[Amps] Don't do this

[Vic K2VCO]

Having finally finished my 813 amp and put it into service, I took my SB-1000 to the bench 
to find out what had caused the loud ZZZZAAAP and blew the fuses last week.

I found that one of my clever mods was not so clever at all. I had decided that the tank 
coil was too close to the steel top cover, and this was reducing efficiency on 160 meters. 
So I moved the tank coil about 1/4" farther away from the cover.

I am not sure that it helped on 160. But it placed it closer to the plate choke. Turns out 
it was a little less than 1/4" away.

This worked fine for a long time. But last week I was trying to work something on 30 
meters and I wanted my full legal 200 watts instead of the measly 100 that comes from my 
K3. 3 dB could make the difference. Either the choke had a resonance that vaporized the 
wire which started the arc, or the small gap happened to be near a new hot spot on the 
choke, but ZAP.

Some of my happier mods were the addition of a glitch resistor and back-to-back 1N5408 
diodes across the meters, so nothing else was damaged. A new choke is on the way from RF 
Parts.
-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/