Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-08 Thread Adrian Godwin
>>>> 23.698519 281736.4 3 >>>> 24.698519 281768.2 3 >>>> 25.698519 281813.6 3 >>>> 26.698519 281847.9 3 >>>> 27.698519 281872.4 3 >>>> 28.698519 281899.0 3 >>>> 29.698519 281919.0 3 >>>> 30.698519 281950.0

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-08 Thread Magnus Danielson
gnus Danielson" <mag...@rubidium.dyndns.org> To: <time-nuts@febo.com> Cc: <mag...@rubidium.se> Sent: Thursday, October 06, 2016 3:40 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? Hi, On 10/06/2016 08:38 PM, Bob Camp wrote: Hi One very simp

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-07 Thread Adrian Godwin
t;> 43.698517 282126.1 3 >> 44.698517 282143.3 3 >> 45.698517 282150.0 3 >> 46.698517 282162.9 3 >> 47.698517 282188.4 3 >> 48.698517 282213.4 3 >> 49.698517 282244.7 3 >> 50.698517 282255.4 3 >> 51.698517 282260.3 3 >> 52.698517 282280.5 3 >>

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-07 Thread Bob Stewart
net> To: Discussion of Precise Time and Frequency Measurement <time-nuts@febo.com> Sent: Wednesday, October 5, 2016 12:37 PM Subject: [time-nuts] Measure GPSDO stability with minimum resources? For my GPSDO, I need to calculate the OCXO aging for holdover projection purposes as well

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-07 Thread Magnus Danielson
3 a= 2.793488e+05 b= -2.535462e+00 c= 7.822419e+02 p4th D > /tvb - Original Message - From: "Magnus Danielson" <mag...@rubidium.dyndns.org> To: <time-nuts@febo.com> Cc: <mag...@rubidium.se> Sent: Thursday, October 06, 2016 3:40 PM Subject: Re: [time-nuts] Me

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-07 Thread Tom Van Baak
;mag...@rubidium.se> Sent: Thursday, October 06, 2016 3:40 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? Hi, On 10/06/2016 08:38 PM, Bob Camp wrote: > Hi > > One very simple experiment: > > Take a HP that has been off power for a year or so. Fire

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Magnus Danielson
;time-nuts@febo.com> Sent: Thursday, October 6, 2016 12:24 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? Hi As normally used, the term “aging” means the long term drift in the frequency of an OCXO. It is independent of the temperature effects and things like retrace, wa

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread jimlux
On 10/6/16 10:11 AM, Chris Albertson wrote: Wouldn't "aging" be the change in the temperature v. frequncy graph over time? It is hard to hold temperture constant so maybe record the function at several different times. This is one big advantage of using a microprocessor inside the GPSDO,

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Tom Van Baak
and frequency measurement" <time-nuts@febo.com> Cc: <hmur...@megapathdsl.net> Sent: Wednesday, October 05, 2016 10:14 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? > > j99har...@gmail.com said: >> Unless the oscillator is still warming up, 5 m

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Bob Camp
and frequency measurement <time-nuts@febo.com> > Sent: Thursday, October 6, 2016 12:24 PM > Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? > > Hi > > As normally used, the term “aging” means the long term drift in the frequency > of an O

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Bob Stewart
hursday, October 6, 2016 12:37 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? The HP Smartclock app note will help you a lot: http://leapsecond.com/hpan/an1279.pdf There are lots of Z3801A EFC curves on the web for you to see what typical range of unit-to-unit varia

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Bob Stewart
ts@febo.com> Sent: Thursday, October 6, 2016 12:24 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? Hi As normally used, the term “aging” means the long term drift in the frequency of an OCXO. It is independent of the temperature effects and things like retrace

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Tim Shoppa
The HP Smartclock app note will help you a lot: http://leapsecond.com/hpan/an1279.pdf There are lots of Z3801A EFC curves on the web for you to see what typical range of unit-to-unit variation is. Of course to actually test holdover, you do that by opening the PLL loop (unhook GPS antenna) and

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Bob Camp
Hi As normally used, the term “aging” means the long term drift in the frequency of an OCXO. It is independent of the temperature effects and things like retrace, warmup, and voltage stability. It is rare that there is any impact on the aging of a properly designed OCXO from drift of the

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-06 Thread Chris Albertson
Wouldn't "aging" be the change in the temperature v. frequncy graph over time? It is hard to hold temperture constant so maybe record the function at several different times. This is one big advantage of using a microprocessor inside the GPSDO, It can log internal data to either a SD card or

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-05 Thread Hal Murray
j99har...@gmail.com said: > Unless the oscillator is still warming up, 5 minutes or even 60 is way too > short a time to look at aging. For aging, you will want to look at the > change in DAC values over several days at least. I think it's worse than that. You have to hold the temperature

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-05 Thread Bob Stewart
.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Jim Harman <j99har...@gmail.com> To: Bob Stewart <b...@evoria.net>; Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Wednesday, October 5, 2016 9:14 PM Subject: R

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-05 Thread Jim Harman
On Wed, Oct 5, 2016 at 6:46 PM, Bob Stewart wrote: > What I'm really looking for is a way to do everything in the PIC. I've > been experimenting with saving the DAC value in a circular queue every 20 > seconds for 60 minutes, and plotting the difference value between the head >

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-05 Thread Bob Stewart
nd frequency measurement <time-nuts@febo.com> Sent: Wednesday, October 5, 2016 4:37 PM Subject: Re: [time-nuts] Measure GPSDO stability with minimum resources? On Wed, Oct 5, 2016 at 1:37 PM, Bob Stewart <b...@evoria.net> wrote: For my GPSDO, I need to calculate the OCXO aging for holdo

Re: [time-nuts] Measure GPSDO stability with minimum resources?

2016-10-05 Thread Jim Harman
On Wed, Oct 5, 2016 at 1:37 PM, Bob Stewart wrote: > For my GPSDO, I need to calculate the OCXO aging for holdover projection > purposes as well as get some figure of merit for the recent past of the > OCXO stability. Do you have a serial port or some way of generating a

[time-nuts] Measure GPSDO stability with minimum resources?

2016-10-05 Thread Bob Stewart
For my GPSDO, I need to calculate the OCXO aging for holdover projection purposes as well as get some figure of merit for the recent past of the OCXO stability.  The latter is so that I can determine that the PLL has (or soon will have) a good lock.  I'm developing on a dfPIC33FJ128MC802, and