Hi all, I started to write the second part of this tutorial but when finished i was not happy with the result. The first thing one can say is that you will need a very frequency stable receiver. Ther
Hi all, I started to write the second part of this tutorial but when finished i was not happy with the result. The first thing one can say is that you will need a very frequency stable receiver. The
Hi Stefan My receiver is an Elad FDM-DUO SDR with a 10 MHz GPS input. Unfortunately SpecLab doesn't have that radio for an SDR input, so I have to use the sound input via USB. I could send the 1 PP
Has anyone tried locking an external USB soundcard to GPS? Chips such as the PCM290x family use their own 12MHz crystal, and it's relatively straightforward to provide 12MHz locked to some master re
Andy, Has anyone tried locking an external USB soundcard to GPS? Chips such as the PCM290x family use their own 12MHz crystal, and it's relatively straightforward to provide 12MHz locked to some mast
Hi Tony, OK so if your RX and PC time is stable, we can give it a try. -You need a stereo input soundcard and feed the PPS signal to the right channel. Just run it at 48 kS/s. The PPS signal must be
Hello Jim, I still wonder why the sync pulses from the Thunderbolt E are so short - you mentioned 10 us in your email, but what is the exact pulse length ? With a slightly modified software (SL) it m
Won't the sound card's input filter, the anti-alias filter, extend this pulse, however short it is, into something the sampling rate will always see? So there is no need to deliberately lenghen it.
Hello Wolfgang, Monday, October 24, 2016 Probably a naive question, but I have a divider board connected to my Trimble Thunderbolt 10MHz output, details in this link to a PDF: http://www.perdrix.co.u
Hi Chris, Whow, that's a nice "mass grave" of logic ICs ! - yes of course, you can use the 1 Hz output. If it has a 50 % duty cycle, it will look just like a 500 ms long sync pulse to the software. I
Hello Jim, Ok thanks for the details. The reason why the Trimble's "Dirac-like" sync pulse didn't work with SL is because SL expects a 'nice' rectangular pulse. It needs that to find out if the sound
It will possibly work if the software (SL) would not expect a 'normal' rectangular pulse, look for the "valid" low->high transition (because some cards have the bad habit of inverting the polarity),
Watch out for another possible ambiguity: how are you going to ensure the rising edge of the divider's 1-Hz output pulse is synchronized with the start of a UTC second? Bill VE2IQ Monday, October 24,
Hello Bill, Nice to hear from you again. Indeed it's a good point, if the GPS isn't only used for frequency calibration but also for absolute timing. I looked at Paul Nicholson's principle of centroi
Hi Jim, I addition to the discussion here some more words. A D flip-flop, used as a frequency divider? Maybe. Or a simple mono-flop. But i can imagine that this can cause a higher jitter to the synci
Hi Stefan Thanks for the next set of instructions. I will get that sorted at the weekend and try it out. I know it might sound unusual but I'm looking forward to nasty winter weather, that is the onl
Hi Jim, Am 25.10.2016 20:12, schrieb [email protected]: Would the GPS units that you mentioned below suffice for the 50uHz bandwidths that could be useful for TA attempts? Yes they will. For examp
