The RMS power of an RF signal is a mathamatical approximation of the
equivilant amount of DC power.
For example, if an RF signal were to dissapate in a resistive load then the
RMS value of that signal would model the amount of DC power needed to cause
the same amount of heating in the load.
I don't quite understand what PEP is supposed to be but according to
http://www.its.bldrdoc.gov/fs-1037/dir-027/_3903.htm
peak envelope power (of a radio transmitter) [PEP, pX, PX]: The average
power supplied to the antenna transmission line by a transmitter during one
radio frequency cycle at the crest of the modulation envelope taken under
normal operating conditions. [NTIA] [RR] (188)
JoeD
N2UF
----- Original Message -----
From: <wb8jkr@juno.com>
To: <Maximo.Martin@icm.siemens.com>
Cc: <amps@contesting.com>
Sent: Thursday, November 07, 2002 1:25 PM
Subject: Re: [Amps] RMS-PEP & 2x8877
>
> The negative peak occurs 180 degrees away from the positive
> peak, so they don't occur at the same time. You can't add them
> together.
> PEP power is the same power level as you would have KEY DOWN
> at a given power level except whatever little extra you'd obtain
> from power supply dynamics, typically 5 to 10 %.
> A amp that runs 1000 watts output carrier is going to run 1000
> watts PEP output plus maybe 5 to 10 % during SSB use, its
> the average power that is going to vary considerably.
>
> Mark WB8JKR
>
>
> On Thu, 7 Nov 2002 10:20:59 -0500 "Martin, Maximo"
> <Maximo.Martin@icm.siemens.com> writes:
> > RMS is an average measurement, efective power instead PEP, it's peak
> > to
> > peak.
> > If you take one peak without flat-topping you have the RMS, but it
> > is from
> > the half of the total, in a graphic you use only the upper half part
> > of the
> > signal, but PEP is from the top peak to the bottom peak so it is
> > more than
> > double, it is 2.25 times.
> >
> > Max.
> >
> >
> >
> > -----Original Message-----
> > From: DF3KV@aol.com [mailto:DF3KV@aol.com]
> > Sent: Thursday, November 07, 2002 9:52 AM
> > To: Maximo.Martin@icm.siemens.com; amps@contesting.com
> > Subject: Re: [Amps] RMS-PEP & 2x8877
> >
> >
> > I
> >
> >
> >
> >
> > 2 x 8877 are able to run about 4.5 to 5 Kw out, but this is a RMS
> > measurement. The PEP value is the RMS x 2.25 so; 4.5 x 2.25= + 10000
> > W
> >
> > Max.
> >
> >
> >
> >
> > Hello Max,
> >
> > Please explain why PEP should equal 2,25 x RMS wattage?
> >
> > For my knowledge so far PEP ist the RMS wattage at the peak of the
> > envelope without flat-topping.
> >
> > 73
> > Peter
> >
> >
> >
> >
> >
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