Pardon my saying so Roy, but I think you may be confusing the issue
here. We all know that you understand this stuff backward and forward
and most here have the highest regard for your expertise, including
me. I also agree that you are totally correct in what you say.

The question was not what is the average power of a 100% modulated 4
watt carrier.
It was "is the 4 watt maximum power of a CB radio actually average
power, not RMS right?"

He is trying to establish the meaning between so called (widely
misused) RMS power and average. And he is also trying to figure out
the relationship to pep.

Although you did acknowledge that he has the correct conclusion to his
question, at the same time I think that you have injected some doubt
in your answer. There are a lot of people that have trouble with some
of the basics of this stuff. Throwing a little twist like that in
often raises the confusion level with some. Again pardon me for
comments.

73
Gary K4FMX


On Wed, 20 Oct 2004 13:17:49 -0700, Roy Lewallen
wrote:

The average power of a 100% modulated 4 watt carrier is 6 watts, not 4.
(If you want to look at it in the frequency domain, where the total
power has to be the same as in the time domain, you've now got the
original carrier plus two sidebands. The power in the two sidebands
totals 2 watts.) And I'd give the answer to Chris' two questions as yes.

Roy Lewallen, W7EL

Paul Burridge wrote:

On Wed, 20 Oct 2004 12:08:59 GMT, "Chris"
wrote:


Paul,

I've been following the thread still. Let me go back to the original
question for a moment. So is the 4W maximum power of a CB radio is actually
average power, not RMS, right? If it is modulated at 100% with a sine wave,
what wil the PEP be? Is 16W the correct answer?


AIUI the specified 4 Watts is the maximum*average* power allowed (in
the UK, anyway). When you modulate it 100% AM., it's still 4W average
power. If you fully modulate it with FM., it's *still* 4W average
power. But as you've seen here, for every assertion, there's a
contradiction. ;-)