[time-nuts] Re: Z3801A GPS Rx board substitute?
Hi, Yes, we're still very much in business but COVID and commercial business commitments have affected my pet VP/UT+ replacement project (for the rest of us). The single board SSR-VP B-1, 6 channel board works in HP Z3801A/Z3805A products and we're now testing in 8 channel VP and UT+ Datum/Symmetricom products. The updated SSR-VP/UT+ datasheet will be available on our web site in the next few days. We're starting a protection run now but component availability remains extremely long. Some components are out to 36 weeks ARO and we need a couple of weeks more for manufacture, test and burn-in. We can be contacted off-list (a...@synergy-gps.com) to be added to the list and receive periodic updates - Thanks! Apologize in advance for any overtly commercial references! Art -Original Message- From: Andrew Kalman Sent: Friday, April 8, 2022 6:21 PM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Re: Z3801A GPS Rx board substitute? I pinged Art at oemi...@synergy-gps.com some time ago as they appear to have announced a drop-in replacement for the Oncore modules, but I never got a response. Dunno if they are still in business, etc. I would like some for my HP Z3805As ... He had previously posted to time-nuts: " "*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."* " --Andrew Andrew E. Kalman, Ph.D. On Fri, Apr 8, 2022 at 3:01 PM Dan Rae via time-nuts < time-nuts@lists.febo.com> wrote: > My faithful 3801, some 207 thousand hours old, has developed an > occasional fault that I think must be down to the Motorola Oncore 6 > channel board and I wonder if there is an available unit that could > replace this, or what the recommended substitute is? eBay searches > don't show any of the original ones. I'd like to keep it going, it was > the first GPSDO I got, and despite getting and building many others > since, I'm stupidly fond of it. > > Thanks, > > Dan > > ___ > 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] Re: Z3801A Receiver Replacement
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 Sent: Tuesday, June 22, 2021 1:49 PM To: time-nuts@lists.febo.com 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 > Sent: Monday, June 21, 2021 7:21 PM > To: time-nuts@lists.febo.com > 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 -- 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.
[time-nuts] Re: Z3801A Receiver Replacement
Thanks, Jan. You are now on the list. Art -Original Message- From: Jan Boutsen Sent: Monday, June 21, 2021 9:27 PM To: 'Discussion of precise time and frequency measurement' Cc: 'Jan Boutsen' ; Art Sepin Subject: RE: [time-nuts] Re: Z3801A Receiver Replacement Art, Thanks for the info. Please do put me on the list for updates. Jan ON4MMW -Original Message- From: Art Sepin Sent: Tuesday, June 22, 2021 5:54 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Re: Z3801A Receiver Replacement 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 Sent: Monday, June 21, 2021 7:21 PM To: time-nuts@lists.febo.com 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 -- 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] Re: Z3801A Receiver Replacement
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 Sent: Monday, June 21, 2021 7:21 PM To: time-nuts@lists.febo.com 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 -- 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.
Re: [time-nuts] EOL Motorola Oncore Remote Antenna
> To me it looks more like water ingress through micro-cracks in the > plastic-dome, and the O-ring did its job and kept that water in. Interesting. That's the first we've heard about micro-cracks in the Radome but that's certainly a likely possibility with such a long exposure to U/V. The more common failure mode reported was moisture ingress due to "breathing;" the uptake of moisture laden air past the O-Ring, due to a small pressure differential. But, once the moisture was inside, it was also trapped internally by the O-Ring. This condition was reported more often in geographic areas that experienced a wide variation in barometric pressures. Art -Original Message- From: Poul-Henning Kamp Sent: Sunday, November 29, 2020 11:19 PM To: Discussion of precise time and frequency measurement ; Art Sepin Subject: Re: [time-nuts] EOL Motorola Oncore Remote Antenna > It's obvious from the photo that the O-Ring seal failed its purpose > over its many years of service. Has the unit totally failed or does the > electronic portion still function? No, the electronics is stone dead. To me it looks more like water ingress through micro-cracks in the plastic-dome, and the O-ring did its job and kept that water in. The microcracks are uniform and seem to follow the molding flow, and that is probably to be expected in our climate: We have a lot of humid freeze-thaw cycles. I wonder if buffing the radomes with car-wax would help ? > I said lucky because I found some GSynQ parts here in an engineering > storage cabinet that we can send to you at no charge to revive your unit. Thanks for the offer, but dont bother: I had a spare on hand, and I may still have third one lying around somewhere. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] EOL Motorola Oncore Remote Antenna
Hello Poul, You are the lucky owner of a Synergy GSynQ smart antenna product manufactured from the late nineties to the early two-thousands when it was replaced with a Synergy Super-Rugged Antenna (SRA). The GSynQ product was produced by lifting the hood of the Motorola Timing2000 GPS antenna, and inserting an interface board with a Motorola M12+ (and later iLotus M12M) plugged into it. https://synergy-gps.com/wp-content/uploads/2018/11/gsynq-mki-a_ug_422_10001500d.pdf https://synergy-gps.com/wp-content/uploads/2018/11/g-synq-rs-422-eval-kit.pdf >From your photo, I can't tell if it is an RS-232 or RS-422 version - please >advise. It's obvious from the photo that the O-Ring seal failed its purpose over its many years of service. Has the unit totally failed or does the electronic portion still function? I said lucky because I found some GSynQ parts here in an engineering storage cabinet that we can send to you at no charge to revive your unit. Please let us know what Motorola binary commands you are using off list. If they match what the Synergy SSR-6Tf produces (M12+/M12M compatible) we'll include one of those in the refurbish kit also at no charge if you will pay the freight/customs charges from San Diego, CA. Art -Original Message- From: time-nuts On Behalf Of Poul-Henning Kamp Sent: Saturday, November 28, 2020 11:48 AM To: time-nuts@lists.febo.com Subject: [time-nuts] EOL Motorola Oncore Remote Antenna The first Motorola Oncore Remote antenna I bought has failed after some 20 years of continuous service in Danish climate: https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fphk.freebsd.dk%2Fhacks%2F20201128_EOL_Motorola_Oncore_Remote&data=04%7C01%7Cart%40synergy-gps.com%7C54752584d47a43ddd93808d893dd1b25%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1%7C0%7C637421925159068239%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=3jn6Rt%2BSEMC4DvapC4v%2F2Iux%2BSgRmzGZlnAPmg95EsU%3D&reserved=0 -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ time-nuts mailing list -- time-nuts@lists.febo.com 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=04%7C01%7Cart%40synergy-gps.com%7C54752584d47a43ddd93808d893dd1b25%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1%7C0%7C637421925159068239%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=qlkSa1pVLrL6kRg2riduKSEv%2BuPHanvvyLUM2J19H2M%3D&reserved=0 and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Z3801A Replacement GPS Receiver
Hello, The 1024 Week Roll-Over date for the last of the 6 channel VP Oncore receivers was in December 2013. They would continue to operate but with an incorrect date. We want to avoid blatant commercialism here but folks should know that Synergy developed a 6 channel VP Oncore replacement that plugs into HP Z3801A and Z3805A slots. It's described here: https://synergy-gps.com/synergy-products/ssr-series-adaptor-boards-for-vp-oncore/. We're working on replacement boards 6 and 8 channel VP and UT+ Oncore receivers in other legacy instrumentation products, including those from HP, Efertom, Datum, Timing Solutions, Symmetricom, Austron and others. A lower cost, single board version (no Adaptor Board) will be available soon. The datasheet and pricing should be available in a week or so with shipments probably starting in the January/February time frame (delayed by COVID-19 and the holiday season). If there is any interest in this type of replacement product, please contact us off-list at oemi...@synergy-gps.com. Art -Original Message- From: time-nuts On Behalf Of Frederick Bray Sent: Saturday, November 14, 2020 5:22 PM To: time-nuts@lists.febo.com Subject: [time-nuts] Z3801A Replacement GPS Receiver It looks like the GPS receiver in my Z3801 may have died. I'm looking for a replacement module and noticed that in the past these have been salvaged from old handheld GPS units. If I can't find the appropriate Oncore module, I might try looking for the handheld unit that contained them. Does anyone recall which units these were? Thanks. KE6CD ___ time-nuts mailing list -- time-nuts@lists.febo.com 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=04%7C01%7Cart%40synergy-gps.com%7C611e398cc1c34e9ad96908d889214c97%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1%7C0%7C637410123408386866%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=wx1%2B5GEUJ0SEso3TfNuSmU1VQszntZafOnqvJYI%2BeAo%3D&reserved=0 and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] HP 58503A GPS receiver not locking to GPS
This Motorola Service Bulletin astonished users in the timing community who kept their VP Oncore timing products operating 24/7/365 - Most everyone! https://synergy-gps.com/wp-content/uploads/2019/06/VP_SERVICE_NOTE.pdf All of the PVT6, 6 and 8 channel Basic Oncore and 6 and 8 channel VP Oncore OEM GPS receiver boards incorporated a Pendulum Oscillator that was recalibrated every time the boards were power cycled. If the receivers were powered-on for long periods, no calibration occurred so it was possible for the oscillator to drift beyond a point where a board could easily acquire satellites; even if powered off for a short period. Randy Warner (RIP) authored an App-Note "Startup Times for VP Oncore Receivers" that discusses the details (our web site was hacked and we're still in the process of replenishing content that was deleted. The text of Randy's App-Note is below). A condition not mentioned in either one of these App-Notes was brought to our attention by our friend, Doug Baker (then at Datum Corp.) sometime in the late nineties. Long term, always on, operation in CDMA cell sites would also suffer from this oscillator drift problem. Anyone with 6 and 8 channel VP Oncore based timing instruments may have noticed this phenomenon too: The longer these VP receivers remained in a powered-on state, the more the oscillator drifted due to no recalibration occurring. The oscillator drift caused the receiver to take longer to acquire satellites as they rose up from the horizon. An attendant effect of not re-calibrating the oscillator was that the longer the receivers were powered on, they appeared to become less sensitive. For example, a receiver installed at a new site that was continuously locking on to 5 to 8 satellites would only be able to see something like 2 to 5 satellites if powered on continuously for more than a year, or so. That's why Motorola generated the VP Oncore Service Note recommending periodic power cycling. BTW - The 1024 Week Roll-Over for a VP Oncore with v8.8 firmware was 3/22/2016; With v10.0 firmware was 8/13/2017 and with v10.1 firmware was 7/11/2018. These receivers will continue to operate but with incorrect dates. We know of no resource for information about VP Oncore behavior with future Week Roll-Overs, Leap Second, etc. Apologies for the long-winded explanation! Art Sepin START UP TIMES FOR VP RECEIVERS At first glance, it probably seems a little strange for me to be writing an application note for the Motorola VP OncoreTM series of GPS receivers fully six months after they were phased out due to parts procurement problems, but I am getting enough calls, emails, and receivers returned due to extended Time To First Fix (TTFF) to warrant a quick note. HISTORY - One result of the impending phase out is that Synergy Systems purchased quantities of VP receivers from other Motorola distributors world-wide in order to support our customers for as long as possible. These receivers included 6 channel B1's and 6/8 channel B3's and B8's. Some of these receivers have been in distributor stock for up to five years after the original date of manufacture. The receivers themselves are in perfect condition, but what can cause problems with many of them is aging of the oscillator components. Unlike the newer GT+, UT+, and M12 receivers, the VP used a "pendulum oscillator" that was much more complicated to stabilize than the newer units. During the board manufacturing process the oscillator on every board is characterized, and the appropriate oscillator characteristics are stored in EEPROM. The next time the board is powered on (usually by you) the oscillator characteristics are downloaded from EEPROM during initialization and used to set the oscillator output frequency. THE REAL WORLD - OK, that sounds great. What's the problem? Well, normally this all works fine, but what can slow things down is if the receiver has been sitting around for a while in an un -powered state. In this case, when the receiver is powered up, the stored oscillator characteristics are all wrong, the receiver runs off frequency, and as a result it cannot acquire satellites. [Art - also see Motorola VP Oncore Service Note] This will continue for some time (an hour or more in some cases) as the receiver tries to lock onto satellite carriers: searching for SVs, adjusting oscillator frequency, etc. Finally, the receiver hits on the right combination and BANG, things ret urn to normal. This is best illustrated with the following graph. This graph shows the start-up progression of an old 6 channel VP that has been sitting in a box since 1995. The receiver was initialized using our SynTAC control program, which initialized the receiver and loaded in correct time and position at time "0". Note that the receiver variously tracks 0, 1, 2, or 3 SVs for approxima
Re: [time-nuts] Looking for HP GPS splitter board
Hi John, Many years ago we supplied a number of these HP 2 and 4 channel PC assemblies to TAPR. I believe that Steve Bible also received some of these directly from us. Art -Original Message- From: time-nuts On Behalf Of John Ackermann N8UR Sent: Thursday, January 30, 2020 7:52 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Looking for HP GPS splitter board This is a long shot, but... A long while ago TAPR obtained and then sold some printed circuit boards that were intended to go into HP GPS antenna splitters. The boards were about 1.5 by 3.5 inches and had all the parts mounted for a 4 port splitter, but with no connectors attached. The part number on the board was 58516-60001, Rev. G. I would dearly like to find one or two of these boards to use in a project. If anyone has any they are willing to sell, please contact me off list. Thanks! John jra at febo dot com ___ time-nuts mailing list -- time-nuts@lists.febo.com 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%7Caf397685a3dc41edfc8608d7a59c700c%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1&sdata=5ZBwRq%2FilMSHT273fO7Z5Jy4JdGb9UNI3%2FERtw9yRFg%3D&reserved=0 and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Sawtooth correction
Hi, We have a TM1 Eval Kit with User's Guide. It has not been powered on for about 13 years. We'll check it out this week to see if it's operational. Art -Original Message- From: time-nuts On Behalf Of Jerry via time-nuts Sent: Wednesday, July 10, 2019 9:03 PM To: time-nuts@lists.febo.com Cc: gsteinb...@aol.com Subject: [time-nuts] Sawtooth correction Recent postings on 'sawtooth' hardware correction; several years ago SigNav Australia (no longer is business) had a timing product called TM3-02 that claimed to "Eliminate sawtooth correction" via some technology they had developed. https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fweb.archive.org%2Fweb%2F20091123094332%2Fhttp%3A%2F%2Fwww.signav.com.au%2F&data=01%7C01%7Cart%40synergy-gps.com%7Cf0a6ce1359cb439c035a08d705be9fa6%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1&sdata=7C4hAeLzeJGdN1WAQ3WxdmyIZVtZka4svBC54IPSrnk%3D&reserved=0 https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fweb.archive.org%2Fweb%2F20091013133934%2Fhttp%3A%2F%2Fwww.signav.com.au%2Ffiles%2Fbrochures%2FBrochure%2520TM3-02%2520module.pdf&data=01%7C01%7Cart%40synergy-gps.com%7Cf0a6ce1359cb439c035a08d705be9fa6%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1&sdata=A5mE8BMY%2BEgY5d3S3AO8n3z%2BR0XJz%2FSlG2ZpP150eu8%3D&reserved=0 Any of our Australian contingent remenber this company? Did anyone on the list test one of these things? I belive Synergy was a US distributor - maybe Art can chime in with some details. Jerry ___ time-nuts mailing list -- time-nuts@lists.febo.com 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%7Cf0a6ce1359cb439c035a08d705be9fa6%7Cc81f9fdec0e04d8c95779afaa0cad9ed%7C1&sdata=cpsI2kXAAqx8WLdNj6fCL16VAzOOyyIfrH0RKNSi5IE%3D&reserved=0 and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
Re: [time-nuts] Z3801A going into Holdover
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 On Behalf Of Mark Sims Sent: Thursday, June 20, 2019 7:25 PM To: time-nuts@lists.febo.com 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 -- time-nuts@lists.febo.com 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 -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
