[time-nuts] Sulzer 5A Repair Notes

[AC0XU (Jim)]

Thanks to everyone who had a suggestion re replacing the broken fine frequency adjustment capacitor.

AFAIK, there are no glass trimmer caps still made that are the same size. By buying a large number of used/NOS trimmers on Ebay, I eventually found one the right diameter and close enough on length to work fine:

JFD VCJ1018

A few seconds with a hot air desolderer and the threaded end literally fell off, leaving the glass tube open at both ends, as required.

After reassembly, and a quick adjustment of the coarse trimmer, the 5A seems to be working o.k. 

One thing I noticed is that when heated up, the adjustment shaft gets much tighter than when cold. It is so tight that feeling when it is at the end of its normal range is difficult. My guess is that some previous user adjusted it too far and broke the capactitor.

I would be tempted to use some graphite lubricant except that having graphite bits floating around in the works doesn't seemlike a good idea...

Jim