Hi all,
I have bought from a friend a couple of Eimac 3500Z ( from 1989?) as
spare,
the owner says this tubes only have been in use two times he check them on a
Heathkit amp and they were good.
I have inserted them on my Drake L7 on CW mode and after less than a minute
being on SBY a BANG! And no HV.
A resistor in the PS was exploded; it was R12 (IRC type BWH .82 ohms 2W) I
had one of these resistors and after replace and putting back my old tubes
now the amp is Ok again.
There is not any visible anomaly on the tubes also a have check them with a
tester and tapping them, all OK, I have no Hi Pot.
Tomorrow I am going to try again but using a Mains variable trans former
starting with 100v mains and trying to cook them on SBY.
There is any problem with that? I will appreciate any help.
Best 73, Jaime.
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