John, Besides the M12 receiver you will need an interface board to provide a 3.3 volt regulator for the M12, a 5 volt regulator and some 74c04's or some such to provide the 1pps interface and drive levels to a MAX232 chip for a RS232 interface. Then you will need to build up the Brooke Shera comparator and control board to interface a high quality oscillator in order to duplicate what is already provided in the Trimble Thunderbolt GPSDO.
The Brooke Shera system gives you a part by part insight on what goes on in the Thunderbolt. However, there is a bit of work to get the Shera system up and running. The advantage of the Thunderbolt is that it is pretty much a plug-n-play unit. 73....Bill....WB6BNQ John Beale wrote: > Hi Murray, > > Thanks to you and the others for your replies. After some more HF reception > problems here, I have come to the same conclusion as you. I found an Oncore > M12+ timing GPS is available pretty cheap from Hong Kong, so that's my plan. > > best regards, > John Beale > > > 1. My best advice is to get hold of a cheap GPS module with a 1pps > (seconds pulse) output. Connect it up, and when you have a fix, use the > 1pps to trigger your digital oscilloscope. Set the timebase to 1us/div to > start with, and ultimately 100ns, and observe the 10MHz output of your > TCXO. You will see the waveform drifting slowly. Counting how long it takes > to slip one cycle will tell you how far off the TCXO is. If you have a > counter with Time Interval mode capability, you could use that, using the > GPS to start and 10MHz to stop, again observing the drift. > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.