WT8R wrote:
> A friend of mine owned an AL-80A. He told me that the inductance in both
> the
> anode RF Choke and the filament choke were insufficient. He rewound both
> of
> these adding turns in each instance and more ferrite rod before solving
> the problems.
That's about the silliest thing I've ever heard!
The inductance of the filament choke has absolutely nothing to do
with tube heating at all! If it is too low, the tube simply can't be
driven properly.
With the plate choke, the only problem would be an increase in
tank Q on 160 meters.
The plate choke is self-resonant on 11 meters CB, and was
intentionally made that way. Maybe your friend was using the
amplifier on CB?
> The lack of sufficient inductance in the filament choke caused the tube to
> dissipate too much heat in the anode even when at idle.
Pure nonsense.
> Apparently the bias voltage was incorrectly dimensioned for proper
> operation.
Nonsense again. The bias sets the current at 1/2 the rated
dissipation.
Nice try Dave.
73, Tom W8JI
w8ji@contesting.com
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