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[AMPS] RMS Power

To: <amps@contesting.com>
Subject: [AMPS] RMS Power
From: billydeanward@hotmail.com (Billy Ward)
Date: Thu, 28 Jun 2001 16:00:39 -0000
Yeah, I have no problem with what you are saying, but what Bill said about 
the audio industry inventing RMS has weight in that area.  However, I used 
the term RMS power before the big audio boom started--back in 1957 and when 
we novices were being taught by the older hams, the term was very much in 
use.  W6UGA--John Klingman of Manteca, Ca. (SK) was a very well known ham 
and K6BP Ray Fulton, also of Manteca, (SK) wrote articles for a number of 
the respected ham magazines.  They both used the term RMS power on a regular 
basis.

Ok, Bill, I know the standard way to derive RMS voltage. You take the square 
root of the sum of the squares of the individual voltages of each of the 360 
degrees of the sine-wave.  Now please show me how that is used in the power 
formula, as you mentioned, to come up with average power.  I am all for 
learning something in my old age.

Billy


>From: "Mike" <W4EF@dellroy.com>
>Reply-To: "Mike" <W4EF@dellroy.com>
>To: <amps@contesting.com>
>Subject: Re: [AMPS] RMS Power
To: <amps@contesting.com>
>Date: Thu, 28 Jun 2001 07:44:38 -0700
>
>Hi Bill,
>
>Isn't the RMS Power rating of an audio amp much lower than its
>peak output capability? When I was in high school drooling over
>high-end stereo amps, I recall magazines like Stereo Review would
>rate audio amplifiers in terms of their peak output capability
>as well as RMS output. The really good amps were capable of
>deliverying something like 3 or 4 times their RMS rating on music
>peaks without clipping. I think they used the term "dynamic
>headroom" when comparing RMS to peak output capability.
>
>Mike, W4EF............................................
>   ----- Original Message -----
>   From: William Fuqua
>   To: amps@contesting.com
>   Sent: Thursday, June 28, 2001 5:49 AM
>   Subject: Fwd: [AMPS] RMS Power
>
>
>           There is no mathematical notation for "RMS POWER".
>   If you calculate voltage from average power and load resistance you get 
>RMS volts.
>   Like wise if you calculate current from average power you get RMS amps.
>           Look at the definition of RMS voltage or current. Put it into 
>the equation for
>   Power.  What you get is the formula for Average Power!!!!!
>   This RMS power stuff started in the 60's with the stereo equipment 
>manufacturers.
>   They invented  "RMS Music Power".  This is equivalent to  PEP, low% duty 
>cycle power.
>   It allowed them to come up with large wattage ratings for short burst of 
>audio. This was necessary
>   due to the fact that their equipment had weak power supplies and low 
>power dissipation capability.
>
>   RMS power is a meaningless term.
>
>
>   73
>   Bill wa4lav
>
>
>
>
>
>
>     X-Originating-IP: [12.41.226.194]
>     From: "Billy Ward" <billydeanward@hotmail.com>
>     To: amps@contesting.com
>     Subject: [AMPS] RMS Power
To: <amps@contesting.com>
>     Date: Thu, 28 Jun 2001 05:32:16 -0000
>     X-OriginalArrivalTime: 28 Jun 2001 05:32:16.0893 (UTC) 
>FILETIME=[B175B2D0:01C0FF93]
>     Sender: owner-amps@contesting.com
>     X-Sponsor: W4AN, KM3T, N5KO & AD1C
>
>
>     [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
>
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