The power level control only sets the threshold for the ALC and has no
effect on the linearity of the final. Running the control at 100 but
adjusting the audio input for about 25 Watts output will ensure the least
amount of unwanted level-changing during a PSK-31 transmission. That being
said, I have determined that the software ALC apparently operates
unpredictably to some degree at any audio level input. You can demonstrate
this by running a tone into AUX input and reducing it to where the ALC light
goes out, then start reducing it more. At various points, the output will
appear to 'hunt' while the input is kept steady. This relates back to an
earlier thread about 'talk power' which is dependent on ALC action which
appears to be quite aggressive in the V 2.x firmware.
BTW...has anyone determined the function or the proper setting of R-19 in
the A5 ALC circuit?
Ron N6IE
www.N6IE.com
(Formerly N6AHA)
----- Original Message -----
From: <K4IA@aol.com>
To: <tentec@contesting.com>
Sent: Friday, December 29, 2006 5:52 AM
Subject: Re: [TenTec] TenTec] TX EQ = -14 dB for PSK31
Interesting that you leave the transmit power at 100w and control the
output
by reducing the audio drive. Wouldn't that underdrive the output and
introduce non-linearities? I have always reduced the Orion power output to
25w and
then adjusted the audio drive to just below the ALC lighting up. I don't
remember having to change settings from band to band.
What say list? Which is the better way to control the PSK output?
k4ia
Craig "Buck"
Fredericksburg, Virginia USA
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