[time-nuts] Re: Current-day GPS timing receivers

[Bob kb8tq]

Hi

> On Feb 19, 2022, at 6:59 PM, Larry Gadallah <lgadallah at gmail.com> wrote:
> 
> After poring over the several valuable references people have posted
> here, it seems that even the common commercial GPSDOs have
> implementation problems, so it seems like there's no (financially
> viable) off the shelf solution.

The “typical” commercial GPSDO ( regardless of who made it and for whom) 
is the result of years of work and some very exotic verification gear. If indeed 
the goal is to do “much better than” what is commercially available, just the 
cost of the test bench will be pretty amazing ( like > $100K .. at “eBay” prices 
 …. yikes …. ). 

Bob


> 
> It would indeed be convenient to have a kit option, but I'd image the
> potential marked for a GPSDO kit is vanishingly small.
> 
> FWIW, I started with a VE2ZAZ board and an Isotemp OCXO and a Motorola
> receiver of questionable provenance. Since then I've gathered an HP
> 10811D and I have an HP E1938A coming (I think), so I have only so far
> gathered some essential components that I hope are competent.
> 
> On Sat, 19 Feb 2022 at 07:13, Bob kb8tq <kb8tq at n1k.org> wrote:
>> 
>> Hi
>> 
>> Building a kit is very different than a from scratch design. A
>> Heathkit (to extend the years ago ham radio analogy) radio
>> was an option when you shopped for your Drake. Building it
>> would give you some experience.
>> 
>> The Heathkit *design* was done for you and all the complicated
>> higher level stuff was worked out / tested out / reworked / retested
>> by somebody else. As long as you put it together correctly, it
>> worked and was a good radio.
>> 
>> These days there aren’t a lot of folks selling kit GPSDO’s. Even
>> the kit radio business isn’t what it once was. “I’m going to do
>> a GPSDO” these days generally means a scratch design.
>> 
>> Bob
>> 
>>> On Feb 19, 2022, at 2:41 AM, Bill Beam <wbeam at gci.net> wrote:
>>> 
>>> But there is a magazine article....
>>> <https://www.qsl.net/n9zia/wireless/QST_GPS.pdf>
>>> By Brooks Shera, W5OJM.  QST July, 1998.
>>> 
>>> Following this article I built my unit in 1998 using his PCB and a Motorola UT+.
>>> It has been running almost continuously since then - almost 25 years.
>>> It has been thru several HP 10811 and 10844 oscillators during that time.
>>> 
>>> Even though Brooks is SK his GPSDO is still running.
>>> 
>>> Regards.
>>> Bill, NL7F
> 
> -- 
> Larry Gadallah, lgadallah AT gmail DOT com
> PGP Sig: 4E5A 6A79 0A8D 2C0D 8D20  609D 3681 AA38 09C0 8303
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com -- To unsubscribe send an email to time-nuts-leave at lists.febo.com
> To unsubscribe, go to and follow the instructions there.