My SB220 occasionally has an audible HT short, consisting of a single
pulse, very intermittent, possibly not for a month or three at a time
and always when the rig is not key-down. And only in SSB mode. I've
never been able to visually see the short and I can't see any arc
tracks.
All of the HT diodes are 2N5408's and the caps have been replaced. The
HT reads 2800 V off 220 V mains and drops to around 2200-2300 key-down
max steam.
A blue wire leaves the HT transformer and runs in contact along the
chassis to one side of the capacitor bank, I have wondered if this is
breaking down beacause an arc here would not be visible with the covers
on.
What should I look for?
Thanks,
Ian ZS6BTE
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