Hi
> On Oct 31, 2015, at 6:50 AM, Chris Wilson <[email protected]> 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 direct output from the same GPS it reads one or two > Hz out. As I assume the counter is working purely mathematically > why would that be please? Is it always out in the same direction ( = broken counter) or does it bounce back and forth to each side of “correct” ( = noise) ? > > > 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? Yes and there are threads on the list about doing this. The quick wrap up is: 1) Find the clock source (oscillator or crystal) on the sound card. 2) Pull it off the card and attach a cable. 3) Synthesize the correct frequency off of your GPSDO’s output (generally with some sort of PLL / VCO arrangement) 4) Feed the signal into the cable to the sound card Bob > > Thanks. > > -- > Best Regards, > Chris Wilson. > mailto: [email protected] > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
