At 08:27 AM 9/8/00 +0100, Peter Chadwick wrote:
>
>I'll ask again:
>
>What is the standard TL922 parasitic suppressor?
>
>If it's the usual carbon resistor/shunt inductor, I could well imagine
>parasitics starting after a period, as the resistor has probably got cooked.
>Especially when we take into account Tom's comments on seal temperatures - I
>presume he has evidence for that, or he wouldn't have said it.
Thank you, Peter! At last the discussion moves forward. Given how long
any given TL-922 may have been around, it seems entirely plausible to me
that the suppressor resistors would have changed value enough to permit
instability. Isn't it also plausible that faced with an unstable amp, the
average user might do things, like sweeping the tuning controls at full
power, that would inadvertently cause damage through arcing?
I have an SB-220 that has never been anything but stable. Nevertheless, I
can make it arc the tuning capacitor on 15M, repeatably, by simply turning
the loading cap to the full counter-clockwise position and closing the key.
Needless to say, I try not to do that!
73, Pete Smith N4ZR
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