[time-nuts] HP10811 losing EFC

[Neville Michie]

Hi,

I have two HP10811 oscillators that do not respond to EFC voltage.
The latest to fail had been quite accurately set against a TBOLT,
one morning (after being on standby in a HP5328A) it was off frequency
and would not shift with EFC but would adjust with the coarse adjust.
I have bought in two Phillips varicap diodes, BBY40 and BB149A,
but before I did some damage fault finding in the HP10811s  I thought
it wise to ask for any advice that was available.
While I am playing with them I may try to readjust the temperature  
setting
of the oven to get on top of the turnover. Can anyone point me to  
that article?

cheers, Neville Michie