[time-nuts] Restoration of 5065A - continued...

Bob kb8tq kb8tq at n1k.org
Mon Sep 11 16:12:09 EDT 2017


Well if people are looking for those willing to “adopt” a stray 5065A or two, I’ll certainly toss my name onto 
that list !! :) 

Back in the era HP did these designs, things like surface mount were still a bit new. They had some
very legitimate questions about packaging and published a few papers outlining them. On something 
like a frequency standard, they likely were even more conservative than on something like an entry 
level DVM. 

Without looking at the schematic for a while it’s a bit hard to guess what all might be done. On other projects
people seem to have looked at multiple boards as targets for rework. Certainly things like per card zener 
regulators are a target. There are a *lot* of three terminal regulators out there …..


> On Sep 11, 2017, at 2:22 PM, Ulf Kylenfall via time-nuts <time-nuts at febo.com> wrote:
> When I mentioned redesign, it was the intention to copy the by HP updated designinto a new Cad project (I use Cadence PCB Editor for which I have a license)and then accomodate for more modern versions of the operationalamplifiers since I guess that there are not that many "A7" modulesaround as surplus. Even HP used DIP-versions in the updated design.
> Today, I was offered a partially scrapped 5065A for parts.The XO is gone but the Rubidium tube is there, (most likely brokenTX heater). I have no idea of how old this unit is, but perhaps some modules in itare more modern than the ones in mine.
> I would have loved to get my hands on a modern/late unit and do the Edmund-Opticsfilter installation (Super 5065A) as referenced here. Some yearsago there were one up for sale at a reasonable fixed price. I hesitatedand -  "kazing" - it was gone.
> I have so far replaced the 709's with 741's and removed the frequencycompensation components (I did that already yesterday). 
> BR
> Ulf Kylenfall  SM6GXV
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