[Elecraft] KPA-100 Heat Sink Compound

[Jim Wiley]

Gang -


When assembling the KPA-100, is it permissible to use standard 
zinc-oxide filled heat sink grease and mica insulating washers in place 
of the supplied silicon-rubber washers?  It seems to me that the grease 
option wouldn't require re-torquing because any "flow" would happen 
immediately when the transistors are snugged down to the heat sink.  


I've got lots of mica washers for TO220 size transistors that would seem 
to be about the right size.  I might need to do a bit of trimming for a 
better fit, but I've got lots of them.  Many times TO220's are used on a 
PCB just standing up in air, thus the leftover mounting hardware. 


Yes, the grease can be a bit messy, but I've been using it for years 
(with other projects of course), and never had a failure.  You don't 
need much per applications, either.  A 5-ounce tube of Dow-Corning 340 
purchased 20 years ago is still more than half  full, even after lots of 
home-brew projects. 


What say all? 



- Jim, KL7CC