Hi Marv,
The average voltage of a sine wave is 0. That is why the RMS value
is used in power calculations. For a sine wave the RMS voltage is
0.707 times the peak voltage.
73 de Mike, W4EF.........
----- Original Message -----
From: "Radio WC6W" <wc6w@juno.com>
To: <billydeanward@hotmail.com>; <amps@contesting.com>
Sent: Thursday, June 28, 2001 7:20 AM
Subject: Re: [AMPS] RMS Power
>
> On Thu, 28 Jun 2001 05:32:16 -0000 "Billy Ward"
> <billydeanward@hotmail.com> writes:
> >
> >[WC6W]
> >The Bird 43 (without a peak reading module) is an average reading
> >meter.
> >
> >[Billy]
> >I thought that the Bird 43 was an RMS meter without the peak reading
> >module.
> > RMS and average are not the same?
> >
> >Billy
> >
> >_________________________________________________________________
>
> Hi Billy,
> No, they usually aren't.
>
> For a sine wave, average voltage is equal to .9 * RMS voltage. The
> factor is different for other waveshapes. Try figuring the numbers on a
> triangle wave for... fun. :-)
>
> The Bird scale is calibrated to read "power" (RMS voltage squared /
> line R) even though it is driven by average voltage... accurate as long
> as it is measuring a sine wave in a 50 ohm resistive system as Maury
> noted.
>
> 73 & Good morning,
> Marv WC6W
>
>
>
>
>
>
>
>
> *
>
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