... ... ...
>I would be very inclined to measure the IMD with W8JI's 3 tone test,
>with 2 of the tones about 40 or 50 Hz apart - that will show up any
>problems with the time constants in the SG circuit as well as in the HV
>PSU.
The G2DAF circuit's screen voltage remains constant during such tests.
However, with voice modulation, the screen voltage - and the IMD -
fluctuate wildly.
One of the more curious things I ran into with measuing the distortion of
DAF amplifiers on the air, is that DAF owners would reduce the grid drive
to prove that the DAF circuit was clean, and subsequently turn the wick
up after the test to increase power output.
Rich...
R. L. Measures, 805-386-3734, AG6K
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