>> If you
>>think that he had a parasitic event while unkeyed, please explain how
>>this could happen. I always belived that a tube in cutoff would be very
>>hard to get oscillating. You also told me this once.
>>
>? The how part beats me. It has not happened to me, however, I have
>talked to a number of those who have had it happen. How do we know it
>was a parasite? Bent fil. helix / sudden change in suppressor resistance
>/ 6kV bandswitch arcs in amp. with 3kV anode supply, are clues.
I guess it happens to those who think that every bang is a parasitic
oscillation. For one, with proper suppressor resistors you shouldn't have an
oscillation. I don't think the oscillation changes the value of the resistors.
Rather, I think the resistor values change over time and over being heated up.
Then you can get an oscillation because of bad resistors and hence a
suppressor not performing properly.
But the only thing that blew in this guy's amp was a resistor. Don't think he
had the beloved parasite.
73,
Jon
KE9NA
--------------------------------------------------------------------------
Jon Ogden
jono@enteract.com
www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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