Hi Mark - The Z3801A used the Motorola 6 channel VP Oncore receiver. It employed a pendulum oscillator whose drift characteristics were written to NV RAM at power-down. Constant operation of some VP products caused loss of satellite signal strength and eventually, loss of lock due to crystal drift. Motorola's (not very descriptive) "VP Service Note" is available here: http://synergy-gps.com/support/motorola-legacy-products/ (our web site was hacked and the legacy technical resource material that's "crossed-out" on this page should be available again within the week).
Art Sepin -----Original Message----- From: time-nuts <[email protected]> On Behalf Of Mark Sims Sent: Thursday, June 20, 2019 7:25 PM To: [email protected] Subject: [time-nuts] Z3801A going into Holdover A few months ago, my 3801A started doing this. It was tracking sats well (several years ago I had to replace the receiver because it had lots of problems acquiring and tracking sats). I swapped in a replacement 10811 OCXO and that fixed the problem. Apparently the problem with the receiver not tracking sats is usually due to the oscillator on the receiver drifting out of spec. Some of them have an adjustment screw... _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Flists.febo.com%2Fmailman%2Flistinfo%2Ftime-nuts_lists.febo.com&data=01%7C01%7Cart%40synergy-gps.com%7C73e8a6f8101644c75da308d6f5feca50%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1&sdata=7dbZ6mo0heozHFKy4MkdZEYaGPsYtr1ktxcMi5K1qDs%3D&reserved=0 and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
