[BC] 5CX1500 Tubes - Recollection

[Dana Puopolo]

I replaced that whole SCR mess with two brass bolts (bypassed) and pulled the
card. Used the screen control to adjust power output and never had a problem
with that rig ever again! It ran as reliable as a refrigerator.

From: "John Lyles" <jtml at losalamos.com>

My experience with the old Collins 2.5 kW using the pentode and 310 exciter
was in the late 1970s, where I had to maintain one in VA that was hammered by
lightning. The big SCRs 
in the primary 220 VAC line were messed with, and so was the controller board
(burned traces). Somehow I managed to float an oscilloscope off ground (scary)
and probe the SCR gate drive while it was running. 
Don't touch that scope! Every so often, it would jump (the phasing of the
pulse) and the circuit breaker would pop open.