For the curious, the source for this is here: https://web.tapr.org/~n8ur/PIC_Code/
When I read that it uses a only a PIC, I was skeptical, but then when I read that jitter is in the range of 1 pico second, I was intrigued. It’s a neat solution, the 10 MHz input signal is used as the clock for the PIC, the code relies on a hand crafted carefully timed loop and the PIC’s fixed 400ns instruction cycle to create a very stable output. Crafty. It’s a bit like the Atari 2600 running in lock step with the horizontal blanking period. Ahh, I see Tom Van Baak is responsible for this idea. Nice work! > On Jan 5, 2022, at 5:59 PM, W7SLS <w7sls.sc...@gmail.com> wrote: > > Adam, > > You might already know this, but if not … > > To add on to Bob’s suggestions, if you have more money than time, > TAPR has some ‘divide to 1 pps’ devices: > > https://tapr.org/product/tadd-2-mini-pulse-per-second-divider/ > > And some ‘compare 1 pps devices’: > > https://tapr.org/product/tapr-ticc/ > > I have no financial connection to TAPR, except as a member (hmm, time to > renew, probably). > > Good luck on your adventures! > > Sent from my iPad > >> On Jan 5, 2022, at 5:33 PM, Bob kb8tq <kb...@n1k.org> wrote: >> >> Hi >> >> In general, eBay is your friend for stable crystal oscillators at a >> “friendly” price. Even if you buy 10 to get one, the price is still pretty >> good. What you learn testing them is indeed “Time Nut Stuff”. >> >> Just what’s a good deal varies almost week to week. It is very much a >> shop shop shop sort of thing. >> >> Best / quickest / easiest way to use all these gizmos: Program up a PIC >> to divide them to 1 pps and go from there. >> >> Bob >> >>>> On Jan 5, 2022, at 6:01 PM, Adam Space <time.isan...@gmail.com> wrote: >>> >>> My question is rather open ended. I'm relatively new to timing and whatnot. >>> So far I have mainly dabbled in NTP, and some GPS stuff with a Raspberry Pi >>> with a GPS hat. But both of these are limited to timekeeping on an actual >>> computer system, but I'd like to get into some of the more hardware stuff, >>> and I figured a crystal oscillator would be a good place to start. >>> >>> My knowledge of hardware is pretty weak, so I am unsure of how stuff works >>> in this realm. For example, a quick google search shows very cheap crystal >>> oscillators, like these >>> <https://www.digikey.com/en/products/detail/cts-frequency-controls/MXO45-3C-10M000000/1801887>. >>> But I am confused on how I could exactly use this. One thing I like about >>> NTP is that I can see and compare different clocks, and synchronize them >>> to time-scales like UTC, and track their performance over time. But if I >>> have a crystal oscillator going, how could I compare it or adjust it to >>> other clocks on my network, or to UTC for example? >>> >>> Or to take another example, suppose I have a few crystal oscillators like >>> the one above. Is there a way I could compare them to each other, or log >>> the offsets from each other, and so on? Ultimately, it would be nice to >>> compare the frequency and time offsets to a reference source that is >>> accurate long-term, like my GPS hat Raspberry Pi. >>> >>> Any ideas, suggestions, or clarifications are welcome. Additionally, if >>> anyone knows of any guides (either text, video, or whatever), that would be >>> great too. >>> >>> Adam >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send >>> an email to time-nuts-le...@lists.febo.com >>> To unsubscribe, go to and follow the instructions there. >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an >> email to time-nuts-le...@lists.febo.com >> To unsubscribe, go to and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an > email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.