[AMRadio] Power Levels

[B. Morgan Sherrod]

Dave,

I suggest you give it a REST !  This discussion has gone beyond answers, and
I think you have been given plenty of them.

w5ami

----- Original Message -----
From: <Wt8r at aol.com>
To: <w5omr at w5omr.shacknet.nu>; <amradio at mailman.qth.net>
Sent: Sunday, June 30, 2002 6:38 PM
Subject: [AMRadio] Power Levels


> Here you go Jeff, as requested:
>
> Answered on the list.
>
> Jeff wrote:
> <Would you answer a question for me, please?>
> <Why did you create your reply to me, off-list, and in a Word document
file?>
>
> I did it (Word document/off list) because there are too many points to
cover
> in a logical and succinct manner.
>
> --------------------------------------------------------------------------
----
>
> -------------------------------------
> (W5OMR) <snip>
> Much the same way that a 100w rice-box needs to be lowered to somewhere
> around
> 25 watts of carrier, to allow for full audio output.
> --------------------------------------------------------------------------
----
>
> --------------------------------------
> (WT8R)
> This again is in error....perhaps an old wives tale or cod swallop.  The
> reason that the rice boxes need to be lowered to 25 watts is that the
final
> transistors are not
> specified (selected) for continuous AM operation because, in the SSB mode,
> the
> duty cycle is quite low whereas in AM it is 100%.
> --------------------------------------------------------------------------
----
>
> ---------------------------------------
> (W5OMR)
> No sir. The transistorized finals in your Yaewoodcom will allow you to
output
> 100w.
> --------------------------------------------------------------------------
----
>
> --------------------------------------
> (WT8R)  This is wrong…..you cannot run 100W AM out of  modern (100W
nominal)
> transceiver nor can you run 100W RTTY.
> --------------------------------------------------------------------------
----
>
> ---------------------------------------
> (W5OMR)
> There are three components of an AM signal; Carrier, Upper Sideband and
Lower
> Sideband.
> AT THE MOST, you can run 33.3 watts of carrier, because you'll need 33.3
> watts
> of Upper Sideband energy
> as well as 33.3 watts of Lower sideband energy to complete the AM signal.
> --------------------------------------------------------------------------
----
>
> ---------------------------------------
> (WT8R) Quoting from the W6SAI Handbook Vol.  22, page 15.3:
> "While the average RF voltage of the modulated wave over a modulation
cycle
> is the same as for the unmodulated carrier, the average  power increases
with
> modulation.  If the radio frequency power is integrated over the audio
cycle,
> it will be found with 100 percent sine wave  modulation  the average RF
power
> has increased 50 %.   This additional power is represented by the
sidebands,
> because as previously mentioned, the carrier power does not vary under
> modulation.  Thus when a 100 watt carrier is 100% modulated by a sine
wave,
> the RF power is 150 Watts-100 watts in the carrier and 25 watts in each of
> the two sidebands."
> --------------------------------------------------------------------------
----
>
> --------------------------------------
> (W5OMR)
> 25w of carrier, and 25w of sideband power in each sideband - upper and
lower,
> with a little for overhead.
> --------------------------------------------------------------------------
----
>
> --------------------------------------
> (WT8R
> I believe this to be in error. There is only 12.5  watts TOTAL of audio in
> both sidebands if the carrier is only 25W.
> --------------------------------------------------------------------------
----
>
> ---------------------------------------
>  (WT8R)
> I ask again, if you tune your amp up for 1500W output PEP, and then,
without
> changing anything, switch to CW and key it, what does the wattmeter read?
>
>  73 de
>  Dave in Dayton, WT8R
>
>
>
> --- StripMime Report -- processed MIME parts ---
> multipart/alternative
>   text/plain (text body -- kept)
>   text/html
> The reason this message is shown is because the post was in HTML
> or had an attachment. Attachments are not allowed.
> Please post in Plain-Text only.---
> _______________________________________________
> AMRadio mailing list
> AMRadio at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/amradio
>