K2 #4283 has been on the air for a couple days or so.
I thought I'd pass on something that might help others. After bolting on
the heatsink (the bottom rear part of the case) to Q7 and Q8, the manual
says to check that the collectors are not shorted to the case. Mine
were. I had the heatsink on and off quite a few times trying to find the
problem. Everything looked fine, but as soon as I would tighten the
screws the short would reappear.
I finally noticed that the four holes (for Q7, Q8 and the 2D fastener)
had burrs around their edges from when they were drilled. When I would
tighten the screws, the burrs would get pushed up inside the hole in the
transistors, causing the short. Removal of the burrs solved the problem.
--
73, Brian
VE7NGR
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