"Timo Pohjola" <oh1mdr@saunalahti.fi> says --
> I was tuning my AL82 amplifier on 17 meter band and the plate choke
> blew. I haven't used the amp much before on 17m.
>
> Has anybody else had such problems? This was the first problem ever with
> this amp during 6 years.
Spurious resonances on plate chokes are not uncommon. There was a very
famous mod to Alphas some years back that involved moving the plate choke
resonance to the center of 11 meters (27.185 MHz).
It was roughly akin to wiring a frequency-sensitive stick of dynamite
inside a transmitter, as you discovered.
My opinion of this modification was that it constituted an actionable
violation of the US Communications Act of 1934 prohibition on sabotage of a
radio station, which predated the outlawing of amplifiers in the US
Citizens Band by nearly half a century.
Locally we have a law that's referred to as "reckless endangerment," which
could be used to prosecute people performing the mod in question.
Best bet? Rewind or replace in kind, and dip/adjust the replacement to
ensure no stray resonances fall in your bands of interest.
Tom, care to put in your 2c on this?
Jim N6OTQ
|