Re: [time-nuts] Beginners GPS locked frequency counter question

On 10/31/15 7:32 PM, Bob Camp wrote: Hi So … how good is the “calibrate and go” (not the tone on second channel) approach likely to be? If it’s a bare crystal or normal XO (not a TCXO) that is supplying the clock, the crystal will follow some fairly well known curves. Which one of the curves

Re: [time-nuts] Beginners GPS locked frequency counter question

> On Oct 31, 2015, at 3:29 PM, Magnus Danielson > wrote: > > Some people is very fond of using the frequency measure of counters, I've > grown more and more sceptic to it for a number of reasons when doing ADEV and > friends, then I use TI that avoids a number of

Re: [time-nuts] Beginners GPS locked frequency counter question

Hi So … how good is the “calibrate and go” (not the tone on second channel) approach likely to be? If it’s a bare crystal or normal XO (not a TCXO) that is supplying the clock, the crystal will follow some fairly well known curves. Which one of the curves it follows will depend entirely on

Re: [time-nuts] Beginners GPS locked frequency counter question

Chris, Can a soundcard be locked to GPS instead of its own internal crystal for precise frequency output? I do not know which soundcard you have in mind - hope to be not totally off-topic. I use a KS-24361 10MHz signal at the Mutec MC-3+ reference input to feed MC-3+ generated word clock with

Re: [time-nuts] Beginners GPS locked frequency counter question

Chris: If by "purely mathematical" you mean with infinite precision and infinite accuracy in the calculations, then the answer is "No." The counter is using integer mathematics, in a world with propagation delays and clock jitter, and uncontrolled phase relationships. So resulting rounding

Re: [time-nuts] Beginners GPS locked frequency counter question

On 10/31/15 3:50 AM, Chris Wilson wrote: 31/10/2015 10:46 I have a Racal counter locked to 1 MHz on its rear panel external input socket from my Trimble Thunderbolt GPS. I derive the 1 Mhz from a David Partridge divider board. If I also feed the counter with the 10 Mhz

Re: [time-nuts] Beginners GPS locked frequency counter question

Hi Chris, On 10/31/2015 11:50 AM, Chris Wilson wrote: 31/10/2015 10:46 I have a Racal counter locked to 1 MHz on its rear panel external input socket from my Trimble Thunderbolt GPS. I derive the 1 Mhz from a David Partridge divider board. If I also feed the counter with

Re: [time-nuts] Beginners GPS locked frequency counter question

Am Sat, 31 Oct 2015 10:50:36 + schrieb Chris Wilson : > > > 31/10/2015 10:46 > >I have a Racal counter locked to 1 MHz on its rear panel external >input socket from my Trimble Thunderbolt GPS. I derive the 1 Mhz >from a David Partridge divider board. If

Re: [time-nuts] Beginners GPS locked frequency counter question

Chris welcome to the group. Several comments. The 1 or 2 Hz most likely is trigger and jitter. Its somewhat odd that you are off by 2 Hz. Typically its 1 Hz. I suspect you are also working 136 KHz. With respect to sound cards the internal clock could be replaced and locked if its at all

Re: [time-nuts] Beginners GPS locked frequency counter question

Hi > On Oct 31, 2015, at 6:50 AM, Chris Wilson wrote: > > > > 31/10/2015 10:46 > > I have a Racal counter locked to 1 MHz on its rear panel external > input socket from my Trimble Thunderbolt GPS. I derive the 1 Mhz > from a David Partridge divider board. If I

Re: [time-nuts] Beginners GPS locked frequency counter question

On Sat, October 31, 2015 10:03 am, Graham / KE9H wrote: > The sound card sampling clock is > usually derived from some master clock in the computer, such that the > sound card is running in the same clock domain as the rest of the computer, so > you more likely need to GPS lock the whole computer.

Re: [time-nuts] Beginners GPS locked frequency counter question

> As an aside, I work low frequency RF transmissions on 136 Mhz, and > very narrow bandwidth. Can a soundcard be locked to GPS instead of > its own internal crystal for precise frequency output? Chris, It might first be interesting to see how far off the frequency is before you worry

Re: [time-nuts] Beginners GPS locked frequency counter question

Hi Chris and Bob, On 10/31/2015 02:13 PM, Bob Camp wrote: Hi On Oct 31, 2015, at 6:50 AM, Chris Wilson wrote: 31/10/2015 10:46 I have a Racal counter locked to 1 MHz on its rear panel external input socket from my Trimble Thunderbolt GPS. I derive the 1

Re: [time-nuts] Beginners GPS locked frequency counter question

Hi > On Oct 31, 2015, at 6:29 PM, Magnus Danielson > wrote: > > Hi Chris and Bob, > > On 10/31/2015 02:13 PM, Bob Camp wrote: >> Hi >> >> >> >>> On Oct 31, 2015, at 6:50 AM, Chris Wilson wrote: >>> >>> >>> >>> 31/10/2015 10:46 >>> >>>

Re: [time-nuts] Beginners GPS locked frequency counter question

.  Someone who has done soundcard FFT programming might have a better idea. Bob From: Tom Van Baak <t...@leapsecond.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Saturday, October 31, 2015 7:58 PM Subject: Re: [time-nuts] Beginner