Ummm, no... Thought didn't occur... I will do that but I unlikely I
will make a change...
One resistor got hot in the middle of the winding, bubbled the coating
over a distance of about an inch and a half, being exposed to the air
oxidized the nichrome wire and it finally burned in two... Then the
fireworks started with crap being arc sputtered all over the PS...
Being the RF box is in a different room of the shop than the radios, I
heard/noticed nothing until I happened to idly look the HV while in
receive... Eyes got wide and I hastily hit the main breaker on the
wall by my left hand (planned that way for stuff such as this) The
other 4 resistors look fine, no sign of overheating... I am going to
change out the whole rack of 5, but that is just because I'm an old
woman about minor things - spent part of my wasted youth maintaining a
herd of 100KW RF generators and a pinch of prevention stops a whole
bunch of lost production time...
It looks to me to be a manufacturing defect in the resistor as opposed
to deficient design... ( Brand was HEI 9352, possibly a spot welded
wire join in the winding? - dunno. )
I know contesting groupies go on about Henry's supposed design
deficiencies, but I have to say until this incident this amp has given
a dozen years of solid contesting service... The high voltage
stabilization is/was stiff... Since I don't jump from band to band in
a contest the slow tuning is not an issue... I have been happy with it...
denny / k8do
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Denny == Have you checked the max V rating of Ohmite's 100W resistors?
