[time-nuts] HP quality... a HP5065A experience

Magnus Danielson magnus at rubidium.dyndns.org
Sat Sep 10 16:35:33 UTC 2011

Dear time-nuts,

As I am trying to bring a HP5065A back into operational mode, I have 
been looking at the Cell oven and Lamp oven readings, but it has been 
jump. While looking at it with a friend (a true soldering master) I 
popped the lower lid and he found that one of the wires was not 
soldered. Sure enough this was one of the taps from the A11 board for 
the front panel. It has been like this when it was assembled, so the HP 
quality checks didn't catch it.

I do beleive that the other end have the same problem, the selector 
switch shows the same unstable behaviour, but is harder to check. I have 
not yeat figured out how I pop the front end off so I can access the 
rotary switch properly.

So be aware of wires. A bad solder joint doesn't seem to be there, but 
lacking solder joints was a bit surprising.

I have trouble with this old beast, it does not lock so caring about 
basics like ovens and oscillator tunings has been my starter approach.
The rubidium Cell and Lamp ovens (pin 2 and 14) seems to stabilize at 
15,75 V rather than the 18 V which the manual indicates should be the 

I cannot honestly say I spent quality time on it yet. Hope to get up to 
speed on it.


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