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interesting psk signal today...


Don - KM4UDX
 


So this PSKer was at (approx) 950, 1.8k and 2.9K on my waterfall.  Is this simply an overdriven TX?

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Don, km4udx, uBITX


Jerry N9AVY
 

Don:

You might try turning OFF AGC and inserting 18 db of attenuation .. your rig has that. On my FT-1000 this usually clears up problems with signals like that. However that station could be overdriving, have processor on, or simply running too much power (like 200 to 1 kilowatt). I encounter a few signals like this and now just tend to ignore them.

Jerry n9avy

On Sunday, July 26, 2020, 12:39:51 PM CDT, Don - KM4UDX <dontay155@...> wrote:



So this PSKer was at (approx) 950, 1.8k and 2.9K on my waterfall.  Is this simply an overdriven TX?

--
Don, km4udx, uBITX


Don - KM4UDX
 

Jerry -- good advice.  My little kit radio had no internal pads or notch filters. So I'll just move on to other open spots.  I'm always interested in Waveform spurs/harmonics due I part to my uBITX's colored history with same. But, once I learned how to control my own audio drive levels and monitor my output, and TX in the upper part of my bandpass, I seem to be out of the woods.
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Thanks!

Don, km4udx, uBITX


Jerry N9AVY
 

Less expensive radios don't have a lot of features of the more expensive ones. Have seen you on the air and your signal always looks good; so you must be doing something right.

When you run across a signal that is really wide, your only options are to wait him out until he's finished, move far enough away that it's no longer a problem or go to a different band.

Jerry n9avy

On Monday, July 27, 2020, 08:22:05 AM CDT, Don - KM4UDX <dontay155@...> wrote:


Jerry -- good advice.  My little kit radio had no internal pads or notch filters. So I'll just move on to other open spots.  I'm always interested in Waveform spurs/harmonics due I part to my uBITX's colored history with same. But, once I learned how to control my own audio drive levels and monitor my output, and TX in the upper part of my bandpass, I seem to be out of the woods.
--

Thanks!

Don, km4udx, uBITX


 

Don,

You could look at the S/N and IMD down at the lower left and tell by that but that doesn't look like a PSK signal.  Keep in mind the closer the IMD is to the negative value of S/N, the cleaner the signal.  So if it had a S/N 25 dB and an IMD -15 dB, the signal would be over driven.
From looking at the waterfall controls circled in red in my attachment you have to apply a lot of audio in to Fldigi to see the traces and you are probably not seeing workable signals.  Try changing that Zero to something around -20 and the 60 to about 40 and go from there.  Make sure the Diamond at the lower right is Green.  On the trace to the right, the psk signal is as wide as that red horizontal line.  The rest of it looks like noise.  The trace on the left looks like it has harmonics and to be over driven.  If you make changes to the waterfall controls you will have to drop the RX out of the radio to Fldigi.

John
KC3FL.


Don - KM4UDX
 

Thank you!  I have to get better at uBITX fldigi RX level management.  Thanks again!
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Don, km4udx, uBITX