Hello List
First experience with an AL-1200, received melted down filament wiring,
which made a mess of the wiring harness etc.
Had to disassemble the RF compartment, and foolishly did not record the
position of the neutralizing capacitor, which is a small copper strap
mounted to a standoff, and neutralizing capacitance is adjusted by the
position of the strap with relation to the tube.
I wonder if there is a way to adjust the capacitance with out constantly
taking off the lid, adjusting it a tiny amount, closing the amp,
powering the amp, and trying it again, and again, and again!
At first it went into oscillation on 10 AND 15 meters, adjustments
quickly tamed 15 meters, but 10 meters remains elusive.
I have read of a way to adjust it by disabling the PA and measuring pass
through power - but nothing in detail.
Precious little out there on the web - so I can go through dozens of
power cycles (poor tube!) or perhaps there is a way to position the
'neutralizing capacitor' in an more elegant, intelligent fashion?
any help appreciated!
73 Kevin K7ZS
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