2019-07-09 Thread ew via time-nuts

Dana
This was in response to Mark Sins " I don't think that I have ever seen what to 
do  with the sawtooth value
 documented in any receiver documentation"I did this 4 years ago it, is a 
sawtooth corrected ublox.  First pass. Always do a follow on board but never 
did any thing with it since there was no interest. We did it part of our GPSDO 
work but saw no improvement. Sorry my work offends you.I did the same with the 
Furuno GT and GN-87 without sawtooth since it is only 4 nsec. Ole tested it and 
we use it with very good results. Again I followed it up with a later design in 
case there is interest. I will not post the picture of the original one so not 
to offend you.I will not do a board on the ublox 9 since we are frequency not 
time nuts and see no need for it. 
Bert Kehren

In a message dated 7/9/2019 12:05:14 AM Eastern Standard Time, 
k8yumdoo...@gmail.com writes:

One what?  I see that it is a Ublox unit, but see no reference to the
interesting
modern units like the 9 series.  Also, I note that the only reference on
the board
to "ant" is on the lower right corner, while what I suppose to be the
actual antenna
connector appears to be an SMA near the upper right corner.

And why does it look like several of the components have been resoldered
or replaced or something?

Dana

On Mon, Jul 8, 2019 at 8:00 PM ew via time-nuts 
wrote:

> Well now you can see one
> Bert Kehren
>
>
> In a message dated 7/8/2019 7:02:07 PM Eastern Standard Time,
> hol...@hotmail.com writes:
>
> A big issue with using the sawtooth correction message from a GPS
> receivers is the issue of just what that sawtooth value is related to and
> how to apply it to the measured PPS value / phase.
> I added the ability to Lady Heather to calculate a sawtooth corrected
> "paper clock" by applying the sawtooth correction message value to the PPS
> output measured by an external counter like the TAPR TICC.
>
> There are around a dozen different combinations of sawtooth value and PPS
> measurements...  only one of which minimizes the PPS error.  Do you add or
> subtract the sawtooth value to the PPS measurement?  Do you apply the
> sawtooth value to the previous/current/next PPS measurement?  Do you apply
> the sawtooth correction to the PPS itself or the accumulated phase of the
> PPS?
> I don't think that I have ever seen what to do  with the sawtooth value
> documented in any receiver documentation...  Heather has default receiver
> dependent correction strategies or lets you specify the correction
> strategy to use.___time-nuts
> mailing list -- time-n...@lists.febo.comTo unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow
> the instructions there.
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Advantages of GNSS ???

2019-07-08 Thread ew via time-nuts

Well now you can see one
Bert Kehren


In a message dated 7/8/2019 7:02:07 PM Eastern Standard Time, 
hol...@hotmail.com writes:

A big issue with using the sawtooth correction message from a GPS receivers is 
the issue of just what that sawtooth value is related to and how to apply it to 
the measured PPS value / phase.
I added the ability to Lady Heather to calculate a sawtooth corrected "paper 
clock" by applying the sawtooth correction message value to the PPS output 
measured by an external counter like the TAPR TICC.
 
There are around a dozen different combinations of sawtooth value and PPS 
measurements...  only one of which minimizes the PPS error.  Do you add or 
subtract the sawtooth value to the PPS measurement?  Do you apply the sawtooth 
value to the previous/current/next PPS measurement?  Do you apply the sawtooth 
correction to the PPS itself or the accumulated phase of the PPS?
I don't think that I have ever seen what to do  with the sawtooth value 
documented in any receiver documentation...  Heather has default receiver 
dependent correction strategies or lets you specify the correction  strategy to 
use.___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Overseas buying?

2019-07-04 Thread ew via time-nuts

 Just received 50 PCB's in 36 hours via DHL from Hong Kong and in the last 18 
Month two HP 5065A in less than 48 hours from Israel.      How ever shipping 
from the US   USPS is the best. 
Bert Kehren
In a message dated 7/4/2019 4:05:27 PM Eastern Standard Time, 
time-nuts@lists.febo.com writes:

Hello Jim,
I am in Germany and have sent several premium receivers (i.e. AEG Telefunken E 
1800/3 and Rockwell-Collins 851S-1) worlwide with DHL Express and German 
postal. No delay shipping to the US and no customs fees paid by the recipient.

If you need any help shipping from the EU let me know. BTW I get highly 
discounted rates (up to 67% below published rates for DHL Express and UPS) with 
a shipping broker in Germany
vy 73 Heinz DH2FA, KM5VT

dh...@me.com

Von meinem iPhone gesendet

> Am 04.07.2019 um 18:31 schrieb AC0XU (Jim) :
> 
> Anyone have suggestions about how to buy equipment from out of the country 
> without getting US Customs delays?  I have the impression that precision 
> timing devices are on some kind of US list of sensitive technologies, but 
> Customs seems to also be concerned about importing such items.
> 
> I recently purchased an Oscilloquartz OCXO from a seller in France and FEDEX 
> delayed delivering the item, requesting documentation about the item and 
> about the purchaser (me) over and over again. I found FEDEX's communications 
> to be atrocious - 7 different FEDEX people wanted me to email them 
> information, and they kept asking me to email documents to 
> paperw...@fedex.com, which bounced everything I sent it. For a few days, it 
> looked like FEDEX was going to return the package, because they kept 
> complaining that I wasn't responding to their requests for more information. 
> Emails to them bounced. My phone calls to them went unanswered. Eventually 
> FEDEX did release the package but it took over a week.
> 
> This was a frustrating experience and I am wondering what I should advise 
> sellers in the future about how to document items so as to get through US 
> Customs more smoothly. Any suggestions?
> 
> Thanks! 
> Jim
> 
> 
> ___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to 
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Overseas buying?

2019-07-04 Thread ew via time-nuts

USE DHLBert Kehren
In a message dated 7/4/2019 3:00:15 PM Eastern Standard Time, 
james.schatz...@ac0xu.com writes:

Anyone have suggestions about how to buy equipment from out of the country 
without getting US Customs delays?  I have the impression that precision timing 
devices are on some kind of US list of sensitive technologies, but Customs 
seems to also be concerned about importing such items.
I recently purchased an Oscilloquartz OCXO from a seller in France and FEDEX 
delayed delivering the item, requesting documentation about the item and about 
the purchaser (me) over and over again. I found FEDEX's communications to be 
atrocious - 7 different FEDEX people wanted me to email them information, and 
they kept asking me to email documents to paperw...@fedex.com, which bounced 
everything I sent it. For a few days, it looked like FEDEX was going to return 
the package, because they kept complaining that I wasn't responding to their 
requests for more information. Emails to them bounced. My phone calls to them 
went unanswered. Eventually FEDEX did release the package but it took over a 
week.
This was a frustrating experience and I am wondering what I should advise 
sellers in the future about how to document items so as to get through US 
Customs more smoothly. Any suggestions?
Thanks! Jim

___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] GPSDO 10MHZ Splitter

2019-06-21 Thread ew via time-nuts

There is a Trimbo GPSDO on ebay. We have a couple. 252162780444    look to me  
a later version of the Tbolt, has an additional board with Power and 
amplifiers. One 10 MHz is TTL and the other sine wave. Use the TTL for the 
counter.There is an other one on Auction, looks identical has two outputs but 
says Smmetricon may be cheaper 264367965036Bert Kehren

Seller assumes all responsibility for this listing.
In a message dated 6/21/2019 12:07:27 PM Eastern Standard Time, 
donmeadow...@gmail.com writes:

Is there an easy, and cheap way to add a splitter the 10Mhz signal from GPSDO, 
without going to a distribution amplifier tofeed two different devices?
I really don’t want to build a complicated project, or spend $200.00 dollars 
for an 8 output distribution ampoff the net.  One output would be dedicated for 
mycounter time base, and the other would be an ‘extra’ 10MHZ source for another 
counter, or just to display on the scope.
I don’t have a GPSDO yet, I just can’t decide on one.I am leaning to the 
Trimble, but it’s still undecided.
Could anyone comment on buying a “Refurbished by Seller”GPSDO on E-bay. They 
are a few dollars cheaper, but I reallywant one I can have trust and confidence 
in.
Sorry for the long post.Thanks, Don


Sent from Mail for Windows 10
___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Lars GPSDO

2019-04-05 Thread ew via time-nuts

I originally did it for Lars but the results are an eye opener and fits nicely 
in our GPSDO evaluations. A 24 hour test starts at 6 AM all my tests start at 
the same time. Hope to have a plot by 8 to morrow.Bert
In a message dated 4/4/2019 8:03:10 PM Eastern Standard Time, 
j99har...@gmail.com writes:

On Thu, Apr 4, 2019 at 5:00 PM paul swed  wrote:

> Bert
> Have to say I like the construction method. Guessing you shifted it to the
> middle picture.
> Can you please tell me what the middle box with the -12 counter is?
> Regards
> Paul
>
>
> Yes the GPSDO is built on a "Perma-Proto" board that mimics the layout of
those solderless prototype boards. I wanted everything on 0.1 in. centers
for easy soldering.

It was originally in the cardboard Samsung cellphone box at the left. Bert
suggested it might not survive shipping to Florida, so I moved it to the
plastic box with a clear cover. In addition to being sturdier, it lets you
see the blinking LEDs. while it is operating.

Thanks again to Bert for his kind testing assistance.
-- 

--Jim Harman
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Lars GPSDO

2019-04-04 Thread ew via time-nuts

It is an Adret multiplier like the Tracor 527 but in stead of meters has LED's 
we use both can read the LED's from 10 feet away but the meter of the Tracor 
shows short changes, that is how I found out the tbolt problem.Bert
In a message dated 4/4/2019 5:00:25 PM Eastern Standard Time, 
paulsw...@gmail.com writes:

Bert
Have to say I like the construction method. Guessing you shifted it to the
middle picture.
Can you please tell me what the middle box with the -12 counter is?
Regards
Paul

On Thu, Apr 4, 2019 at 4:00 PM ew via time-nuts 
wrote:

> Recently Lars GPSDO came up on time nuts. I was working with Lars but we
> focused on other subjects. Never got around to test one. So when Jim Harman
> mentioned it I contacted him off list and offered to test his unit. He send
> me a picture of his unit. Oh boy but a promises is a promises. Encouraged
> him to stabilize it for shipping. Got it in the mail today. See attached
> picture. Had it up and running in 5 minutes. 5 minutes later 1 E -10. 10
> minutes later 3 E-11. After an hour up and down in the E-12 range like all
> the other ones.Will let it stabilize for 48 hours and do a 24 hour plot
> like we have done on all our other GPSDO's to better understand frequency
> over time do to ionosphere. Mainly do to the delay of ublox F9.Jim can go
> in detail about his work with Lars
>
> Bert___
> time-nuts mailing list -- time-nuts@lists.febo.com
> To unsubscribe, go to
> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Your board off list

2019-03-11 Thread ew via time-nuts

David

We have a couple of your boards and repeatedly go back using them One thing for 
us all the music is at 5 MHz, result we have to multiply adding one more source 
for variance.5 and 1 MHz output are not important.
Is there a relative easy way to convert to 5 MHz.Thank youBert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Li Ion Battery for HP 5065A

2019-03-08 Thread ew via time-nuts

 A123 7Ah "brick" LiFePO4   who is the vendor?Bert Kehrren

In a message dated 3/8/2019 4:03:53 PM Eastern Standard Time, 
jim...@earthlink.net writes:

On 3/8/19 5:38 AM, Bob kb8tq wrote:
> Hi
> 
> If you are headed into a “cost is no object” sort of battery backup bank for 
> the lab / shelter / cave
> there are some interesting options out there. The RV world is very slowly 
> waking up to the fact that
> big heavy lead acid batteries may not be ideal. For a ghastly amount of 
> money, you can now get
> 12V 100AH “drop in” (no they are not drop in) Lithiums with fully integrated 
> BMS systems in them.
> They *appear* to be safe and come with cute things like 10 year warranties . 
> Be aware that you
> can buy a nice 5065 on eBay for what a couple of them will set you back …..
> 

I've used the A123 7Ah "brick" LiFePO4 that replace the standard Lead 
Acid - they weigh a LOT less, and cost a LOT more ($100 vs <$10) - 
They're pretty nifty devices.  As you note internal battery management, 
built in (easily replaceable) 30A fuse, etc.

They weigh about 850g (vs 2.6 kg) and work well at low temperatures (-20C)

One peculiarity is that if you discharge them below minimum voltage, 
they cutoff and put out nothing. You have to put a charging voltage on 
them to turn them back on.  This fouls up some "smart" battery chargers 
which use the "discharged" battery voltage to tell them that there's a 
battery connected.  So we always had our smart chargers for day to day 
use, but had a couple wall wart trickle chargers around to turn the 
battery back on.

100 Ah would set you back well over a kilobuck.  But, you would be able 
to lift it without you going over the OSHA 55lb/25kg "one person lift" 
limit.

> In return for your massive cash outlay, you get a battery that does not 
> outgas or have the need
> to be watered along with the plants. It has a much flatter discharge voltage 
> curve than a lead acid.
> Their peak current vs voltage generally is better than a lead acid. The BMS 
> may impact this if it
> is an issue in your setup. They also is a *lot* lighter / smaller for the 
> same amount of useful
> capacity. The built in BMS *should* take care of all of the fiddly little 
> issues that might burn the
> house down. Lots to like other than the absolutely giant hole in the wallet ….
> 
> Bob

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] Li Ion Battery for HP 5065A

2019-03-08 Thread ew via time-nuts

For my frequency stand alone setup opposite the rest of the lab I have a 100 A 
12V AGM/Inverter/Resonsnt Transformer that will power the setup for 10 hours, 
but like you I like remove the HP 5065A powered up. Did consider a similar 
system for the HP 5061B but have not and most likely will not touch it.I am 
concerned about fire but I have more than 10 in one form or the other Li Ion 
batteries in the house. The Battery is inside the frame that comes with the 
unit. Starting with a quality product, slow charging and dual max voltage 
control and dual low voltage shut out risk is very low. Changing the Zener in 
the 65 reduces the output from 33V to 29.5V. The 65 cut out of 21.5V is perfect 
for 7 batteries. Charging will be close to C/20.  Most problems out there seem 
to be do to over charge and temperature rise. Multiple tests will be done with 
the pack outside the unit to allow close monitoring.The main reason for my 
posting is the pile of junk batteries and finding a reliable source.in the US.
Bert Kehren
In a message dated 3/7/2019 8:24:09 PM Eastern Standard Time, jlt...@att.net 
writes:

Bert,

I'm interested in your quest.

I'm interested in batteries for not only the 5065A but also the 5061A and B.  I 
was thinking of an SLA for the 5061's.  I like the idea of being able to move 
the units without having to also move a separate battery backup system 
simultaneously.

What have you come up with and how have you addressed the potential for 
catastrophic failure of a Lithium Ion battery?

Hope all is well.

Joe

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@lists.febo.com] On Behalf Of ew via 
time-nuts
Sent: Thursday, March 07, 2019 3:37 PM
To: time-nuts@lists.febo.com
Cc: ew
Subject: [time-nuts] Li Ion Battery for HP 5065A



Having recently acquired a HP 5065A with clock I decided to put a battery in 
it. My choice is 5000 mA Lithium Ion. Having in the past very good experience 
with a Florida vendor, was first choice. Sadly he is going out of business. 
90+% out there is junk, have 26650s with 1800 mA. Last week finally located a 
reliable vendor, purchased seven 21700 Samsung B50s, reasonable price. 21700 is 
a better fit in the 50 X 65 X175 mm battery frame. After extensive dialog with 
vapah.inc and bench tests of all seven 4800 to 5200 mA, I am convinced that I 
found in the US a very viable source. No commercial or any other interest, now 
my only problem is how to get rid of the other junk.


Bert Kehren
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.


___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

[time-nuts] Li Ion Battery for HP 5065A

2019-03-07 Thread ew via time-nuts



Having recently acquired a HP 5065A with clock I decided to put a battery in 
it. My choice is 5000 mA Lithium Ion. Having in the past very good experience 
with a Florida vendor, was first choice. Sadly he is going out of business. 
90+% out there is junk, have 26650s with 1800 mA. Last week finally located a 
reliable vendor, purchased seven 21700 Samsung B50s, reasonable price. 21700 is 
a better fit in the 50 X 65 X175 mm battery frame. After extensive dialog with 
vapah.inc and bench tests of all seven 4800 to 5200 mA, I am convinced that I 
found in the US a very viable source. No commercial or any other interest, now 
my only problem is how to get rid of the other junk.

 
Bert Kehren 
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

Re: [time-nuts] FCC OTA pre-emption and restrictions on GPS antennas [was: Short term 10MHz source]

2019-01-04 Thread ew via time-nuts

Had in North Miami Beach that problems at some friends Condos. Used several 
times the sewer vent pipe every home seems to have. In one critical case 
(unfriendly neighbors) with flat roof cut the pipe off three inches from the 
roof used a coupling to the old cut off top pipe but drilled holes in it and 
inserted the attached. The young man got to enjoy Tbolt with LH. Mother liked 
it.Bert Kehren
In a message dated 1/4/2019 4:16:00 PM Eastern Standard Time, 
hol...@hotmail.com writes:

A friend of mine has his GPS antenna disguised as a bird feeder...  ground 
plane is a pizza pan.  Antenna mounted at the top of a clear tube filled with 
bird food... alas, no holes for the birds to get to the 
food.___time-nuts mailing list -- 
time-n...@lists.febo.comTo unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.comand follow the 
instructions there.
___
time-nuts mailing list -- time-nuts@lists.febo.com
To unsubscribe, go to 
http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com
and follow the instructions there.

1 2 >

1 - 100 of 119 matches

Mail list logo