>
>> >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?
>
>SWR error is minimized if you know how to use the meter Rich.
? We are measuring power into a 50-ohm termination, Tom.
>
>You read reflected power near full scale using the proper slug, and
>subtract reflected power from forward. The result is the actual
>power keeping in mind the directivity error of the slug and the
>calibration errors.
>
? I don't believe that its all that simple.
>> >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?
>
>Yes.
>
? and?
Rich...
R. L. Measures, 805-386-3734, AG6K, www.vcnet.com/measures
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