[Elecraft] RE: PSK31 Power Level

[Don Wilhelm]

Parker,

Use the idle tone and look at the LED on the K2 - its response time should
be much shorter than your other meter.  Set the display to RF and you should
see the output level.

The TUNE from Digipan is a single tone.  You can use that for tuning a
manual tuner, but it is not as good for determining the power level.

Actually the very best way is to observe the power out on a 'scope.  Go to
CW and set for 5 watts (or any desired level), transmit and notice the
amplitude on the 'scope - then switch to PSK31 and adjust the audio input
until the PSK31 signal as the same amplitude as the CW signal was.  Note the
deflection on the K2 RF meter and you will know in the future where to set
the audio level.

All this is an effort to allow you to operate with the lowest IMD possible -
by setting up in that manner, you can be confident that you will not be
driving the K2 into compression at any point and your powr level should be
within normal ratings.

73,
Don W3FPR
  -----Original Message-----

  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




----------------------------------------------------------------------------
--



  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