[AMPS] PEP philosophy

[Steve Thompson]

-----Original Message-----
From: rb <rbigg@pcola.gulf.net>
To: amps@contesting.com <amps@contesting.com>
Date: 06 January 2000 21:23
Subject: [AMPS] PEP philosophy


>
>Lu wrote:
>
><For the FCC PEP rule, Part 97.3 defines PEP as "The
average power supplied
>to the antenna transmission line by a transmitter during
one RF cycle at the
>crest of the modulation envelope taken under normal
operating conditions.">
>and


The same wording is used in the UK licence - I guess it is
an internationally agreed form of words that covers all
situations.

>
><To me there has to be 2 or
>more values in order for an average to be relevant.  A
point (eg., a peak)
>is only 1 and if they (the writers of the rule) were in
fact referring to a
>peak then they would have left out the reference to
average.>
>
>Sure gotta agree with you on that one.  If the FCC rule
quote is correct,
>then your comment is too.  The FCC quote is a logical
inconsistency.  This
>is a little nit-picky, but that's what we're doing in this
discussion
>anyway.  There can't be an average when we're talking about
moving time
>lines, and one singular point value is taken.


They are talking about the average power delivered by one
cycle of rf. The rf voltage at the fundamental frequency is
a sinewave. During the rf cycle, the power goes from zero to
a peak, back to zero, another peak (from the negative half
of the sinewave) and back to zero again. Mathematically, you
integrate the varying power over the cycle to get an average
value. In simple terms, it's the amount of heat that the
load dissipates.

For the PEP measurement you choose the point where the
envelope of your rf signal is maximum, and look at one cycle
of rf at that point. Of course you don't actually do that in
practice, it's just a way of defining things without
loopholes.

Hope this helps.

Steve


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