[time-nuts] Temex rubidium

iovane at inwind.it iovane at inwind.it
Sun Feb 3 20:07:52 EST 2008


Brian,

your problem sounds different of mine. Anyway, what I wanted to mean is that
the control voltage is monitored not actually at the varactor, but much more near to 
the sweeping circuit. That indication might be misleading because there are other 
components between the point where the voltage is measured and the varactor. 
Just to keep in mind during troubleshotting....
Good luck in reverse-engineering a multilayer pcboard.
All the best,
Antonio.

> Antonio-
> 
> You have a good point. In my case, the varactor voltage as read by
> the A to D shows "EF" which is very close to the "FF" max indicated
> in the manual.  If the temperature of the unit is warm or hot the
> unit will lock. But if at room temp or cold the unit will never
> reach a locked condition.
> 
> I have adjusted the freq trim settings both digital and analog
> and just cannot trim the unit any more. Over the past several years
> the unit has needed trim in one direction and so it is not
> unexpected.
> 
> This is a very compact unit and I'm hoping to find a schematic
> before I open it. Otherwise, I'll be drawing my own.
> 
> Thanks.
> 
> -Brian, WA1ZMS/4





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