[Elecraft] RE: PSK31 Power Level

[Parker Buckley]

Don,

 

It's that "idle tone" that I question.  If I push the Tune button (Digipan)
I get a single tone.  If I push the T/R button, I get a dual warbling tone
which gives about half the reading on the wattmeter (probably something like
an average of the two warbling tones and some off period between them).  So
you're saying to bring up the single tone to only five watts?   That puts
the warbling tone down to the 2-3 watt level.  I guess the peaks are
probably hitting the five watt level, but the meter can't keep up.

 

Thanks,
Parker

 

  _____  

From: Don Wilhelm [mailto:w3fpr at earthlink.net] 
Sent: Sunday, February 25, 2007 6:23 PM
To: Parker Buckley; W3FPR - Don Wilhelm; Elecraft at mailman.qth.net
Subject: RE: PSK31 Power Level

 

Parker,

 

The best for running PSK31 is to set the power knob to 10 watts or above.

Then adjust the level from your computer soundcard so your power meter goes
up to 5 watts with the idle tone.  There should be no ALC bars showing.

 

Also, be certain that you have the compression set to 1:1.  If you are using
the RTTY mode, there is a separate SSBCr setting in the menu, and that is
independent of whatever compression level you may be using for SSB.  If you
are using the RTTY filters, remember that there is yet another set of 4
filters that need to be properly set up for width (use the OP1 filter for
FL1 - that is important), and set the remaining filters whereever you would
like in terms of width and filter center.  Use Spectrogram and it is easy.

 

If you want to increase the gain for the KDSP2 again for whatever reason,
you may have to add a divider at the two inputs of the Fixed Audio board -
something like 2.2k in series and then 2.2k to ground should give you good
results.

 

73,

Don W3FPR

-----Original Message-----

Elecrafters,

 

Don has been coaching me off-list through installation of one of his fixed
audio output kits, which I've had around here for many months, un-built.
All went well, except the audio through my computer was distorted.  I
eventually tracked it down to the K2 DSP gains being set too high.  I was
getting away with that in the basic K2, but the fixed audio unit doesn't
like being pushed that hard.  I've now carefully reset the DSP gains to get
the same audio level with DSP and with DSP bypassed.  Everything is working
great.  I'm now reminded of a nagging question since the last time I strayed
from CW to PSK 31.  I've read numerous places about setting the power level
(mine is a QRP K2) to five watts for continuous use like PSK.  Does that
mean five watts for single tone like CW, or five watts average as the two
tones warble back and forth?  I'm using a WM-2 wattmeter in the output.
Running about 10 watts single tone, I get about five watts warbling and a
single ALC bar flickering.  Is this okay, or should I back it down to five
watts single tone?  I thought this question might be of interest to a wider
audience.

Parker

WD8JOL  K2 #2636

 

...back to work tomorrow, and peace for Don.