> On Oct 5, 2016, at 5:00 PM, Bob Camp <kb...@n1k.org> wrote: > > Hi > > What does the signal you are sampling look like?
The last time I actually looked (it was a while ago), it looked reasonable as closely as I could look, but the ADC resolution is something like 1mV per LSB, and I’m not sure I looked that closely. > > Does it (maybe) have a bit of noise on it? > > If it is the output of a “normal” TDC, then the answer is to sample once. I dunno about a “normal” one… This one is the one I got from Jim Harman. The phase difference between the divided-by-10 output and PPS goes through a diode, JFET and then an RC (with a much higher discharge resistor). As long as you sample at least 1 µs after the PPS (and it takes at least that long to get into the ISR anyway), it *ought* to be stable for dozens of µs. That’s kind of why I’m going down the road of multiple samples - to see if there’s anything to it. _______________________________________________ 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.
