R: [AMPS] Watt meters and PEP

[measures]

>
>measures wrote:
>>>>With a 50-ohm load, 387.3v-peak indicates 1500w PEP on the wattmeters the 
>>>>FCC uses. 
>>>
>>>Yes, obviously. There is nothing wrong with that "v-pk" calculation.
>>>
>>>What I cannot believe is that the FCC make any use of the quantity that
>>>you call "w-pk".
>>>
>>They don't call it that, 
>
>More to the point, they don't mention, consider or use your "w-pk" at
>all.
>
>>but this is essentially how one calibrates such 
>>a meter.  When one measures 387.3v-pk across a 50-ohm load with an 
>>NBS-traceable oscilloscope and multiplier-probe, the "PEP" meter is adj. 
>>to read 1500w.  
>>
>It's one way to calibrate a power meter, but not a good one.
>
>Guess how oscilloscopes are calibrated at RF? 

> By measuring the voltage
>across a line connected to a calibrated power meter! 

  .  hardly a good guess.   

> In other words, you
>improve the error budget by calibrating one power meter directly from
>another.

I worked in calibration laboratories for a total of roughly 10 years.  I 
repaired and calibrated oscilloscopes.  I do not need to guess how 
oscilloscopes are calibrated.    
>
 cheers, Ian. 

-  Rich..., 805.386.3734, www.vcnet.com/measures.  


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