R: [AMPS] Watt meters and PEP

[Ian White, G3SEK]

Rich Measures wrote:
>>Although many wattmeters do use diode detectors, they do not
>>calculate the power directly from the rectified voltage. Instead they
>>are calibrated from other wattmeters whose calibrations are ultimately
>>traceable to thermal standards.
>>
>For PEP measurement?

The calibrations are done on CW, ie under steady-state conditions.

A "peak reading" power meter displays the highest value of the rectified
voltage - in other words it senses the peak of the modulation envelope,
to read PEP.

>>
>>Earlier, Rich Measures said:
>>>> ?  RMS is  equivalent DC heating ability.  For example, with a
>>>> sine-wave,
>>>> 200w-pk would have the heating ability of 100DC watts.  .
>>
>>This "200w-pk" is a peak instantaneous power. Peak instantaneous power
>>is a notion with very little physical meaning, and no practical use.
>>Ignore it - its only power is to confuse.
>>
>This is essentially how the FCC measures PEP.

I cannot believe that.

73 from Ian G3SEK          Editor, 'The VHF/UHF DX Book'
                          'In Practice' columnist for RadCom (RSGB)
                           http://www.ifwtech.demon.co.uk/g3sek

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