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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