COLIN LAMB wrote:
>
> The Heising choke is perfect for using a parallel 815m driven by a 2A3, to
> AM modulate an HY-69. You can get up to 80% modulation as is. By placing
> a resistor (and bypass capacitor) in series with the HY-69, you can reach
> 100% modulation.
>
> Be sure to remember to install a fresh bias cell before firing up.
Why would you want to use a UHF tetrode like the 815 as a modulator? You could
use it for a 112 Mc final. A pair of modern 6L6's could easily make enough suds
for high-level plate modulation of an HY69.
And it's a condenser, not a capacitor.
Vic K2VCO
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