Sheesh!
Roy K6XK
> Roy says:
>
> >delivers an accurate peak DC voltage representation of the
corresponding
> >RMS power at the dummy load.
>
> Doesn't contact potential of the 6AL5 affect the accuracy? The problem
with the
> voltage and current measurement schemes is that the error is squared,
so a 3%
> error in measurement gives a 6% error in the final answer. Then
there's mismatch
> errors to consider, plus the question of the actual load impedance.
For
> instance, using a 52 ohm load and assuming a 50 ohm load is a 4%
error. A 1.02:1
> SWR can give 2% error. Flatness in the detector is another possible
problem.
> Let's assume it's flat to 0.05dB, and there's another 1.2% error. My
HP
> catalogue lists various of their solid state detectors as 0.2dB/octave
from
> 10MHz up to 1 GHz, so my 0.05dB may be a bit hopeful......
>
> Not that it really matters in many ways, except for calculating PA
efficiency.
> In the final analysis, it's really 'Did he come back to me?'
>
> 73
>
> Peter G3RZP
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