Re: [time-nuts] N1JEZ GPSDO Monitor Software

[Bryan _]

http://infixtechnologies.com/products/GPSMonitor/GPSMonitor.php

-=Bryan=-

> From: w1...@earthlink.net
> To: time-nuts@febo.com
> Date: Wed, 14 Sep 2016 20:51:57 -0700
> Subject: Re: [time-nuts] N1JEZ GPSDO Monitor Software
> 
> GPS Monitor is too vague to do a Google on, can you be a bit more specific ?
> 
> Tnx, Dick, W1KSZ
> 
> -Original Message-
> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bryan _
> Sent: Wednesday, September 14, 2016 6:40 PM
> To: TIme Nuts
> Subject: Re: [time-nuts] N1JEZ GPSDO Monitor Software
> 
> Let me try this again, for some reason my email strips out  on this list 
> Lady Heather, WinOncore12, SirfOnCore, VisualGPSXP, GPS Monitor.
> 
> -=Bryan=-
> 
> > From: bpl...@outlook.com
> > To: time-nuts@febo.com
> > Date: Wed, 14 Sep 2016 18:22:35 -0700
> > Subject: Re: [time-nuts] N1JEZ GPSDO Monitor Software
> > 
> > Few that I have used
> > Lady HeatherWinOnore12SirfOnCoreVisualGPSXP
> > 
> > -=Bryan=-
> > 
> > > From: w1...@earthlink.net
> > > To: time-nuts@febo.com
> > > Date: Wed, 14 Sep 2016 09:00:16 -0700
> > > Subject: [time-nuts] N1JEZ GPSDO Monitor Software
> > > 
> > > I found one that I built many years ago and would like to see if it 
> > > still works.
> > > 
> > > I forget which monitoring software I used, but it most likely is 
> > > woefully out
> > > 
> > > of date today.
> > > 
> > >  
> > > 
> > > Anything else (besides TAC32) that I could use ? 
> > > 
> > >  
> > > 
> > > Tnx, Dick, w1KSZ
> > > 
> > > ___
> > > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > > and follow the instructions there.
> >   
> > ___
> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] N1JEZ GPSDO Monitor Software

[Richard W. Solomon]

GPS Monitor is too vague to do a Google on, can you be a bit more specific ?

Tnx, Dick, W1KSZ

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bryan _
Sent: Wednesday, September 14, 2016 6:40 PM
To: TIme Nuts
Subject: Re: [time-nuts] N1JEZ GPSDO Monitor Software

Let me try this again, for some reason my email strips out  on this list 
Lady Heather, WinOncore12, SirfOnCore, VisualGPSXP, GPS Monitor.

-=Bryan=-

> From: bpl...@outlook.com
> To: time-nuts@febo.com
> Date: Wed, 14 Sep 2016 18:22:35 -0700
> Subject: Re: [time-nuts] N1JEZ GPSDO Monitor Software
> 
> Few that I have used
> Lady HeatherWinOnore12SirfOnCoreVisualGPSXP
> 
> -=Bryan=-
> 
> > From: w1...@earthlink.net
> > To: time-nuts@febo.com
> > Date: Wed, 14 Sep 2016 09:00:16 -0700
> > Subject: [time-nuts] N1JEZ GPSDO Monitor Software
> > 
> > I found one that I built many years ago and would like to see if it 
> > still works.
> > 
> > I forget which monitoring software I used, but it most likely is 
> > woefully out
> > 
> > of date today.
> > 
> >  
> > 
> > Anything else (besides TAC32) that I could use ? 
> > 
> >  
> > 
> > Tnx, Dick, w1KSZ
> > 
> > ___
> > time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
  
___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP-105B Battery Replacement?

[Jeremy Nichols]

Thanks, Brooke, I'll price new Ni-Cads. I wasn't thinking of lead-acid (gel
cells) but rather lithium rechargeable, providing I can find a type that
won't catch fire and will work with the 105B'scircuits.

Jeremy


On Wednesday, September 14, 2016, Brooke Clarke  wrote:

> Hi Alex:
>
> Yes, I'm recommending Ni-Cad but NOT any acid type.
>
> --
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
> http://www.end2partygovernment.com/2012Issues.html
> The lesser of evils is still evil.
>
>  Original Message 
>
>> Hi Brooke,
>>
>> sorry I have to disappoint you; Ni-Cd batteries do not use any acid, they
>> have K-OH  kalium hidrioxid  [potassium hydroxide  for anglophone ] as
>> electrolyte and they are normally very air-tide, and widely used in radios.
>>
>> 73
>>
>> KJ6UHN
>>
>> Alex
>>
>> On 9/14/2016 4:45 PM, Brooke Clarke wrote:
>>
>>> Hi Jeremy:
>>>
>>> It's a very bad idea to put any battery with acid in an enclosure that
>>> has electronics since if it vents the acid will etch the PCBs.
>>> Guess how I learned this.  I got a great price on a Gibbs Frequency
>>> Standard because the oven no longer worked.
>>> http://prc68.com/I/office_equip.html
>>>
>>>
>>> Modern Ni-Cad batteries have much more capacity than older ones and no
>>> longer have a memory effect.  They are also very easy to charge, so why not
>>> just replace the old cells?
>>>
>>>
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/m
>> ailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/m
> ailman/listinfo/time-nuts
> and follow the instructions there.
>


-- 
Sent from Gmail Mobile
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP-105B Battery Replacement?

[Brooke Clarke]

Hi Alex:

Yes, I'm recommending Ni-Cad but NOT any acid type.

--
Have Fun,

Brooke Clarke
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.

 Original Message 

Hi Brooke,

sorry I have to disappoint you; Ni-Cd batteries do not use any acid, they have K-OH  kalium hidrioxid  [potassium 
hydroxide  for anglophone ] as electrolyte and they are normally very air-tide, and widely used in radios.


73

KJ6UHN

Alex

On 9/14/2016 4:45 PM, Brooke Clarke wrote:

Hi Jeremy:

It's a very bad idea to put any battery with acid in an enclosure that has electronics since if it vents the acid 
will etch the PCBs.

Guess how I learned this.  I got a great price on a Gibbs Frequency Standard 
because the oven no longer worked.
http://prc68.com/I/office_equip.html


Modern Ni-Cad batteries have much more capacity than older ones and no longer have a memory effect.  They are also 
very easy to charge, so why not just replace the old cells?




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP-105B Battery Replacement?

[Alexander Pummer]

Hi Brooke,

sorry I have to disappoint you; Ni-Cd batteries do not use any acid, 
they have K-OH  kalium hidrioxid  [potassium hydroxide  for anglophone ] 
as electrolyte and they are normally very air-tide, and widely used in 
radios.


73

KJ6UHN

Alex

On 9/14/2016 4:45 PM, Brooke Clarke wrote:

Hi Jeremy:

It's a very bad idea to put any battery with acid in an enclosure that 
has electronics since if it vents the acid will etch the PCBs.
Guess how I learned this.  I got a great price on a Gibbs Frequency 
Standard because the oven no longer worked.

http://prc68.com/I/office_equip.html


Modern Ni-Cad batteries have much more capacity than older ones and no 
longer have a memory effect.  They are also very easy to charge, so 
why not just replace the old cells?




___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] N1JEZ GPSDO Monitor Software

[Bryan _]

Let me try this again, for some reason my email strips out  on this list
Lady Heather, WinOncore12, SirfOnCore, VisualGPSXP, GPS Monitor.

-=Bryan=-

> From: bpl...@outlook.com
> To: time-nuts@febo.com
> Date: Wed, 14 Sep 2016 18:22:35 -0700
> Subject: Re: [time-nuts] N1JEZ GPSDO Monitor Software
> 
> Few that I have used
> Lady HeatherWinOnore12SirfOnCoreVisualGPSXP
> 
> -=Bryan=-
> 
> > From: w1...@earthlink.net
> > To: time-nuts@febo.com
> > Date: Wed, 14 Sep 2016 09:00:16 -0700
> > Subject: [time-nuts] N1JEZ GPSDO Monitor Software
> > 
> > I found one that I built many years ago and would like to see if it still
> > works.
> > 
> > I forget which monitoring software I used, but it most likely is woefully
> > out 
> > 
> > of date today.
> > 
> >  
> > 
> > Anything else (besides TAC32) that I could use ? 
> > 
> >  
> > 
> > Tnx, Dick, w1KSZ
> > 
> > ___
> > time-nuts mailing list -- time-nuts@febo.com
> > To unsubscribe, go to 
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] N1JEZ GPSDO Monitor Software

[Bryan _]

Few that I have used
Lady HeatherWinOnore12SirfOnCoreVisualGPSXP

-=Bryan=-

> From: w1...@earthlink.net
> To: time-nuts@febo.com
> Date: Wed, 14 Sep 2016 09:00:16 -0700
> Subject: [time-nuts] N1JEZ GPSDO Monitor Software
> 
> I found one that I built many years ago and would like to see if it still
> works.
> 
> I forget which monitoring software I used, but it most likely is woefully
> out 
> 
> of date today.
> 
>  
> 
> Anything else (besides TAC32) that I could use ? 
> 
>  
> 
> Tnx, Dick, w1KSZ
> 
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
  
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] HP-105B Battery Replacement?

[Brooke Clarke]

Hi Jeremy:

It's a very bad idea to put any battery with acid in an enclosure that has electronics since if it vents the acid will 
etch the PCBs.

Guess how I learned this.  I got a great price on a Gibbs Frequency Standard 
because the oven no longer worked.
http://prc68.com/I/office_equip.html


Modern Ni-Cad batteries have much more capacity than older ones and no longer have a memory effect.  They are also very 
easy to charge, so why not just replace the old cells?


--
Have Fun,

Brooke Clarke, N6GCE
http://www.PRC68.com
http://www.end2partygovernment.com/2012Issues.html
The lesser of evils is still evil.

 Original Message 
I recently acquired a nice HP-105B, serial prefix 1240A, and like Perry Sandeen (posted here 10 May 2016) was 
pleasantly surprised to find a 10811-type oscillator inside in place of the old blue oven. Well, the oscillator isn't 
actually labelled "10811" but has a label "Serial No. 3010A62646 / Hewlett Packard / Made in U.S.A. / R11 147K." So, 
this is essentially the same oscillator as Perry found in his 105B.


The oscillator works well although the meter reading for the 5 MHz output is low, about 30 instead of the expected 80 
(per the 105B manual for the 1240A series). The measured output is also low, about 1 Volt where 1.5 Volt is the 
expected minimum. Might this be due to the change from the old 105 crystal oven to the 10811?


What is the received wisdom on replacement of the previously-removed factory Ni-Cad pack? There are many small 12 Volt 
batteries available, two of which would easily fit into the space available and some of which might not even catch 
fire! Other options are an external battery+charger or even a UPS on the AC line. Opinions?


Jeremy / N6WFO


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] HP-105B Battery Replacement?

[Jeremy Nichols]

I recently acquired a nice HP-105B, serial prefix 1240A, and like Perry 
Sandeen (posted here 10 May 2016) was pleasantly surprised to find a 
10811-type oscillator inside in place of the old blue oven. Well, the 
oscillator isn't actually labelled "10811" but has a label "Serial No. 
3010A62646 / Hewlett Packard / Made in U.S.A. / R11 147K." So, this is 
essentially the same oscillator as Perry found in his 105B.


The oscillator works well although the meter reading for the 5 MHz 
output is low, about 30 instead of the expected 80 (per the 105B manual 
for the 1240A series). The measured output is also low, about 1 Volt 
where 1.5 Volt is the expected minimum. Might this be due to the change 
from the old 105 crystal oven to the 10811?


What is the received wisdom on replacement of the previously-removed 
factory Ni-Cad pack? There are many small 12 Volt batteries available, 
two of which would easily fit into the space available and some of which 
might not even catch fire! Other options are an external battery+charger 
or even a UPS on the AC line. Opinions?


Jeremy / N6WFO


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Lady Heather's latest bells and whistles

[Mark Sims]

While on the subject of how GPS receivers do or don't report the day that a 
leapsecond will occur,  I fired up a Nortel/Trimble NTWB receiver to see what 
it said.  It has the standard Trimble packet (0x58:0x05) from which one can 
calculate the day,  but Lady Heather was reporting "Leap Pending!", instead of 
Leap 108 days...  That meant that it has a leap second pending flag, but the 
leap day calculation was over 183 days away.  Hmmm, that shouldn't be.   
Digging deeper, it appears that it is reporting the wn_lsf (GPS week number of 
the leap) as week 2953 (sometime in 2036).  It appears that they are adding the 
week rollover correction to this field twice.

Switching the receiver to SCPI mode (yes they can speak a dialect of SCPI) the 
time of the leap is reported correctly.  The error appears to be in their TSIP 
packet output routine.

For receivers that report a leap second pending flag, but don't report the day 
of the leapsecond,  I just added a feature (that is sure to give TVB apoplectic 
fits).  I ASSume the day of leapsecond as being June 30 or Dec 31 and show the 
number of days until leap based upon that (but include a '?' after the value).  
 Yes, we all know a leapsecond can be added at the end of any month,  but these 
seem to be the days preferred by BIPM lately (March and September being the 
second most likely months).  We'll see how long that ASSumption holds up...


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Ettus OctoClock measurements

[Attila Kinali]

Hoi Anders,


On Mon, 12 Sep 2016 17:54:57 +0300
Anders Wallin  wrote:

> The results are decent but not stellar:
> http://www.anderswallin.net/2016/09/ettus-octoclock-distribution-amplifier/
> 
> In particular the AM noise on the 10MHz looks high. Any thoughts/comments?

I am not surprised. They used a digital clock distribution chip. The chip
is not designed for lowest phase noise, neither is the surrounding electronics.
And selling that whole thing, which is nothing more than the example circuit
in the datasheet, for 1700 is a bit of a rip-off, IMHO.

IIRC your design beats theirs already in performance, doesn't it?

> For 1PPS a 200ps skew between fastest and slowest channel is not the end of
> the world, but I would be interested in the cause. To produce 200ps skew
> both a 4cm trace-length-difference and/or 200 mV of DC-offset (for a 1V/ns
> slewrate signal) seem large?

Not really. They use some unnamed 74x04 instead of a specialized clock
distribution chip (like e.g. LMK00101). They have split the PPS distribution
into two parts, which are symmetric. You can see that clearly from your
measurements. My guess would be that the track lengths on different layers
are not equal for all paths, which introduces quite a bit of skew (thanks
to \epsilon_r changes). That only one port is so much off probably stems from
the need of going around the chip in the hex-inverter package.


Attila Kinali
-- 
Malek's Law:
Any simple idea will be worded in the most complicated way.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Clean 10 MHz ref

[Wes]

On 9/14/2016 2:59 AM, David J Taylor wrote:

It is non-trivial to set other than a few embedded frequencies with the existing
software.  There has been a veiled promise of improved software that remains
unfulfilled.  It is a GPSDO, although the internal oscillator is a TCXO, not an
OCXO.  Mine runs on even a laptop USB port.

Wes
==

Folks,

Mine's running of a standard PC USB port, and the power consumption measures 
between 220 and 240 mA.


With the supplied software (mine dated 2016-May-10, but that may have been the 
install date) setting the frequency is simply typing in the frequency in Hz, 
clicking "Find" and clicking "Update". I've tried a whole variety of random 
frequencies (e.g. 123.456789 MHz) and the device locks within a few seconds.


One limit is that the second output frequency needs to be related to the 
first, as far as I can tell.


Cheers,
David


True for the first frequency.  The second statement may or may not be true, it 
was not clear in the original description of the device.  When I wrote Leo and 
asked about a specific second frequency he did a manual calculation and sent me 
the parameters. From another email reply:


   "Sorry, did not catch your email first time.  Thank you for your custom!

   The numbers are internal settings of PLL chip Si5328 and you can find more
   details here:
   
https://www.silabs.com/Support%20Documents/TechnicalDocs/Si53xxReferenceManual.pdf

   You can set other frequencies just by typing them into Output 1 box and
   clicking "Find"  This will find and program the new frequency.

   If you want two separate frequencies at the same time it gets a bit tricky
   and often need manual setup.  In such case let me know what combination you
   would like and i will try to find the correct settings."

While this is process is helpful, it is hardly convenient and frankly me 
deciphering the doc without a Rosetta Stone isn't going to happen.


Wes, N7WS

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] HP-105B Battery Replacement?

[Jeremy Nichols]

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

[Charles Steinmetz]

Just wanted to add, their US distributor has one with a custom xtal that claims 
even lower phase noise and has provided a plot comparing the two


I see the US distributor says the "custom" unit's phase noise 
"improv[es] on an already impressive figure" of the stock unit.  But in 
reality, even the custom unit doesn't have an "impressive" PN figure -- 
the phase noise is still at least 10dB worse than a real GPSDO.  It 
appears that the outputs are generated by a DDS or similar, so that is 
not surprising.  Good for frequency agility, lousy for frequency 
stability and spurious outputs.


This thing has its place in the world of clocks, but it is *not* a 
precision GPSDO.  It is not even in the league of a number of hobbyist 
and DIY designs.  I wish people would stop recommending it to people 
whose application calls for a real GPSDO (such as multiplying up to the 
GHz region).


Best regards,

Charles


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] N1JEZ GPSDO Monitor Software

[Richard W. Solomon]

I found one that I built many years ago and would like to see if it still
works.

I forget which monitoring software I used, but it most likely is woefully
out 

of date today.

 

Anything else (besides TAC32) that I could use ? 

 

Tnx, Dick, w1KSZ

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Need 10 MHz for DSN space-probe hunting

[Mark Sims]

One thing you can do with a Thunderbolt is to let it settle into to disciplined 
equilibrium to 10.000 MHz, check the DAC voltage serring, and then switch 
off disciplining and manually control the EFC DAC.  This will improve the phase 
noise at the expense of frequency drift which may or may not be an 
issue/compensatable for your application.   

The standard Thunderbolt oscillator has excellent phase noise characteristics 
but is very sensitive to temperature changes.  Lady Heather's PWM'ed fan based 
temperature control can be quite useful for minimizing the effects of 
temperature changes.
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

[time-nuts] Lady Heather's latest bells and whistles

[Mark Sims]

I hope to get the next version out in the next couple of weeks...

Ahhh, the subtile wonders of calculating when a leapsecond happens...   A 
couple of receivers (like 12 channel Motorola receivers) are nice enough to 
directly tell you the date of the leapsecond.  Tthe Z3801A and Z3812A get it 
wrong... they expect it to be within three months of the announcement and were 
saying Sep 30.   When the rollover bug hit mine, in changed to March 31, which 
then gets 1024 weeks added and winds up in the middle of November.

Some other receivers (some Trimble devices, Ublox, NV08C) have a way of 
calculating it from almanac data (but have several complications related to GPS 
week rollovers or day number biases).   If Lady Heather can calculate the date, 
it shows a countdown clock of the number of days (on the day of the leap, it 
shows LEAP PENDING).  If the receiver sends the leapsecond pending flag, but 
not any info about the date, it always shows LEAP PENDING.

-

> I see that with 4.0 I see « LEAP: PENDING! «  whereas on your V4.08 screen 
> shot I see the countdown. Where does LH get this info from?
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Lucent RFTFm-II-XO

[Bill Hawkins]

As to what you would see, find the manual for the Motorola receiver for
details. I don't have the link, but somebody else does.

You get some info about the device and info about each satellite.

You can use a 422 to USB converter or clip on either wire with a digital
scope that decodes simple serial streams, like PicoScope.

Bill Hawkins
 

-Original Message-
From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
Camp
Sent: Wednesday, September 14, 2016 6:13 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Lucent RFTFm-II-XO

Hi

These days, a RS-422 to USB adapter is a sub $20 item, even from a "name
brand" outfit with real drivers. . If you shop a bit, you can get some
dirt cheap USB to 422 adapters at the risk of having issues with the
drivers (now or down the road). 

Bob

> On Sep 13, 2016, at 11:44 PM, Chris Waldrup  wrote:
> 
> Hi,
> 
> Regarding the Lucent box- I wanted to let everyone know that once it
locked to satellites, I have a 10 MHz out. 
> The output was a square wave with some ringing, but I built a three
element low pass filter and now I have a really nice 10 MHz sine wave. 
> Thanks to all!
> 
> Last question I see it has a RS-422 output on one of the
connectors. If I build or buy a 422 to 232 converter can I expect to be
able to view the unit's data output with something like Lady Heather or
Tboltmon? Or at least see an output with Hyperterminal?
> 
> Thank you. 
> 
> Chris
> KD4PBJ
> 
>> On Sep 6, 2016, at 16:42, Bob Camp  wrote:
>> 
>> Hi
>> 
>> One might *think* a redundant system would work fine with the plug
yanked. 
>> In this case .. nope. It needs to have a dummy connector on it to get

>> the device running. I agree that this is an "interesting" way to do 
>> it. Regardless of that, they did the units need the signals from the 
>> other box (or fake signals)  before they will do useful stuff.
>> 
>> Bob
>> 
>> 
>>> On Sep 5, 2016, at 10:22 PM, Bill Hawkins 
wrote:
>>> 
>>> Fake connections? Isn't a redundant system supposed to allow one box

>>> to be disconnected?
>>> 
>>> Bill Hawkins
>>> 
>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob

>>> Camp
>>> Sent: Monday, September 05, 2016 8:20 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Lucent RFTFm-II-XO
>>> 
>>> Hi
>>> 
>>> If you only have one box, you need to be sure the "fake" connections

>>> on the interconnect are correct. If they are not, you will not get 
>>> it to operate correctly.
>>> 
>>> There also is a survey process if you have not had it running in 
>>> your location before. That could take a few hours to a few days 
>>> depending on your antenna.
>>> 
>>> Bob
>>> 
>>> 
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> ___
> time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Jim Miller simple GPSDO

[Tim Shoppa]

There are special "wide-pull-range" VCXO's where a 10MHz unit will indeed
have sensitivity of 600Hz/V or more. e.g.
http://www5.epsondevice.com/en/products/vcxo_standard/vg4231ca.html

I don't know exactly what Epson does inside that particular unit, but a
trick to get wide pull range with discrete circuits is to put two or more
crystals in parallel.

Tim N3QE

On Wed, Sep 14, 2016 at 4:40 AM, Lars Walenius 
wrote:

> The VCXO sensitivity given is strange as it indicates a far to wide span
> so I guessed 30ppm and if it is higher it still needs the damping from
> R2-C2.
> For the OCXO I used the figures given. With 2Hz per volt and 8 Volt span
> you have 16Hz of span. 16Hz divided with 10MHz is 1.6ppm (parts per
> million) can also be said as 1.6us/s.
>
> Lars
>
> >From: Bryan _
> Sent: den 14 september 2016 03:59
>
> >Lars:
> Thank you very much, your explanation was very helpful. I unfortunately
> don't have a background in electronics other than at a hobbyist level, and
> really should just lurk in the back as many of the topics discussed are way
> above me, but I am learning . So forgive this obvious and perhaps dumb
> question but how are you calculating the oscillator spans, you reference
> the VCXO at around 30ppm. I suspect this is because the VCXO has a
> sensitivity of 600-1000hz/v and the OCXO of 1.6ppm has a sensitivity of
> 2hz/v or 3.2/v at 8v. But how are you arriving at the ppm values?
> -=Bryan=-
>
> >> From: lars.walen...@hotmail.com
> > To: time-nuts@febo.com
> > Date: Tue, 13 Sep 2016 20:44:50 +
> > Subject: Re: [time-nuts] Jim Miller simple GPSDO
> >
> > As I have understood it the change of VCXO gain is the reason that R2-C2
> can be omitted. With the VCXO with a large span the damping is needed
> otherwise it will oscillate.
> >
> > The XOR phase detector has a range of 50us with 10kHz in.  The VCXO has
> maybe a span of 30ppm (us/s) and with R1-C1 time constant of about
> 16seconds the phase shift will be close to 180 degrees.
> >
> > With the OCXO with a span of 1.6ppm (us/s) the apparent time constant
> will be about 32 (50/1.6) seconds and the 16 seconds time constant of the
> R1-C1 will act more as a low pass filter at gain cross over with a phase
> shift much below 90 degrees.
> >
> > Sorry for the bad explanation but what I try to say is: If the phase
> detector range  divided with the VCXO span is larger than the R1-C1 time
> constant R2-C2 can be omitted.
> >
> > This thread on EEVblog might be interesting for those that think of
> using the Miller-style GPSDO:
> > http://www.eevblog.com/forum/projects/my-u-blox-lea-6t-
> based-gpsdo-(very-scruffy-initial-breadboard-stage)/msg938013/#msg938013
> >
> > Lars
> >
> > >From: Bryan _
> > >Sent: den 12 september 2016 10:49
> >
> > >Thank you for the reply.
> > Yes, R1/R2/C1/C2 is what I was referencing. I was not sure as the values
> in the schematic are referenced when using the C-MAC (now RAKON) VCXO.
> Further into the material the author switched to a Isotemp 134-10 OCXO and
> used a DC amplifier to compensate for the 0-8v for the EFC, but stated that
> R2 and C2 are not needed when using this OCXO. Not sure why they are
> omitted, is it because of the DC amplifier or because of different specs of
> the OCXO?
> > http://www.jrmiller.demon.co.uk/projects/ministd/dcamp.gif
> >
> > -=Bryan=-
> >
> > >> Date: Mon, 12 Sep 2016 01:25:53 -0700
> > > From: wb6...@cox.net
> > > To: time-nuts@febo.com
> > > Subject: Re: [time-nuts] Jim Miller simple GPSDO
> > >
> > > Hi Bryan,
> > >
> > > No !  Assuming you mean R1/R2/C1/C2 of the Miller schematic, those
> > > values are already set for the comparison frequency (10KHz) of the PLL
> > > phase comparator (U2).
> > >
> > > BillWB6BNQ
> > >
> > >
> > > Bryan _ wrote:
> > >
> > > >Hello:
> > > >I have been following the Jim Miller simple GSDO build project at
> http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm  I have a
> few OCXO's kicking around, but wondering what would the appropriate
> components be for for  R1,R2, C1, C2 to provide the PLL filter. I assume
> the PLL filter needs to be designed to accommodate a specific oscillator
> specifications, or maybe it doesn't really matter and can use the default
> values in the schematic?.
> > > >Was also considering using a picdiv instead of the 2- 74HC390, not
> sure if that would be an advantage or disadvantage in terms of operating
> performance?
> > > >Cheers
>
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/
> mailman/listinfo/time-nuts
> and follow the instructions there.
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

[STR .]

>Briefly, Mike, there's an easy to use unit here, which takes a puck GPS 
>antenna and can run off USB +5V:
> http://www.leobodnar.com/shop/index.php?main_page=product_info_id=234
>
>Perhaps it might meet your needs?
>
>Cheers,
>David

Just wanted to add, their US distributor has one with a custom xtal that claims 
even lower phase noise and has provided a plot comparing the two:
http://www.force12inc.com/products/gps-locked-precision-frequency-reference-low-jitter-gps-clock-450-hz-to-800-mhz-output-custom-low-phase-noise-xtal-version.html

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Lucent RFTFm-II-XO

[Bob Camp]

Hi

These days, a RS-422 to USB adapter is a sub $20 item, even from a “name brand” 
outfit with real
drivers. . If you shop a bit, you can get some dirt cheap USB to 422 adapters 
at the risk of having 
issues with the drivers (now or down the road). 

Bob

> On Sep 13, 2016, at 11:44 PM, Chris Waldrup  wrote:
> 
> Hi,
> 
> Regarding the Lucent box- I wanted to let everyone know that once it locked 
> to satellites, I have a 10 MHz out. 
> The output was a square wave with some ringing, but I built a three element 
> low pass filter and now I have a really nice 10 MHz sine wave. 
> Thanks to all!
> 
> Last question I see it has a RS-422 output on one of the connectors. If I 
> build or buy a 422 to 232 converter can I expect to be able to view the 
> unit's data output with something like Lady Heather or Tboltmon? Or at least 
> see an output with Hyperterminal?
> 
> Thank you. 
> 
> Chris
> KD4PBJ
> 
>> On Sep 6, 2016, at 16:42, Bob Camp  wrote:
>> 
>> Hi
>> 
>> One might *think* a redundant system would work fine with the plug yanked. 
>> In this case …. nope. It needs to have a dummy connector on it to get the 
>> device
>> running. I agree that this is an “interesting” way to do it. Regardless of 
>> that, they
>> did the units need the signals from the other box (or fake signals)  before 
>> they 
>> will do useful stuff.
>> 
>> Bob
>> 
>> 
>>> On Sep 5, 2016, at 10:22 PM, Bill Hawkins  wrote:
>>> 
>>> Fake connections? Isn't a redundant system supposed to allow one box to
>>> be disconnected?
>>> 
>>> Bill Hawkins 
>>> 
>>> -Original Message-
>>> From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob
>>> Camp
>>> Sent: Monday, September 05, 2016 8:20 PM
>>> To: Discussion of precise time and frequency measurement
>>> Subject: Re: [time-nuts] Lucent RFTFm-II-XO
>>> 
>>> Hi
>>> 
>>> If you only have one box, you need to be sure the "fake" connections on
>>> the interconnect are correct. If they are not, you will not get it to
>>> operate correctly. 
>>> 
>>> There also is a survey process if you have not had it running in your
>>> location before. That could take a few hours to a few days depending on
>>> your antenna.
>>> 
>>> Bob
>>> 
>>> 
>>> ___
>>> time-nuts mailing list -- time-nuts@febo.com
>>> To unsubscribe, go to 
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>> 
>> ___
>> time-nuts mailing list -- time-nuts@febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

[Bob Camp]

Hi

> On Sep 13, 2016, at 10:36 PM, Scott Stobbe  wrote:
> 
> Hi bob, thank you for the polite response regarding rise time, indeed I
> would fully agree.
> 
> The rise time I was referring to was the DAC efc value in the plot mark had
> previously attached. He just included a second plot as well. It would
> appear the tbolt is doing something else aggressively before going into
> a PLL, perhaps coarsely phase steering the last +-50 ns, but then runs out
> microseconds in error?

There is some disagreement about the TBolt having multiple lock steps past
the initial jam set of the PPS. What is fairly clear is that it does not step 
gain 
and control settings past the initial “setup” of the PPS.

Bob


> 
> On Tuesday, 13 September 2016, Bob Camp  > wrote:
> 
>> Hi
>> 
>> The rise time of the edge is not a good measure of the accuracy of the
>> timing It
>> simply is a way to look at how fast your gate can ramp a signal.
>> 
>> If you do a long term comparison of the frequency vs time and the time
>> error vs time
>> you will see that a tight (small) damping keeps the time close at the
>> expense of
>> jerking the frequency around a lot. A loose (large) damping does not
>> change the
>> frequency much, but the time wanders quite a bit.
>> 
>> Simply put: There is no free lunch.
>> 
>> Bob
>> 
>>> On Sep 13, 2016, at 9:01 PM, Scott Stobbe 
>> wrote:
>>> 
>>> Bob, that is an excellent proof by contradiction. The reason I asked is
>> on
>>> the plot Mark shared that first rising edge is pretty sharp for a system
>>> with a 500 s time constant.
>>> 
>>> On Tuesday, 13 September 2016, Bob Camp  wrote:
>>> 
 Hi
 
 The pps sync is done by resetting the counter that generates the PPS.
>> At a
 1 ppm frequency
 offset, it could take 500,000 seconds to steer it in with the OCXO. It
 unlikely people would wait
 for over a week for the PPS to line up ….
 
 Bob
 
> On Sep 13, 2016, at 5:58 PM, Scott Stobbe > wrote:
> 
> Interesting discussion about startup. At startup the phase error of the
> synthesized PPS is +- 0.5 s. Is this coarsely set to the nearest ocxo
 cycle
> once gps time is established (would make sense to do it this way), or
>> is
> the half second recovered steering the ocxo?
> 
> On Tuesday, 13 September 2016, Charles Steinmetz <
>> csteinm...@yandex.com
 >
> wrote:
> 
>> Mark wrote:
>> 
>> I just ran a tbolt (which has been off for a couple of months) and
 logged
>>> the state for a couple of hours...  and then remembered something
 about the
>>> initial DAC value setting that I had figured out long ago... it has
 little
>>> to nothing to do with oscillator disciplining.The tbolt drives
>> the
 GPS
>>> from the 10 MHz ocxo.  If the ocxo is too far off freq it can't track
>>> satellites.   The initial dac setting is used to speed up acquisition
 of
>>> satellites and not to speed up the OCXO disciplining loop lock.
>>> 
>> 
>> Well...  by doing the one, it also does the other.
>> 
>> As soon as a satellite is acquired (after a couple of minutes), the
>> DAC
>>> voltage jumps and the disciplining starts.  A few seconds later when
 more
>>> sats are tracked, it gets underway in earnest (and by then the OCXO
>> is
 warm
>>> enought to be within 0.1 Hz).  After 1 hour the box temperature has
>>> stabilized and the freq is within a couple of milli Hz.  After two
 hours
>>> the oscillator has settled down to the point where the DAC curve goes
 into
>>> "wandering around" instead of following  a smooth decay compensating
 for
>>> the oscillator warm-up.  The attached image show the first hour of
>> the
>>> process.
>>> 
>> 
>> If you look carefully at the first 3-4 minutes, you'll see it does
 exactly
>> what I described.  The DAC reference is 0.510v, and the scale is
>> 5000uV/division (=5mV/division).  According to the paramaters, the
 initial
>> DAC voltage (INIT) = 0.499v.  I assume this was previously stored as
>> the
>> DAC value after the Tbolt had fully stabilized, some time in the past.
>> 
>> Sure enough, the DAC voltage starts at just about 0.499v (it looks
>> like
>> 0.494v on the graph), and when the second satellite is acquired it
>> jumps
>> very quickly to 0.529v -- an overshoot of some 55% -- before settling
 back
>> to ~0.518v, at which time it appears to be on frequency within 1e-8 or
 so.
>> From that point disciplining continues as the crystal warms up.
>> 
>> If one accepted my suggestion, the initial DAC voltage would be set to
>> ~0.518v for this oscillator.  In that case, it should be within a few
>> 

[time-nuts] Lady Heather's latest bells and whistles

[Mike Cook]

Hi Mark.

> Le 14 sept. 2016 à 03:51, Mark Sims  a écrit :
> 
> Okee dokeee...  here it is.   Not much difference.   The initial step is 
> smaller,  but it still spikes.  After that things are pretty much the same.   
> After it cool down,  I'm doing another run with the initial voltage set to 
> the peak of the spike.
> 
> One slight difference was with the new initial voltage setting (closer to the 
> current 10. MHz operating point),  it appeared to acquire satellites 
> a few seconds faster (but that could just be luck of the draw).  Setting the 
> initial voltage to something far off of optimum would be interesting... I 
> seem to remember it taking several minutes to acquire.
> 
> (Gratuitous astro feature plug...   Lady Heather can show moon 
> rise/transit/set/age times in addition to the sun times)
> 

I just upgraded from 3.0 beta and was hoping to get these additions from your 
download page, but the V4.00 version doesn’t appear to have them. I see from 
your screen shots that you are up to V4.08. Is this available to the nuts 
public? Another Q. I see that with 4.0 I see « LEAP: PENDING! «  whereas on 
your V4.08 screen shot I see the countdown. Where does LH get this info from?

Thx,
Mike
> --
> 
>> I would be very interested to see the result of another dead cold start 
> of this same Tbolt, with INIT set to 0.518v.  Of course, the time at 
> which the second satellite is acquired (hence, the temperature of the 
> crystal when discipline begins, and thus, the exact DAC voltage required 
> for a stepless transition, will be a bit different from one start to the 
> next, so it won't be perfect.  But it will be a hell of a lot better 
> than starting from 0.499v).
> ___
> time-nuts mailing list -- time-nuts@febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.

"The power of accurate observation is commonly called cynicism by those who 
have not got it. »
George Bernard Shaw

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Need 10 MHz for DSN space-probe hunting

[David J Taylor]

Mike already mentioned he has a Thunderbolt.  That product you referenced
only has phase noise measurements down to 100Hz offset, but comparing to
the Thunderbolt phase noise measurements that Tom posted at the link
below, a Thunderbolt running on a good quality linear power supply has
about 20dB less phase noise at 100Hz:

http://www.leapsecond.com/pages/tbolt/noise.htm

Probably the best solution for Mike is use the Thunderbolt that Mike
already has, get a better power supply, and look at the advice for setting
up the Thunderbolt which has been rehashed on the list over the last few
days (week?  two weeks? I lose track).  For multiplying up you want good
frequency stability, not close tracking of PPS to correct time, so follow
the advice about longer time constant and more damping to get frequency
stability rather than low offset to GPS/NIST time.

Chris Caudle
===

That's why I asked: "Perhaps it might meet your needs?"

I was surprised that the Thunderbolt's suitability was being questioned. 
Wouldn't there be a second PLL loop in the system?


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


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Clean 10 MHz ref

[David J Taylor]

It is non-trivial to set other than a few embedded frequencies with the 
existing

software.  There has been a veiled promise of improved software that remains
unfulfilled.  It is a GPSDO, although the internal oscillator is a TCXO, not 
an

OCXO.  Mine runs on even a laptop USB port.

Wes
==

Folks,

Mine's running of a standard PC USB port, and the power consumption measures 
between 220 and 240 mA.


With the supplied software (mine dated 2016-May-10, but that may have been 
the install date) setting the frequency is simply typing in the frequency in 
Hz, clicking "Find" and clicking "Update".  I've tried a whole variety of 
random frequencies (e.g. 123.456789 MHz) and the device locks within a few 
seconds.


One limit is that the second output frequency needs to be related to the 
first, as far as I can tell.


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


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Jim Miller simple GPSDO

[Lars Walenius]

The VCXO sensitivity given is strange as it indicates a far to wide span so I 
guessed 30ppm and if it is higher it still needs the damping from R2-C2.
For the OCXO I used the figures given. With 2Hz per volt and 8 Volt span you 
have 16Hz of span. 16Hz divided with 10MHz is 1.6ppm (parts per million) can 
also be said as 1.6us/s.

Lars

>From: Bryan _
Sent: den 14 september 2016 03:59

>Lars:
Thank you very much, your explanation was very helpful. I unfortunately don't 
have a background in electronics other than at a hobbyist level, and really 
should just lurk in the back as many of the topics discussed are way above me, 
but I am learning . So forgive this obvious and perhaps dumb question but 
how are you calculating the oscillator spans, you reference the VCXO at around 
30ppm. I suspect this is because the VCXO has a sensitivity of 600-1000hz/v and 
the OCXO of 1.6ppm has a sensitivity of 2hz/v or 3.2/v at 8v. But how are you 
arriving at the ppm values?
-=Bryan=-

>> From: lars.walen...@hotmail.com
> To: time-nuts@febo.com
> Date: Tue, 13 Sep 2016 20:44:50 +
> Subject: Re: [time-nuts] Jim Miller simple GPSDO
>
> As I have understood it the change of VCXO gain is the reason that R2-C2 can 
> be omitted. With the VCXO with a large span the damping is needed otherwise 
> it will oscillate.
>
> The XOR phase detector has a range of 50us with 10kHz in.  The VCXO has maybe 
> a span of 30ppm (us/s) and with R1-C1 time constant of about 16seconds the 
> phase shift will be close to 180 degrees.
>
> With the OCXO with a span of 1.6ppm (us/s) the apparent time constant will be 
> about 32 (50/1.6) seconds and the 16 seconds time constant of the R1-C1 will 
> act more as a low pass filter at gain cross over with a phase shift much 
> below 90 degrees.
>
> Sorry for the bad explanation but what I try to say is: If the phase detector 
> range  divided with the VCXO span is larger than the R1-C1 time constant 
> R2-C2 can be omitted.
>
> This thread on EEVblog might be interesting for those that think of using the 
> Miller-style GPSDO:
> http://www.eevblog.com/forum/projects/my-u-blox-lea-6t-based-gpsdo-(very-scruffy-initial-breadboard-stage)/msg938013/#msg938013
>
> Lars
>
> >From: Bryan _
> >Sent: den 12 september 2016 10:49
>
> >Thank you for the reply.
> Yes, R1/R2/C1/C2 is what I was referencing. I was not sure as the values in 
> the schematic are referenced when using the C-MAC (now RAKON) VCXO. Further 
> into the material the author switched to a Isotemp 134-10 OCXO and used a DC 
> amplifier to compensate for the 0-8v for the EFC, but stated that R2 and C2 
> are not needed when using this OCXO. Not sure why they are omitted, is it 
> because of the DC amplifier or because of different specs of the OCXO?
> http://www.jrmiller.demon.co.uk/projects/ministd/dcamp.gif
>
> -=Bryan=-
>
> >> Date: Mon, 12 Sep 2016 01:25:53 -0700
> > From: wb6...@cox.net
> > To: time-nuts@febo.com
> > Subject: Re: [time-nuts] Jim Miller simple GPSDO
> >
> > Hi Bryan,
> >
> > No !  Assuming you mean R1/R2/C1/C2 of the Miller schematic, those
> > values are already set for the comparison frequency (10KHz) of the PLL
> > phase comparator (U2).
> >
> > BillWB6BNQ
> >
> >
> > Bryan _ wrote:
> >
> > >Hello:
> > >I have been following the Jim Miller simple GSDO build project at 
> > >http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm  I have a  
> > >few OCXO's kicking around, but wondering what would the appropriate 
> > >components be for for  R1,R2, C1, C2 to provide the PLL filter. I assume 
> > >the PLL filter needs to be designed to accommodate a specific oscillator 
> > >specifications, or maybe it doesn't really matter and can use the default 
> > >values in the schematic?.
> > >Was also considering using a picdiv instead of the 2- 74HC390, not sure if 
> > >that would be an advantage or disadvantage in terms of operating 
> > >performance?
> > >Cheers

___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

[Peter Vince]

Hi Scott,

 The x-axis is shown in the dark blue text to the right of the big time
display - 60 minutes total, 5 minutes per division.

 Peter

On 14 September 2016 at 03:52, Scott Stobbe 
wrote:

> Pardon my lack of knowledge regarding Lady Heather, what is the x-axis
> scale? I assumed the text line above the plot is the various y-axis scales.
> This is good data. Thanks
>
___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

Re: [time-nuts] Lady Heather's Tbolt oscillator auto-tune function

[Charles Steinmetz]

Mark wrote:


Okee dokeee...  here it is.   Not much difference.   The initial step is 
smaller,  but it still spikes.  After that things are pretty much the same.   
After it cool down,  I'm doing another run with the initial voltage set to the 
peak of the spike.


Excellent!  Many thanks, Mark.  I'll be interested to see the next run, 
with INIT set to the current peak DAC voltage.  It's looking like some 
glitch may be an inherent feature of the Trimble software.


Back when I was still playing with mine, I noticed that there was often 
an ugly, long spike with an oscillatory tail coming out of holdover. 
Even if the held DAC voltage is very close to the new required DAC 
voltage, jam synch is set very tight, the allowable frequency error in 
recovery is also set very tight, and the PPS phase coming out of 
recovery is small (< 50nS), the control software sends the DAC way off 
into the wilderness for no apparent reason.  That does not seem to be 
driven by the normal discipline loop -- rather, it appears to me to be 
an error in the recovery routine.



One slight difference was with the new initial voltage setting (closer to the 
current 10. MHz operating point),  it appeared to acquire satellites a 
few seconds faster (but that could just be luck of the draw).


Yes, that's an expected outcome -- the closer you start to 10.0, 
the faster it should be able to acquire satellites.  Of course, 
acquisition has lots of other variables, including the position of the 
constellation at start-up time, weather, etc., so we expect it to be a 
statistical trend, not a firm rule.



Setting the initial voltage to something far off of optimum would be 
interesting... I seem to remember it taking several minutes to acquire.


Both of mine had way-off INIT settings when I received them (years ago, 
now), and yes, they took a few minutes longer to acquire the first two 
satellites than after I set INIT to the value that produced the 
smoothest transition.


Thanks again, Mark!

Charles


___
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.