[time-nuts] Noisy Sulzer 2.5 - Suggestions?

Ed Palmer ed_palmer at sasktel.net
Wed Aug 17 16:25:03 EDT 2016

I picked up a Sulzer 2.5 (not 2.5A or 2.5B or 2.5C) oscillator and 5P 
power supply.  It's working, but the AlDev at low tau is poor. After a 
few days of operation the AlDev @ 1sec. is only 1e-10.  It's not the 
power supply.  I'm running under 'AC fail' conditions with a lab power 
supply standing in for the batteries.  This bypasses almost everything 
in the power supply.  Eventually, I plan to replace the batteries with 
lead-acid and replace the circuit board with an improved circuit.

So, I'll be opening up the oscillator to see what's what.  My first 
'usual suspect' will be the Ta capacitors, but I'm wondering about all 
those carbon composition resistors.  Should I be looking at a wholesale 
replacement with metal film?  Maybe just in the oscillator and AVC 
areas?  Are there any other known trouble spots with these oscillators?

I haven't been able to find any info on the 2.5.  The manuals and 
schematics for the 5A and the 2.5B/C are some help, but the 2.5 is very 
different from the 2.5B/C.  Any info would be greatly appreciated.



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