At 04.44 1997-12-17 -0800, you wrote:
>... ... ...
>>I suspect that varying the ratio of screen volts to grid volts on the
>>G2DAF may well get the 3/2 power curve due to each grid down to a square
>>law for the overall transfer characteristic, although I admit I haven't
>>tried doing a mathematical analysis yet.
>
>If the screen potential was being varied at an RF rate, maybe something
>of the sort would be possible. However, in the G2DAF circuit, the screen
>potential is varied at a semi-audio rate while the grid is varied at an
>RF rate - so never the twain shall be in phase.
>>
>>The original idea of the G2DAF was to simplify matters by getting rid of
>>the screen and bias supplies. However, better linearity might be
>>available if some bias is available.
* I doubt that, as G2DAF is designed for zero-bias operation. That means that
* the amp will draw some amount of gridcurrent at all levels of drive.
* Taking this facts into account, I really don`t understand the "on-air-test"
* made by Rich. How could you possible lower the drive until there were no
* gridcurrent??
>Indeed, Peter, and a constant screen potential could well result in even
>better linearity. . IMO, the original G2DAF proposal also included the
>promise of Class-C-like efficiencies. .
>- . When I was a teenager, I saw advertisements in Popular Mechanics
>for plans for constructing more efficient carburetors for use in ordinary
>automobile engines. Claims of over 100MPG were pretty common. There
>were also advertisements for plans for constructing various and sundry
>perpetual motion machines.
>... ... ...
>cheers
>Rich...
* As said before, I really do like your sense of humour Rich!
* However, regarding efficiency, the resting Ip in a G2DAF amp is very low
and * much lower than amps in AB1 or AB2 = Higher efficiency for G2DAF!!
73`s Lars
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