Lou,
Tom was saying (I think) that Peak Envelope Power (PEP) is defined to be
the average power during one RF cycle at the peak of the modulation
envelope (usually audio frequency). As defined, PEP must reflect the RMS
value of the peak voltage attained at the crest of the modulation envelope.
This RMS value is meaningful because it refers to the time-varying
(sinusoidal) voltage at radio frequency, not the audio peak at which the
value is measured.
BTW, I agree. Why build an amplifier at all if it's not as big as possible.
73- John
KK5MH
At 08:30 AM 3/7/97 -0500, you wrote:
>Tom, mentioned in a response to my mathmatical attempt to prove that PEP
>power is twice the average power. In his response he made mention of the
>term PEAK RMS value. This is an ambiguous statement, and the two are not
>related. PEAK is PEAK and RMS is just what it implies (root mean square), and
>we simply can not argue that PEAK =1.414(RMS) so you cannot say PEAK RMS.
> Also Tom mentioned that peaks can reach as high as 7 to 1. If that was
>true, then Tom has figured a way of creating energy. At least that what it
>seems to me. If this were true, I would like to see the mathmatical
>explaination on how the 7 fold power element is derived. I think I made a
>fairly backed up by math statement of PEP versus average
>power. The power supplies in our amps can only provide a proportional value
>of its rating versus RF power output rating, and certainly we know it is not
>nearly a 1:1 transfer. And if 7 fold power peaks were true how can we
>determine how the power supply gave us this peak value on the input side? Am
>I missing something here? If so who can explain where I am misinformed. Also
>to change the subject, another gentlemen wanted us to get back on discussing
>amps, so I will reply to some other postings regarding amps....One gentleman
>asked where he can get parts specific to building up an amp with 811,s .
> Well, many parts that will work on 811 circuitry will work on circuitry
>using much better and higher output tubes. My suggestion in that regard would
>be dont waste parts on 811,s that can be used to build an amp using an 8877,
>or 4-1000 or any other tube that will produce some "burn a hole" in the
>frequency power! I could never figure out why anybody would build an amp
>(homebrew) using a single 3-500 (for example) when it would be just as easy
>to add a second tube. Hey lets talk power here! RIGHT! Our contest group has
>built some mighty fine looking vhf amps using 4-250,s using some mighty fine
>electronic parts, but unfortunetly they "dont walk the walk". So we are now
>building amps for 2,6,and 220 using 8877,s. Since I just joined the group I
>think thats great, but I would have started off with 8877,s or the like from
>the get go....Live and Learn! QRO is the way to GO. By the way, you probibly
>guessed by now I like Rush Limbaugh. 73 LOU
>
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