>
>> >When the FCC measures power, they use a regular peak reading
>> >meter. .....
>>
>> ? wanna guess how such meters are ultimately calibrated?.
>
>No need to guess. Bird calibrates them on a caloric standard. Not
>a scope in sight.
? Peak reading instruments calibrated with a bomb-calorimeter?
>
>Now there is nothing wrong with using a scope, assuming you have
>one with the required accuracy and resolution and a good load, but
>it is not a good instrument for use in antenna system to measure
>power. Errors in power readings occur at both the square of the
>voltage reading error as well as proportional to load impedance
>error.
? and an ordinary wattmeter would not be subject to such errors, Tom?
>There is absolutely nothing wrong with using a good meter. A few
>people have wrongly assumed a storage system can't respond fast
>enough, but that is certainly not correct. The storage system has
>to track the envelope change rate that follows audio, not the RF
>cycle change rate. A meter with directional coupler also remains
>accurate over reasonable load impedance errors. You simply
>deduct reflected power from forward power.
>
? Can you explain why this is true?
>
- cheers, Tom
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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