[AMRadio] Too much HV

[Todd, KA1KAQ]

Hi Jim -

My issue involved 872As in the big rig arcing over and taking out
fuses, etc. The transmitter has a built in time delay to prevent
applying HV too soon on power up, aside from a rig that has set for a
loooooong time. I'd always let it idle for a good half hour if it had
been off for an extended period of weeks or months.

Swapped them out about a decade ago with 4B32s and nary a zorch since.
MV tubes work just fine when they're new. It's as if they hit some age
limit and start to act up. Like the stories about teenagers.

~ Todd,  KA1KAQ/4

On Tue, Nov 15, 2011 at 9:53 PM, James Liles <james.liles at comcast.net> wrote:
> Hi Todd:
> The 866 needs to be warmed up to vaporize the mercury or they will ARC over.
> Maybe too fast on the HV switch.