[time-nuts] I've designed a GPSDO, but how "good" is it?

Charles Steinmetz csteinmetz at yandex.com
Wed Aug 19 01:22:38 EDT 2015

Nick wrote:

>Well, that all puts the nail in the coffin, then. If better ones are 
>cheaper, then I am wasting my time. I don't know how I missed them 
>when I was searching for one a few weeks ago. All I found were 
>manufactures not listing actual prices and eBay listings for used ones.

I did not mean to suggest that all of the GPSDOs I listed are 
new.  The first two are newly manufactured (although the second one 
contains a surplus OCXO).  The third and fourth are used surplus 
units (I do not count that against them -- arguably the best 
time-nuts GPSDO of all time is the Trimble Thunderbolt.  TBolts were 
readily available as surplus ten years ago, but are scarce and 
expensive these days).  The last one on the list is surplus, but the 
units currently available were never commissioned -- they are brand 
new in the original packing.

I wasn't trying to kill the project, just to give some 
perspective.  Depending on your primary interest (learning about 
oscillator disciplining, or selling gizmos with short development 
cycles), there is still much to be learned if you persevere -- and 
the possibility exists that several dozen revisions down the road you 
may have a gizmo that *does* justify being offered for sale.  The 
particular design issues related to GPS disciplining just do not lend 
themselves to a quick learning and development curve.

Best regards,


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