[Amps] 6m amp repaired, thanks for the help

[Bill VanAlstyne W5WVO]

Finally, my 6m-converted SB-220 (which is now beginning to resemble a homebrew amplifier) is back in service -- after repairing the burned-out plate RF choke; replacing the welded-closed bias relay (along with its associated dropping and shunt resistors) with a faster and quieter reed relay; replacing the smoked bias diode string with bigger diodes; replacing the fractured rotary meter switch with a cool 3-position toggle switch; adding a B+ glitch resistor; and... guess what? The 3-500ZGs apparently emerged undamaged from this episode, and are both producing full output, very stable. In fact the amp feels more stable than before it blew up last month. Last thing I'm still planning to do is put a very fast 1A fuse (with 50K ohm shunt resistor) in the bias supply line, which will hopefully protect the diodes and relay contacts from future glitches.

Thanks to everybody whose suggestions and tutorials contributed to my learning and success with this project. It was fun.

Bill W5WVO