[time-nuts] Re: Z3801A GPS Rx board substitute?

[Lon Cottingham]

In response to  Dan Rae's post  about his "faithful 3801".

After 20+ years of constant service, my Z3801a developed a similar
problem.  At first, I also assumed
The Motorola GPS receiver to be the source of the problem.  To make a
long story short, the problem
turned out to be the double oven.  Apparently the internal thermostat
failed in the on position.  I did
notice  that the oven was unusually warm.  Changing out the oven
solved the problem.  Hope to get
 another 20 years service out of the "old girl".  Any comments on the
over- heating oven?

73 de Lon, K5JV




On Sat, Apr 9, 2022 at 12:27 AM Art Sepin <art at synergy-gps.com> wrote:
>
> 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 (art at 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 <aekalman at gmail.com>
> Sent: Friday, April 8, 2022 6:21 PM
> To: Discussion of precise time and frequency measurement <time-nuts at lists.febo.com>
> Subject: [time-nuts] Re: Z3801A GPS Rx board substitute?
>
> I pinged Art at oeminfo at 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 at 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
> >
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