I recently got a rare HP 5065A Rubidium frequency (secondary) standard off Ebay (
https://www.eevblog.com/forum/buysellwanted/fs-(uk)-hp-5065a-rb-frequency-standard-other-calibrators/). This is one of the old time goodies.
It was a "For Parts" sale and the seller didn't give much info, but it was a rare opportunity to get one of these over in Europe and shipping from the States is a killer due to their weight. So it took my chances, expecting the worst and hoping for the best. The 5065A arrived this week and a first glance revealed that (one of) the previous owners was "Devonport Management Limited". Port? Do I hear sea port? Salt water? Yes, you guessed it, mild corrosion everywhere, but lets do an inventory first.
This is a rather recent 1989 model with all options (that is option 001 and 002). Option 001 is a clock module, which gives us a, well...uhm, clock, a 1 pps output and a sync input. This is a must have for anyone who can't stand it, when the integrated clock of your favourite data logger goes out of sync. Love it! I'll never miss a second for the rest of my life.
Option 002 is a NiCd backup battery which gives you 10 minutes of battery life for a whooping 16 h of charging. We will get to that later.
Being a more recent model it also features the better 10811-60109 OCXO. Very nice indeed.
I don't have a power cord yet, but that is something Mouser can fix. Meanwhile I opened it up and took a few pictures. Unfortunately half of them are still on the mobile phone of my colleagues, so I will post them later. The first thing I was greeted with, was a bag with “loose nuts and screws” written on it – bad sign. The rubidium cell was disconnected and the wires hanging loose. The battery was corroded and had spilled its guts – yuk. But otherwise at least everything seemed to be there. Nothing missing at first glance. The first picture shows the the inner assembly, from which I have removed the battery the A6 board and the rubidium cell. You can see some of the rust I was talking about on the oscillator housing in the right bottom corner.
I checked the boards and obviously someone already had a shot a repairing them. Man, I just love it when people leave the flux on the boards...Some of the boards have new caps on them, but no cleanup was done in the areas which had signs of capacitor leakage. I will post the pictures of the boards as soon as I get my hands on them. All the boards will require new caps and some thorough cleaning to get rid of the copper oxide.
What do you guys think is best? Citric acid or vinegar? Then some sodium bicarbonate (baking soda) to neutralize, distilled water and finally IPA. That would be my strategy and everything that is left will meet my friend, the fibreglass pen.