Hi …. and this fulfills the requirement I mentioned:
“I just want to build one to say I’ve done it” There is *absolutely* nothing at all wrong with that. If this is your goal, you have accomplished it. You likely have learned somethings along the way. If you have a performance goal that is anywhere close to what the $50 to $150 surplus devices will do, this sort of design will not do the job. Figuring out what you want to do *does* matter a lot. Bob > On Apr 4, 2016, at 8:48 PM, dlewis6767 <[email protected]> wrote: > > Lots' of help herein; ...but, also lots' of nay-sayers, too. > > Don't let the nay-sayers scare you. > > A VERY accurate, newbie-based, GPSDO can be built with minimal > investment or cost. > > It's not hard at all. Just Do-It. Mistakes allowed. > > I have built two GPSDO's from scratch. Both worked very well against > each other measured with an HP 5370B; against my rubidium; as well as > my cesium. > > Just look at it at the 'building-block' level. (no real need for an > embedded computer unless you like code more so than dips. :-) > > > 1. Get a good, used, GPS receiver with a 10Khz output. > 2. Get a good, used, 10MHz OCXO with a voltage control. > 3. Design a simple divide-by-thousand divider. > 4. Exclusive-or these two using a 4046 PLL (comparator 1) > 5. Design a voltage tracking / filter to match the OCXO control > requirements. > 6. And, ...ta-dah; > 7. You have a 10MHz, bench frequency standard that will rival all > others; and the best part....you designed and built it! > 8. NOTE: Take the unused, SR flip-flop output of the 4046 PLL and > connect a small, analog, milliampmeter. It will swing back and forth > trackin the XOR function until your GPSDO 'locks'; then become > stationary. > > Basic? Yes! Over-simplified? Probably. > > But it will work and you will feel like you accomplished your goal of > 'doing-it-yourself'. > > -Don > ====================================================== > > > > > >> > > -- > dlewis6767 <[email protected]> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
