[time-nuts] Zyfer Nanosync-380 GPSDO performance

[Mark Sims]

I ran a test of the Zyfer Nanosync-380 GPSDO 1PPS signal performance using a 
TAPR TICC.  The TICC was clocked by a HP-5370A.  The TICC was in time interval 
mode with the Zyfer 1PPS on channel A and the 5071A 1PPS on channel B.   

These numbers are sort of a worst case.  The Nanosync had been powered down for 
2 days after a couple of weeks of running.   The Zyfer was powered up until it 
started tracking satellites and had an almanac, then a self-survey (1 hour) was 
started.   After the survey completed the data acquisition was started.  At 
10,000 seconds the Nanosync ADEVs were in the mid E-13 range.  Values below tau 
around 30 seconds are probably better, but the TICC resolution is the limiting 
factor.

The blue plot is frequency deviation of the 1PPS (1Hz)  signal scaled to 10 MHz 
from a nominal.value of 10 MHz.  My TADD2-mini dividers were in use elsewhere, 
so I could not measure the actual 10 MHz output.

I'm running a similar test on the TruePosition GPSDO now...___
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[time-nuts] Fwd: Fwd: HP10811 Oscillator Thermal Fuse

[Donald E. Pauly]

https://www.febo.com/pipermail/time-nuts/2017-May/date.html

In order to have a runaway trophy, the thermal fuse would have to have
been jumpered and then an oven control failure would have to have
occurred.  The rated temperature of 125° C is well above operating
temperature of 82°C.  The thermal fuse can easily be soldered in by
heat sinking the leads where they enter the fuse.  The leads are
plenty long enough. I have done this dozens of times on Amana
microwave ovens in the late 70s. The venerable HP105 oscillator
contains a thermal fuse in both the fast warmup heater and the
proportional heater.

"3-8 Each heater circuit contains a thermal fuse to prevent damage to
components within the oven due to overheating."

I hadn't thought about smoking the styrofoam which melts at 240° C.
https://en.wikipedia.org/wiki/Polystyrene#Extruded_polystyrene_foam I
calculate that the oven could reach at least 208° C at the rated 71° C
ambient.Solder melts at 180° C.  Each power transistor has around
10 Volts across it and might even reach 300° C without destruction.
Many oscillators are operated above 20 Volts for the heater supply.
We have two reports of open thermistors in which disaster was avoided
by the thermal fuse blowing.


πθ°μΩω±√·Γλ
WB0KVV



-- Forwarded message --
From: Richard (Rick) Karlquist 
Date: Wed, May 10, 2017 at 5:34 PM
Subject: Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse
To: Discussion of precise time and frequency measurement 


The view from inside HP when I worked with the people
who designed and built the 10811 some 35-40 years ago
was that:

1.  10811 ovens rarely fail.

2.  When they do fail, it is rarely because the oven
runs away.  I know I have never encountered a runaway.
No one at HP had a "trophy" on their desk of a runaway
10811.  People tend to collect stuff like that.  One
engineer did have a 10811 with a 45 caliber bullet
fired through it (long story).

3.  From a business perspective, a failure is a failure
and so there is no business reason to have a fuse.

4.  Because the fuse could not be soldered in, it had
to be socketed, and the socket failures exceeded any
oven runaways by a good margin.  Therefore, it made
the "failure rate" worse.  That is all that matters to
the bean counters.

5.  The one and only reason it was in there at all
was the concern about toxic gases being released from
the foam.  Even without a runaway, foams tend to have
a "slow burn" and outgas "stuff" all the time.  Various
foams were evaluated to balance that issue with thermal
resistance and with the big issue with foam which is
mechanical fatigue.  This is similar to the wear out
of foam mattresses.

What should have been done with the thermal fuse would
have been to put crimp lugs on the leads and attach
the crimp lugs with screws.  However, there was no space
for all that stuff.

Rick N6RK
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Re: [time-nuts] current status of eLORAN globally

[paul swed]

You have it pretty much.
Regards
Paul

On Wed, May 10, 2017 at 8:43 PM, Ruslan Nabioullin 
wrote:

> Hi, what's the current status of eLORAN globally?  It's difficult to
> find the latest information on this on the WWW.  As I understand it,
> there currently exist only two active eLORAN projects, Ursanav/US
> gov't in the US, and Babcock Comms/UK gov't in the UK (and possibly
> South Korea as well?).  I know that the former has operated only one
> site in the near past (Wildwood), though the testing period (according
> to its website) has expired and I'm not seeing any information on a
> continuation.  As for the latter, as the recent thread has informed
> us, at least one site is active (albeit experiencing some technical
> issues), Anthorn.  In particular, more detailed information, analysis,
> and predictions on these efforts are sought.
>
> Thanks in advance,
> Ruslan
>
> --
> Ruslan Nabioullin
> Wittgenstein Laboratories
> rnabioul...@gmail.com
> (508) 523-8535
> 50 Louise Dr.
> Hollis, NH 03049
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Re: [time-nuts] Anthorn eLoran

[jks]

The European segment of the KiwiSDR network has a number of SDRs with good 100 
kHz reception.
There is even a crude Loran-C display of sorts (use the “extensions” menu).
http://sdr.hu/?q=kiwiSDR
A good example, Haparanda, Sweden:  
http://sm2byc.ddns.net:8073/?ext=loran

The great historical record is available with LoranView from Markus, DF6NM
Anthorn is the second and third columns from the left. Seems to be running at 
the moment.
http://www.df6nm.bplaced.net/LoranView/LoranGrabber.htm



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[time-nuts] current status of eLORAN globally

[Ruslan Nabioullin]

Hi, what's the current status of eLORAN globally?  It's difficult to
find the latest information on this on the WWW.  As I understand it,
there currently exist only two active eLORAN projects, Ursanav/US
gov't in the US, and Babcock Comms/UK gov't in the UK (and possibly
South Korea as well?).  I know that the former has operated only one
site in the near past (Wildwood), though the testing period (according
to its website) has expired and I'm not seeing any information on a
continuation.  As for the latter, as the recent thread has informed
us, at least one site is active (albeit experiencing some technical
issues), Anthorn.  In particular, more detailed information, analysis,
and predictions on these efforts are sought.

Thanks in advance,
Ruslan

-- 
Ruslan Nabioullin
Wittgenstein Laboratories
rnabioul...@gmail.com
(508) 523-8535
50 Louise Dr.
Hollis, NH 03049
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Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

[Richard (Rick) Karlquist]

The view from inside HP when I worked with the people
who designed and built the 10811 some 35-40 years ago
was that:

1.  10811 ovens rarely fail.

2.  When they do fail, it is rarely because the oven
runs away.  I know I have never encountered a runaway.
No one at HP had a "trophy" on their desk of a runaway
10811.  People tend to collect stuff like that.  One
engineer did have a 10811 with a 45 caliber bullet
fired through it (long story).

3.  From a business perspective, a failure is a failure
and so there is no business reason to have a fuse.

4.  Because the fuse could not be soldered in, it had
to be socketed, and the socket failures exceeded any
oven runaways by a good margin.  Therefore, it made
the "failure rate" worse.  That is all that matters to
the bean counters.

5.  The one and only reason it was in there at all
was the concern about toxic gases being released from
the foam.  Even without a runaway, foams tend to have
a "slow burn" and outgas "stuff" all the time.  Various
foams were evaluated to balance that issue with thermal
resistance and with the big issue with foam which is
mechanical fatigue.  This is similar to the wear out
of foam mattresses.

What should have been done with the thermal fuse would
have been to put crimp lugs on the leads and attach
the crimp lugs with screws.  However, there was no space
for all that stuff.

Rick N6RK


On 5/10/2017 4:43 PM, Dan Rae wrote:

As I reported the last time this subject came up, or maybe the time
before, the only time I had an open thermal fuse was in a 10811 that had
an open thermistor.  I was able to replace that and get the OCXO
working, but if the fuse had been replaced with a wire link I'm sure the
entire oven would have been toast.

There have been two types of fuse fitted, all I those have are the type
that can be fitted with the plug in axial panasonic type, less than a
dollar from Digikey.  The older ovens had a different type but I imagine
it's similarly easy to replace.

All my 10811s have the higher temperature Panasonic fuse fitted and I
sleep well at night...

Dan
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Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

[Dan Rae]

As I reported the last time this subject came up, or maybe the time 
before, the only time I had an open thermal fuse was in a 10811 that had 
an open thermistor.  I was able to replace that and get the OCXO 
working, but if the fuse had been replaced with a wire link I'm sure the 
entire oven would have been toast.


There have been two types of fuse fitted, all I those have are the type 
that can be fitted with the plug in axial panasonic type, less than a 
dollar from Digikey.  The older ovens had a different type but I imagine 
it's similarly easy to replace.


All my 10811s have the higher temperature Panasonic fuse fitted and I 
sleep well at night...


Dan
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Re: [time-nuts] Anthorn eLoran

[Peter Vince]

Hi Alan,

 I get the impression there is a new project under development to make
it a commercial operation - see:

http://www.taviga.com/

 Peter
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[time-nuts] A good GPS-Receiver with 1PPS output...

[Mark Sims]

The GPS with the lowest PPS jitter/sawtooth is the Venus timing receiver... 
around 6 ns.   Nick Sayer sells one on Tindie for $50.  It is mounted on a 
board that has the same pinouts as the Adafruit Ultimate GPS.  Also Navspark 
sells one for more $.   

Lady Heather talks to the Venus receivers.
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Re: [time-nuts] Anthorn eLoran

[paul swed]

Its been quite the interesting read. I agree with the behavior of an
antenna issue. They should just use a larger penny. That tends to work for
a bit of time.
I suspect the reason to keep it going though is to test eloran's time
dissemination. The other sites are not needed for this purpose. In the US
there is only one site and they fake out a second site with a delay so that
the austrons and other receivers are happy. And it works. When the sites up
its great to see the receivers all locked.
No navigation though.

However there have been some comments made by pretty smart people that I
actually may believe that even with 1 site its possible to navigate. Please
don't throw stones. But given the quality of a local Rb references today
might it be possible?
The new eLoran gives about a 10 X and more frequency/time accuracy.
OK I am in very dangerous waters here. I hope I don't run onto the shoals.
Humor intended.
Reagrds
Paul
WB8TSL



On Wed, May 10, 2017 at 4:22 PM, Alan Melia 
wrote:

> Hi Peter
> Ah that sounds more like it. Aerial maintenaance shuts down the whole site
> these dats including MSF.  There is really no reason for them to keep it
> running but I think Trinity House are paying the bill. It cannot be used
> for nav without Lessay and the output from Sylt, So I muse that they are
> keeping it powered up because the equipment is quite old now (1990s
> vintage, the unused kit destined for Loop Head in Ireland) and if the leave
> it off for any length of time it just wont start again :-))  We all know
> that syndrome !
>
> I dont know if this is correct but I got the feeling it was not running
> anything like full power??
>
> Alan
> G3NYK
>
> - Original Message - From: "Peter Vince"  >
> To: "Discussion of precise time and frequency measurement" <
> time-nuts@febo.com>
> Sent: Wednesday, May 10, 2017 4:38 PM
> Subject: Re: [time-nuts] Anthorn eLoran
>
>
> I gather there is an intermittent fault that is taking out a fuse, which
>> they are, necessarily, working hard to rectify.
>>
>> Peter
>>
>>
>> On 10 May 2017 at 10:58, Iain Young  wrote:
>>
>> On 09/05/17 20:28, moGandalfG8--- via time-nuts wrote:
>>>
>>> Iain Young wrote:
 I now have all four with green tracking lights, so  looks good to go

 Thanks Iain,

 Also looking good here now so seems like I cried wolf after all,
 although
 very happy it wasn't anything more permanent:-)


 I noted this morning, mine were all "Red" again. This very much suggests
>>> antenna maintenance (Off while they work on it during the day, and on
>>> once they've finished the day's work before starting work on it again the
>>> next morning, rather like they do with MSF next door)
>>>
>>>
>>> Iain
>>>
>>>
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>>>
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>>
>
> ___
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Re: [time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

[Bob kb8tq]

 Hi

Unless you believe that HP’s quality was poor, the experience of the rest of 
the OCXO
business is likely relevant. In `~50 years of designing OCXO’s the only one I 
have ever
seen are the HP units. Nobody else does that. Based on return rates, the number 
of 
“runaway ovens” is negligible over a 30 year period. The is related to safety 
(full time 
power on). As it worked out, the fuse did not help them in that respect. The 
Fed’s still
ruled the gear had to be shut off at night.

Bob


> On May 10, 2017, at 5:34 PM, Donald E. Pauly  wrote:
> 
> https://www.febo.com/pipermail/time-nuts/2017-May/date.html
> 
> The poster at 
> http://www.simonsdialogs.com/2016/09/a-thermal-fuse-and-hp-10811-60111-repair/
> reported that the thermal fuse saved an oscillator from destruction
> when a thermistor opened.  HP made thousands of these which sold for
> $800.  If a large portion failed it would have been addressed.  They
> raised the temperature of the thermal fuse to reduce nuisance blows.
> I say that nuisance blows equal to real blows are worth the trouble.
> You may be getting oscillators on the surplus market or eBay which
> have a higher proportion of nuisance blows.
> 
> πθ°μΩω±√·Γλ
> WB0KVV
> 
> From: Mike Feher 
> Date: Tue, May 9, 2017 at 9:10 PM
> Subject: Re: [time-nuts] Fwd:  HP10811 Oscillator Thermal Fuse
> To: Discussion of precise time and frequency measurement 
> 
> Respectfully I disagree. I have totally shorted out numerous
> oscillator’s fuses with no problems. The design of those thermal fuses
> makes them vulnerable to opening just due to years of use without
> problem, in any of the electronics. My shorted out oscillators still
> work. Ideally, if handy, it is easy enough to replace them if one is
> available. They just plug in. If there is a thermal runaway, that
> caused the opening, to me that implies that there are other issues.
> Regards – Mike
> 
> Mike B. Feher, N4FS
> 
> 89 Arnold Blvd.
> 
> Howell, NJ, 07731
> 
> 848-245-9115
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[time-nuts] Fwd: HP10811 Oscillator Thermal Fuse

[Donald E. Pauly]

https://www.febo.com/pipermail/time-nuts/2017-May/date.html

The poster at 
http://www.simonsdialogs.com/2016/09/a-thermal-fuse-and-hp-10811-60111-repair/
reported that the thermal fuse saved an oscillator from destruction
when a thermistor opened.  HP made thousands of these which sold for
$800.  If a large portion failed it would have been addressed.  They
raised the temperature of the thermal fuse to reduce nuisance blows.
I say that nuisance blows equal to real blows are worth the trouble.
You may be getting oscillators on the surplus market or eBay which
have a higher proportion of nuisance blows.

πθ°μΩω±√·Γλ
WB0KVV

From: Mike Feher 
Date: Tue, May 9, 2017 at 9:10 PM
Subject: Re: [time-nuts] Fwd:  HP10811 Oscillator Thermal Fuse
To: Discussion of precise time and frequency measurement 

Respectfully I disagree. I have totally shorted out numerous
oscillator’s fuses with no problems. The design of those thermal fuses
makes them vulnerable to opening just due to years of use without
problem, in any of the electronics. My shorted out oscillators still
work. Ideally, if handy, it is easy enough to replace them if one is
available. They just plug in. If there is a thermal runaway, that
caused the opening, to me that implies that there are other issues.
Regards – Mike

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell, NJ, 07731

848-245-9115
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[time-nuts] Anyone using UBLOX LEA-M8F for GPSDO?

[Neil Smith G4DBN]

I’ve just ordered an LEA-M8F board from CSG to save time and trouble making a 
PCB. I am intending to use it to discipline one of my 100MHz OCXOs, using a /5 
divider.  Has anyone on the list used this chip to discipline an external OCXO? 
Any experiences to share and suggestions to get best performance?  I have two 
100MHz OCXOs, one is locked to a G3RUH 10MHz GPSDO, the other to an Rb source.  
I use them to lock local oscillators for SHF transverters. I’ll be using this 
when out in the field with SHF sources up to 241GHz, so I don’t have to move 
the Rb source around.

No particular reason for choosing the LEA-M8F other than it looks interesting 
to play with. Actually, who needs a better reason!
Neil
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Re: [time-nuts] Anthorn eLoran

[Alan Melia]

Hi Peter
Ah that sounds more like it. Aerial maintenaance shuts down the whole site 
these dats including MSF.  There is really no reason for them to keep it 
running but I think Trinity House are paying the bill. It cannot be used for 
nav without Lessay and the output from Sylt, So I muse that they are keeping 
it powered up because the equipment is quite old now (1990s vintage, the 
unused kit destined for Loop Head in Ireland) and if the leave it off for 
any length of time it just wont start again :-))  We all know that syndrome 
!


I dont know if this is correct but I got the feeling it was not running 
anything like full power??


Alan
G3NYK

- Original Message - 
From: "Peter Vince" 
To: "Discussion of precise time and frequency measurement" 


Sent: Wednesday, May 10, 2017 4:38 PM
Subject: Re: [time-nuts] Anthorn eLoran



I gather there is an intermittent fault that is taking out a fuse, which
they are, necessarily, working hard to rectify.

Peter


On 10 May 2017 at 10:58, Iain Young  wrote:


On 09/05/17 20:28, moGandalfG8--- via time-nuts wrote:


Iain Young wrote:
I now have all four with green tracking lights, so  looks good to go

Thanks Iain,

Also looking good here now so seems like I cried wolf after all, 
although

very happy it wasn't anything more permanent:-)



I noted this morning, mine were all "Red" again. This very much suggests
antenna maintenance (Off while they work on it during the day, and on
once they've finished the day's work before starting work on it again the
next morning, rather like they do with MSF next door)


Iain


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Re: [time-nuts] Sorry for the unedited post: Counter Internal Oscillator Importance with ExternalReference?

[Magnus Danielson]

Hi Thomas,

On 05/10/2017 07:12 PM, Tom Knox wrote:


Hi All;

I used my speech recognition software last night and reading my post
this morning I was embarrassed.  Hopefully this email will make
sense. Thanks everyone for their input. Tom, i have a question; was
there any difference between the two 53230A oscillators when locked
to an external reference? I have also experienced poor results with
my 53230A HS phase locked to an external reference. My issue is
constant pop-ups showing reference errors. I wonder if that is
related to issues you encountered. I would like to compare oscillator
options in the same counter model and I have several each  53230A's
and MCA3027's but sadly they have the same oscillator option in each
respectively so I cannot directly compare PLL oscillator
performance.


I won't comment on the 53230A's as I haven't dug into them (yet).


My thinking is a phase locked internal reference may not be the best
option for those of us with ULPN, Ultra Stable house references so I
am trying to reverse engineer the Tektronix FCA/MCA counter to
determine if there is away to directly feed an external reference
instead of phase locking the internal reference. My plan is to find a
way (if possible and it is encouraging) to do this while kee ping the
rest of the functionality intact, Which does appear possible on the
Tektronix, Fluke, Pendulum instruments (All the same base units
branded differently). It appears depending on the oscillator option
U11B sends an off/on signals to switch between internal oscillator
options; Std Pin3, Oven Pin5, or Rubidium Pin4. This switching then
has the installed reference option provides 10MHz signals to  U11B
pin204 RB, Pin205 Std, Pin206 Oven respectively, most likely changing
PLL parameters at the same time. Whether this is auto sensed or
manually controlled  I have yet to determine. The selection may be in
the menu. My thinking is this may allow simply adding a connector and
cable to the rear panel to apply an external reference directly.  In
these counters U9A seems related to the PLL functions including
control, sensing, and switching using the standard External Reference
input. If my idea pans out this feature would remain unchanged so the
internal oscillator can still be used ( When the direct feed is not
appropriate) to clean up a dirtier external reference. My plan is
(Unless someone else has already looked into this is to next see if
the same is also possible with the 53230A. The BIG question does this
improve performance. Any thoughts? I spoke with a friend Fred Walls
today and asked if he though the internal reference was much of a
factor when Lock to a good external reference and he did not thin so.
So I will keep anyone interested informed with my progress since I am
sure many of you have reference that may benefit from this
modification if it does improve performance.


Now, there is a PLL in the CNT-90/91 (Fluke IDs are PM6690/6691 and 
Tektronix IDs are FCA-3000/3100) and that is to lock the 100 MHz 
oscillator to whatever 10 MHz reference you got muxed in. The PLL chip 
is U9A which is an ADF4001 and the 100 MHz oscillator is around U47A, 
L3, C171, C177-C180 and D23. You need this setup, so you cannot bypass.


The FPGA does not to anything magic, there is first a mux to select 
whatever internal 10 MHz reference there is, according to option. Then, 
if it has external 10 MHz selected, it then selects that and outputs.


The ADF4001 is used as a phase-comparator and needed divide by 10 to 
compare things. The Charge-Pump output has the traditional capacitor and 
capitor/resistor chain, so there is your PI control-loop, which is 
exactly what you would like to see there. It would track in due to first 
degree thermal shift and I'd expect it to be sufficiently high bandwidth 
not to cause any concern of interest.


The external clock input includes a crystal filter, which helps to shave 
of disturbing sidebands.


I'm skeptical that there is much gain to be found in modifying that.
I know other designs have had problems, but I don't see that this one 
should have any major reasons for concern. I could do some measures once 
I'm back home.


If you have high-quality, low jitter/phase-noise 100 MHz, then you could 
feed that into the counter too, but it may need the 10 MHz for some 
things, I haven't checked all details yet to rule it out.

Still, I wonder if it is worth the trouble.

The designers knew where their main problems where, and this never 
popped up as a big concern for them.




Thanks again for everyone's input.


Thanks for keeping us out of trouble. :)

Cheers,
Magnus
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[time-nuts] Sorry for the unedited post: Counter Internal Oscillator Importance with ExternalReference?

[Tom Knox]

Hi All;

I used my speech recognition software last night and reading my post this 
morning I was embarrassed.  Hopefully this email will make sense.
Thanks everyone for their input. Tom, i have a question; was there any 
difference between the two 53230A oscillators when locked to an external 
reference? I have also experienced poor results with my 53230A HS phase locked 
to an external reference. My issue is constant pop-ups showing reference 
errors. I wonder if that is related to issues you encountered. I would like to 
compare oscillator options in the same counter model and I have several each  
53230A's and MCA3027's but sadly they have the same oscillator option in each 
respectively so I cannot directly compare PLL oscillator performance. My 
thinking is a phase locked internal reference may not be the best option for 
those of us with ULPN, Ultra Stable house references so I am trying to reverse 
engineer the Tektronix FCA/MCA counter to determine if there is away to 
directly feed an external reference instead of phase locking the internal 
reference. My plan is to find a way (if possible and it is encouraging) to do 
this while kee
 ping the rest of the functionality intact, Which does appear possible on the 
Tektronix, Fluke, Pendulum instruments (All the same base units branded 
differently). It appears depending on the oscillator option U11B sends an 
off/on signals to switch between internal oscillator options; Std Pin3, Oven 
Pin5, or Rubidium Pin4. This switching then has the installed reference option 
provides 10MHz signals to  U11B pin204 RB, Pin205 Std, Pin206 Oven 
respectively, most likely changing PLL parameters at the same time. Whether 
this is auto sensed or manually controlled  I have yet to determine. The 
selection may be in the menu. My thinking is this may allow simply adding a 
connector and cable to the rear panel to apply an external reference directly.  
In these counters U9A seems related to the PLL functions including control, 
sensing, and switching using the standard External Reference input. If my idea 
pans out this feature would remain unchanged so the internal oscillator can 
still be used (
 When the direct feed is not appropriate) to clean up a dirtier external 
reference. My plan is (Unless someone else has already looked into this is to 
next see if the same is also possible with the 53230A. The BIG question does 
this improve performance. Any thoughts? I spoke with a friend Fred Walls today 
and asked if he though the internal reference was much of a factor when Lock to 
a good external reference and he did not thin so. So I will keep anyone 
interested informed with my progress since I am sure many of you have reference 
that may benefit from this modification if it does improve performance.

Thanks again for everyone's input.

Thomas Knox


From: time-nuts  on behalf of Tom Van Baak 

Sent: Tuesday, May 9, 2017 9:03 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Counter Internal Oscillator Importance with 
ExternalReference?

Hi Thomas,

About the 53230A -- like many of us I figured there was no point in buying the 
expensive OCXO versions since I have plenty of good 10 MHz references around 
here. So years ago Keysight loaned me two of them for a month: one with, and 
one without OCXO. Like most counters, the 53230A has an ext-ref input. But it 
is horrible. And the ref output is even worse. I think we've discussed this on 
the list before, including ADEV and PN plots. I decided not to buy one, ever, 
until they fixed the problem.

So it could be a nice counter. Someone at Agilent / Keysight needs to re-design 
the int/ext/mux/pll clock handling of the 53230A; someone who understands phase 
noise and short-term stability; someone who honors the intent of ext-ref-in and 
ref-out; someone who keeps stupid microprocessor / LCD / comms / power supply 
noise out of the clock path. Meanwhile I keep my old 53132A's and older SR620's 
and stay away from the 53230A.

If you have your own measurements, please share. Maybe I just got a bad sample, 
I don't know. But the ext-ref performance smelled like poor engineering to me. 
My hope is that someone on the list will hack a 53230A, fix the problem, and 
share the solution with us, or even with Keysight.

/tvb


> Hi All;
>
> How important is the standard, medium, or high stability reference in 
> counters like the 53230A, or FCA3120 when locked to an ultra low phase noise 
> external reference? Particularly when making measurements and adjustments on 
> other ultra high performance references?
>
> I know Agilent sold 53132A counters with an option (H01 I believe) that 
> bypassed the internal reference completely when and external reference is 
> applied, but I think standard configuration on most counter is to discipline 
> the internal reference.
>
> Thanks for your thoughts.
>
> Thomas Knox

[time-nuts] Any time-nuts in New York want to do dinner tonight?

[Magnus Danielson]

Fellow time-nuts,

I seem to have a spare evening here in New York.
Anyone interested to meet up for dinner this evening?

I have my hotel near Times Square and can walk a bit, but I prefer to 
stay on Manhattan.


Contact me off-list if you are interested.

Cheers,
Magnus
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Re: [time-nuts] Anthorn eLoran

[Peter Vince]

I gather there is an intermittent fault that is taking out a fuse, which
they are, necessarily, working hard to rectify.

Peter


On 10 May 2017 at 10:58, Iain Young  wrote:

> On 09/05/17 20:28, moGandalfG8--- via time-nuts wrote:
>
>> Iain Young wrote:
>> I now have all four with green tracking lights, so  looks good to go
>>
>> Thanks Iain,
>>
>> Also looking good here now so seems like I cried wolf after all,  although
>> very happy it wasn't anything more permanent:-)
>>
>>
> I noted this morning, mine were all "Red" again. This very much suggests
> antenna maintenance (Off while they work on it during the day, and on
> once they've finished the day's work before starting work on it again the
> next morning, rather like they do with MSF next door)
>
>
> Iain
>
>
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> ailman/listinfo/time-nuts
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>
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[time-nuts] TruePosition GPS Receiver

[Mark Sims]

Some of the pins could be the Furuno GPS receiver data stream and not the GPSDO 
data stream.
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Re: [time-nuts] Anthorn eLoran

[David J Taylor]

Subject: Re: [time-nuts] Anthorn eLoran

Is there software available to receive these signals using an SDR device 
such as the RSP-1 or 2, AirSpy with SpyVerter, or whatever?  I don't have a 
dedicated receiver but it might be fun to see something, being not very far 
away from Anthorn.


Thanks,
David
--
SatSignal Software - Quality software written to your requirements
Web: http://www.satsignal.eu
Email: david-tay...@blueyonder.co.uk
Twitter: @gm8arv 


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Re: [time-nuts] Anthorn eLoran

[GandalfG8--- via time-nuts]

Yes, noticed here it was off again and am pretty sure you're right about  
maintenance, just don't remember them starting at 0700 in the past:-)
 
Nigel, GM8PZR
 
 
In a message dated 10/05/2017 10:58:31 GMT Summer Time, i...@g7iii.net  
writes:

On  09/05/17 20:28, moGandalfG8--- via time-nuts wrote:
> Iain Young  wrote:
> I now have all four with green tracking lights, so  looks  good to go
>
> Thanks Iain,
>
> Also looking good here  now so seems like I cried wolf after all,  
although
> very happy it  wasn't anything more permanent:-)
>

I noted this morning, mine  were all "Red" again. This very much suggests
antenna maintenance (Off  while they work on it during the day, and on
once they've finished the  day's work before starting work on it again 
the next morning, rather like  they do with MSF next  door)


Iain


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Re: [time-nuts] First batch data of China pulstar observation satellite

[Li Ang]

Hi
The readme.txt inside http://www.beidou.gov.cn/xpnavdata.rar 
1. filename rules
event: Psrname_mmdd_hhmmss.txt (psrname: pulsar name, yyymmmddd_hhmmss: utc 
date of the data)
orbit: orbit_mmdd_hhmmss.txt (utc date of orbit data)


2. orbit file format
time(seconds start from 2008-01-01  00:00:00 UTC)   J2000-x(m) J2000-y(m) 
J2000-z(m)  J2000-vx(m/s) J2000-vy(m/s) J2000-vz(m/s)


3. event file format
TOA (seconds start from 2008-01-01 00:00:00 UTC)  energy(eV)


4. If you are gonna publish the research result please declare the data is from 
www.beidou.gov.cn taken by pulsar observation satellite XPNAV-1.  
5. detector intro: wolter-i focused x-ray detector. energy range: 0.5-10keV. 
view : 2ω=15'.  geometric area: 30cm2@1.5keV. Time resolution:<=1.5us. Energy 
resolution: <=180eV@5.9keV.





-- Original --
From:  "Li Ang";<379...@qq.com>;
Date:  Wed, May 10, 2017 09:45 AM
To:  "time-nuts"; 

Subject:  [time-nuts] First batch data of China pulstar observation satellite



Hi, 
I have just noticed that the data was found at 
http://www.beidou.gov.cn/xpnavdata.rar 
The satellite was built by BD7ILZ's company and launched on 2016.11.10. The 
data is recieved from the Crab nebula.
If you are interested on the data I am happy y to translate the readme.txt 
and related information.


Regards


Li Ang / BI7LNQ
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Re: [time-nuts] Anthorn eLoran

[Iain Young]

On 09/05/17 20:28, moGandalfG8--- via time-nuts wrote:

Iain Young wrote:
I now have all four with green tracking lights, so  looks good to go

Thanks Iain,

Also looking good here now so seems like I cried wolf after all,  although
very happy it wasn't anything more permanent:-)



I noted this morning, mine were all "Red" again. This very much suggests
antenna maintenance (Off while they work on it during the day, and on
once they've finished the day's work before starting work on it again 
the next morning, rather like they do with MSF next door)



Iain

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Re: [time-nuts] Looking for a HP-58503 display

[Tom Knox]

I am 99% sure you are correct, it is the same display as the 53131/2A counter. 
Sadly although in the past I have found and been able to order raw similar 
displays for product such as the 3458A, after a prolonged search I was never 
able to find a part number or order the 58503/53132 displays. Often Agilent 
Keysight kweeps these part numbers in house and does not provide any help with 
part numbers, but if you know the number you can order it. Anyone have any 
insight to the part number?

Cheers;

Thomas Knox




From: time-nuts  on behalf of Mark Sims 

Sent: Tuesday, May 9, 2017 5:25 PM
To: time-nuts@febo.com
Subject: [time-nuts] Looking for a HP-58503 display

I looked closely at the display and can see unused annunciators for frequency, 
us, period, etc.  So the display is the same as used in at least one of their 
frequency counters.  It has 12 alphanumeric digits.
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time-nuts Info Page - American Febo 
Enterprises
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time-nuts is a low volume, high SNR list for the discussion of precise time and 
frequency measurement and related topics. To see the collection of prior 
postings to ...


and follow the instructions there.
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Re: [time-nuts] A good GPS-Receiver with 1PPS output...

[Bob kb8tq]

Hi

For the same money, you could get one of these:

http://www.ebay.com/itm/152340314423?_trksid=p2057872.m2749.l2649=STRK%3AMEBIDX%3AIT
 


Then locking up another oscillator is just a simple phase locked loop. 

The gotcha is that none of the modules on the market actually have a “stable” 1 
PPS. To get that you do a GPSDO. 
The GPS constellation it’s self is what creates the (short term) instability. 
If your OCXO closely follows the GPS signal,
it will be all over the place. There is lots of information about this in the 
archives. 

Bob

> On May 10, 2017, at 3:29 AM, Stephen Tompsett  wrote:
> 
> How about ebay item 251785217093 ?
> 
> 
> 
> On 09/05/2017 20:52, Ulf Kylenfall via time-nuts wrote:
>> 
>> Gentlemen.
>> I am sure this has been asked before...
>> I am looking to purchase a GPS receiver modulethat supplies a good/stable 
>> 1PPS outputwith as little (internally) generated jitter as possible.
>> PCB-style is OK. It is to be usedfor GPS-locking a HP 105B in aseparate box.
>> Miniaturization not necessary at all.
>> Can someone suggest a suitable product(eBay ?)
>> BR
>> Ulf KylenfallSM6GXV
>> 
>> 
>> 
>> 
>> 
>> 
>> 
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>> 
> 
> -- 
> Stephen Tompsett
> 
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Re: [time-nuts] A good GPS-Receiver with 1PPS output...

[Pete Stephenson]

On Tue, May 9, 2017, at 09:52 PM, Ulf Kylenfall via time-nuts wrote:
>  
> Gentlemen.
> I am sure this has been asked before...
> I am looking to purchase a GPS receiver modulethat supplies a good/stable
> 1PPS outputwith as little (internally) generated jitter as possible.

How much jitter is tolerable? What's your budget?

The u-blox NEO-M8T is cheap (a PCB-mounted version is available for USD
$75, see [1]) and according to its brochure[2] it has +/-11ns jitter
with an absolute accuracy of 21ns. That's pretty good.

On that particular board, the PPS line is wired to an LED indicator
light so some light soldering would be needed to run a wire off of that
line to your HP 105B. Alternatively, the shop owner is happy to redesign
the board in whatever wiring configuration you need if you're willing to
buy 10 of the modified board. Keep in mind the connectors on the board
are 1.25mm, so you'd need to be sure you have appropriate connectors,
but those are cheap and readily available on eBay and the like.

Cheers!
-Pete

[1] 
[2]

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[time-nuts] Administrivia: febo.com SSL certificate

[John Ackermann N8UR]

If your browser has been throwing security warnings or errors when you 
try to access the web server at febo.com (for example, the list 
archives), that problem should now be fixed.


I was using an SSL certificate issued by StartSSL, a company that has 
sort of shot themselves in the foot due to their ownership structure and 
lack of transparency.  A few months ago the major browser vendors have 
stopped recognizing certs issued by StartSSL, and their browsers now 
give warnings when they encounter a StartSSL cert.


There's no evidence that my certificate was vulnerable or was ever 
compromised, but I've now changed over to certificates from a 
widely-supported group called LetsEncrypt, and you shouldn't see any 
further security warnings.


Thanks,
John
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Re: [time-nuts] Looking for a HP-58503 display

[Mark Sims]

I was looking at the 34401A service manual.  It shows the VFD pinouts.  Looks 
like 18 pins topside and 16 pins bottom side and is a 14 seg display.   I also 
looked at the 53132A manual.  The 53131/53132/53181 counters use a 14 seg 
display with 18 pins top and bottom.

The 58503B is 14 seg with 18 pins top and bottom.  It appears to be the same 
display as used in the 53131/53132/53181.  Shining a light into the display 
window shows all the enunciators that the 53132 has.

It looks like the 34401A display could be made to work, but would probably 
require some pin origami.
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Re: [time-nuts] A good GPS-Receiver with 1PPS output...

[Stephen Tompsett]

How about ebay item 251785217093 ?



On 09/05/2017 20:52, Ulf Kylenfall via time-nuts wrote:
>  
> Gentlemen.
> I am sure this has been asked before...
> I am looking to purchase a GPS receiver modulethat supplies a good/stable 
> 1PPS outputwith as little (internally) generated jitter as possible.
> PCB-style is OK. It is to be usedfor GPS-locking a HP 105B in aseparate box.
> Miniaturization not necessary at all.
> Can someone suggest a suitable product(eBay ?)
> BR
> Ulf KylenfallSM6GXV
>
>
>
>
>
>
>
> ___
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> and follow the instructions there.
>

-- 
Stephen Tompsett

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[time-nuts] A good GPS-Receiver with 1PPS output...

[Ulf Kylenfall via time-nuts]

 
Gentlemen.
I am sure this has been asked before...
I am looking to purchase a GPS receiver modulethat supplies a good/stable 1PPS 
outputwith as little (internally) generated jitter as possible.
PCB-style is OK. It is to be usedfor GPS-locking a HP 105B in aseparate box.
Miniaturization not necessary at all.
Can someone suggest a suitable product(eBay ?)
BR
Ulf KylenfallSM6GXV







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[time-nuts] Looking for a HP-58503 display

[swperk]

It's the exact same display module as in the 53131A/53132A. It's a Samsung 
INB-12MM53T, Keysight part number 5040-0023. The VFD part itself is an Itron 
CC1187G. 

I've also found a possible part number for the VFD as an Itron CP3033A 
(although that might be the VFD for the 34401A, which would not be compatible 
with the 58503A).

A brief search doesn't turn up any sources for the VFD, much less the entire 
module. 

Alternatively, if you found a 53131A or 53132A with a bright display at a 
reasonable price, it could be used as a parts donor. 

Stan
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