Bob Macklin macklinbob at msn.com
Thu Feb 14 22:15:49 EST 2008

```When you run over 25% carrier power but only modulate to the 1500W PEP limit
you do not produce as much audio power at the receiving end as you if you
run the 375W of carrier and modulate it to the 1500W PEP Limit.

Bob Macklin
K5MYJ
Seattle, Wa,
"Real Radios Glow in the Dark"

----- Original Message -----
From: "Jim Candela" <jcandela at prodigy.net>
Sent: Thursday, February 14, 2008 7:01 PM
Subject: [AMRadio] RE: MODULATION POWER REQUIRED

>
>
> John, and Group,
>
> Your PEP definition agrees with references from other sources. My math
> is a little weak, but doesn't this suggest that the 375 watt carrier
> limit we arbitrarily impose on ourselves is a low ball value, and with
> the definition below can't we run more carrier at 100% modulation and
> still meet the 1500 watt PEP output limitation? I seem to recall that
> Don, K4KYV had some pretty persuasive arguments countering the
> presumption we adopted years ago. This was back when the 1000W DC input
> "Grandfather Rule" was expiring for AM.
>
>
> 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)
>
>
> http://www.vk1od.net/VSWR/W4.htm
> Peak Envelope Power 'pX' (s1.157) means the average power supplied to
> the antenna transmission line by a transmitter during one radiofrequency
> cycle at the crest of the modulation envelope taken under normal
> operating conditions.
>
> John, WA5BXO said:
> For PEP it should read:
> "Well, PEP is defined as the AVERAGE power over at least one RF cycle at
> the most powerful point of the envelope."
>
> 73,
> Jim
> WD5JKO
>
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