[AMPS] Watt meters and PEP

[Mike Sawyer]

This might be too simplistic (which I think it is but what the hell!). But
turning the "Wayback Machine" to the time I took basic electricity and
electronics in High School, I remember being taught that RMS is equal to
.707 X peak. Average is equal to .636 X peak. Knowing full well that RF
generates some "Funky" properties, it is still an AC sine wave. Am I correct
or did I take a wrong turn on my Megacycle??
Mike(y)
W3SLK
----- Original Message -----
From: Maurizio Panicara <i4jmy@iol.it>
To: Dave D'Epagnier <DAVED@ctilidar.com>; AMPS <amps@contesting.com>; 'Ian
White, G3SEK' <G3SEK@ifwtech.demon.co.uk>; 'measures' <measures@vcnet.com>
Sent: Thursday, January 13, 2000 4:48 PM
Subject: R: [AMPS] Watt meters and PEP


>
>
> Measuring a power through a voltage (or current) is an indirect way to
> estimate something we're not really measuring.
> A conventional power meter is not measuring a power but the voltage (or
> current) of a complex signal. In a complex AC it's correct to talk about
RMS
> as the closest equivalent.
> Evaluating RMS as .707 of the peak would be true with pure carrier sine
> waves but its very confortable to utilize the diodes and a suitable RC
time
> constant to rectify peak voltage as a DC level.
> Obviously, in a DC voltage the RMS and the AVG are coincident but this DC
is
> not existing beeing only created in the Wattmeter itself.
> All considered, a complex envelope like a modulated signal creates a big
> deal when approximations are not accepted.
>
> 73,
> Mauri I4JMY
>
>
>
> ----- Original Message -----
> From: Dave D'Epagnier <DAVED@ctilidar.com>
> To: Dave D'Epagnier <DAVED@ctilidar.com>; AMPS <amps@contesting.com>; 'Ian
> White, G3SEK' <G3SEK@ifwtech.demon.co.uk>; 'measures' <measures@vcnet.com>
> Sent: Thursday, January 13, 2000 7:57 PM
> Subject: RE: [AMPS] Watt meters and PEP
>
>
> >
> >
> > A 200w peak signal into a 1 ohm load would have a voltage amplitude of
> > 14.14volts. The average power would be Vrms squared / R or 100v/1ohm =
> > 100Watts. This is average power, which is the dc equivalent heating
> ability.
> > Power (unlike voltage or current) is always positive. There is no reason
> or
> > need to evaluate it's rms level.
> > ----------
> > From:  measures [SMTP:measures@vcnet.com]
> > Sent:  Thursday, January 13, 2000 10:18 AM
> > To:  Dave D'Epagnier; AMPS; 'Ian White, G3SEK'
> > Subject:  RE: [AMPS] Watt meters and PEP
> >
> >
> > ?  RMS is  equivalent DC heating ability.  For example, with a
> > sine-wave,
> > 200w-pk would have the heating ability of 100DC watts.  .
> >
> > cheers, Dave
> >
> > -  Rich..., 805.386.3734, www.vcnet.com/measures.
>
>
>
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