Robert, > Is it dead because of Week-Roll over limits or something else?
It is a Week Roll-Over limit. In a working receiver, the time should be correct with 3-D fix (min) but the date will be wrong. Some VP and UT+ Oncore receivers may have failed but we have found that to be very rare. Art P.S. We use SafeLinks protection for our e-mail so it adds many additional characters while the mail is being tested for virus, etc. in it's sand box. -----Original Message----- From: Robert DiRosario <[email protected]> Sent: Tuesday, June 22, 2021 1:49 PM To: [email protected] Subject: [time-nuts] Re: Z3801A Receiver Replacement Does this effect All Z3801As? I have one of these: https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.realhamradio.com%2FGPS_Frequency_Standard.htm&data=04%7C01%7Cart%40synergy-gps.com%7C9aec8b93f8564034a80a08d935c8ce5c%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1%7C0%7C637599958847941854%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=N%2Fv%2B8URtNzXTNriy92U9kAuYLDhIufaHIq2%2BClC5qC8%3D&reserved=0 I picked up a power supply and antenna for it but haven't done anything with it yet. > I have a HP Z3801A with a dead GPS receiver. Is it dead because of Week-Roll over limits or something else? Robert On 06/21/2021 11:54 PM, Art Sepin wrote: > Hi Fred, > > I apologize if the following smells overtly commercial; it's only intended to > answer your questions and explain where we are in the process of producing > GPS replacement products for legacy timing instruments. > > The 6 and 8 channel Motorola VP and 8 channel UT+ will not work as > replacements. Those products have also reached their 1024 Week-Roll Over > limits. The HP Z3801A and Z3805A products only respond to 6 channel commands > and produce 6 channel reply messages. > > We have developed single-board clones for the Motorola VP and UT+ products, > as drop-in replacements, that are lower in cost than Synergy's 2-board > Adaptor Board products (Shooting for dropping to less than $190 if component > prices don't go even higher!). The SSR-VP can plug into the HP Z3801A and > Z3805A products. > > A different part number SSR-VP designed to drop into HP 58503A and an > SSR-UT+, designed to drop into HP 58503B products, have also been completed > but firmware for those have yet to be tested in actual instruments. With the > proper firmware loads, the SSR Drop-In products should be candidates for > upgrading many other legacy timing instruments. > > We had planned for the single board "Drop-In" products to be available near > the end of 2020 but COVID-19 changed things for us. We are now planning a > small production run to satisfy folks that have already been in touch with us > but we need to complete our boot-loader for firmware updates first. With > current work load, I'd estimate 90 - 120 days for HP Z3801A and Z3805A > replacements. If you are interested we can put you on our list. > > Apologies for the quasi-commercial intrusion! > > Art > > > -----Original Message----- > From: Frederick Bray <[email protected]> > Sent: Monday, June 21, 2021 7:21 PM > To: [email protected] > Subject: [time-nuts] Z3801A Receiver Replacement > > I have a HP Z3801A with a dead GPS receiver. I understand that it is > possible to drop in an Oncore VP 8 channel receiver as a replacement -- not > withstanding the fact that the Z3801A will only see six channels. > > I see that Motorola R5122U1154 8 channel receivers are available. Does > anyone know whether this will function in the Z3801A? I'd like to get it > working again. > > Thanks. > > Fred Bray, KE6CD > > > > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe send an > email to [email protected] To unsubscribe, go to and follow the > instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] -- To unsubscribe > send an email to [email protected] To unsubscribe, go to and > follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] -- To unsubscribe send an email to [email protected] To unsubscribe, go to and follow the instructions there.
