[time-nuts] RACAL-DANA 1992 Option 04E problems

[Ed Palmer]

Are you sure that the OCXO is failing?  I bought two 1992s.  One was 
basically dead.  A custom IC (U39) was running at 90C with no heatsink.  
In the working unit U39 was ~60C.  One of this chip's functions is to 
process the oscillator before it's sent to the 10MHz STD. OUTPUT jack on 
the back.  U39 is the socketed 40 pin dip located on the right side, in 
front of the OCXO.  Maybe your unit has a flaky U39.

Ed

billh40 at aol.com wrote:
>           I own one RACAL-DANA 1992 (Standard- TCXO).  I purchased one with the Option 04E on eBAY.
>
>           The 04E chassis is sealed and the internal OCXO overheats due to lack of cooling air.  This causes the counter to stop taking measurements.  I had to add ventilation holes on the top and right side of the chassis lid to obtain reliable operation.
>
>           Both counters work up to 1,750 MHz.
>
> Bill Hanna
>
>  
>
>
> =
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>