JT65 JT9 TX Panadapter Waveform gets distorted overtime.

  • 2
  • Problem
  • Updated 5 years ago

Anyone see this problem? 
After 3-4 hours of 6500 operation (Digital JT Mode10w output) the TX Panadapter Waveform starts to distort.  A little at first then increasing in severity until even the output power starts to fluctuate
(30-40% downward as observed on an external wattmeter). This distortion seems to happen approx. 7 times in a 10 sec. period (see pic # 3 waterfall below).  This problem has been occurring since I received my 6500 (May-2014 SmartSDR 1.2.17). I was using a laptop during this period and suspected the laptop as the source.  Recently I replaced a dead desktop computer with a new Dell XPS Desktop
system (i7-4790). The distortion occurs with this system also.  Both computers used a direct connection to the 6500. The two PC systems run Windows 7 Home Premium with 8 GB mem.  This occurs while using DAX as an input.  I would like to try the ACC input, but do not have the connectors. This would help prove either Software or Hardware problem.

Tried the following one at a time

               ATU Retune,   Restart WSJT-x,   Restart DAX,

              Restart SmartSDR,   Shutdown and Reboot PC

The only thing that temporarily corrects this problem is
a complete system shut down (Power off All) PC, 6500 and PSU.  After restarting all, the 6500 works great
for another 3-4 hours then the distortions starts to reappear. This problem has
occurred with SmartSDR ver.1.2.17, ver. 1.3.0, and ver. 1.3.8.  Resetting the 6500 to factory defaults has not fixed this problem, it reoccurs.  I have deleted all of my profiles and created all new ones after the ver. 1.3.8 upgrade.  When this distortion occurs I have pressed the Transmit Panel Tune Button (10w tune power). The Panadapter TX waveform remains clean.

This problem is very repeatable on my 6500.

 Pic-1 show a little distortion (lower portion of waveform) on a Pure Tone being sent from WSJT-x JT9 mode (tune button), occurs on JT65 setting also.

Pic-2 shows distortion when power output is affected (as observed on external wattmeter). Panadapter TX waveform shows distortion the width of the receive filter.

Pic-3 shows distortion on the waterfall display (approx. 7 times in 10 sec. period).

Any Ideas?

Did I miss something?

If this distortion is actually being transmitted is it increasing the BW of my signal?

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Dick / KC9YRA

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Posted 5 years ago

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Bob Wright, N7ZO

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