>
>
>--- Lamb <k7fm@teleport.com> wrote:
>> Very few tubes have published screen voltage curves
>> showing what happens
>> when you change screen voltage on a particular tube.
>
>I'm glad I'm not the only one experiencing difficulty
>in finding data. :-)
>
>> The very few curves that are published lead me to
>> conclude that varying
>> screen voltage within a range of 25% to 100% of
>> maximum will be fine, with
>> the understanding that gain will increase as screen
>> voltage is increased.
>> When the screen voltage is run below 10% of rated
>> maximum voltage, strange
>> things can happen. I would be very concerned about
>> distortion products and
>> other undesireable characteristics under those
>> conditions.
>
>I guess I never intended to drop to a level as low as
>10%. I was more interested in the effect of the
>scenario where I decided to run it class C for some
>hi-power CW operation
// Class C will not make a solid-state exciter very happy.
> or something but left the screen
>volts at the AB1 level. ( 750 V as opposed to dropping
>it to 400 ) If the only difference is higher gain....
>that doesn't sound all that bad to me :-).
>
// The power output is roughly proportional to the ratio of screen
potentials raised to the 1.5 power. Thus, doubling the screen V makes
roughly 4.5db difference in output.
>...
- R. L. Measures, 805.386.3734,AG6K, www.vcnet.com/measures.
end
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