On Tue, September 13, 2016 2:24 pm, taylor david wrote: > 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&products_id=234 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

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-taylor@blueyonder.co.uk Twitter: @gm8arv