Background Noise Flex 6300 / TS-590

mlstutler

Today on Flex I have been seeing a lot of excess noise across the band scope.  It starts about 110 down building up to 100 and then drops off.  Looks very broad banded.  On a qso free frequency (20m) the noise is S5.  I then switch over to the TS-590 and on same frequency I get no noise at all on the S meter. Its quiet.  Could the rx in the Flex be that much better to pick up noise that the 590 can't even detect?

Mike, W8MLS

mlstutler

I found the source for the noise.   WNB was set on to 100% and behaves in a way I did not expect.  Turned off all noise processing and now see noise at about 120 db down on 20m.

Mike, W8MLS

Neal_K3NC

I was working with a friend on his interference problem last week and he also had turned the WNB to 100% and it was causing noise similar to what I find caused by solar panel regulators. We had just about decided on an intervention with the neighbor when I turned off WNB and the severity of the problem diminished greatly, enough that the neighbor will probably never know.

I do not know why it causes this but it was severe enough that I suggest people avoid that setting greatly (and maybe FLex should look at its effect).

73

Tim - W4TME

WNB, like any tool, it can be abused.  The radio was not engineered according to the "Spinal Tap" methodology where if it can go to 11, it must be better ;-)

Tim - W4TME

Could the rx in the Flex be that much better to pick up noise that the 590 can't even detect?

The 6300 does have better IMD DR3 (dynamic range), so it is very possible that  that the 6300 is hearing the noise better.

K3ZJ - Dave

Tim, what is your suggestion for how to use the WNB?

Trevor-EI2GLB

Not sure if this is revelent but when I fired up my 6500 for the first time after ARRL DX SSB I noticed that 15m the noise floor was up at 110db against the rest which were lower at there usual 125-130db, After a few tests I noticed that I was looking at 300khz of 15m I narrowed the bw down to 25khz and the noise floor dropped down to its normal, might be something to check, Thank Trevor EI2GLB

mlstutler

Tim the reason I had WNB set so high was frankly I don't see that it does much.  I always take any eq or dsp noise function to min / max to see what it will do.  Then I back off until it suits me.  

Tim - W4TME

WNB is not a "silver bullet" noise mitigation feature.  This is covered in the SmartSDR for Windows Software User's Guide.  If it is not working when the blanking is set at 95% of scale or greater, then you do not have well-correlated noise and WNB will not quash it.  In this case, using WNB when it is not effective on your noise source will degrade reception.

Tim - W4TME

Turn it on.  Move the blanking scale up to 80%.  if you do not see an improvement in the panadapter or hear it in the recovered audio, move the WNB slider up to 90-95%.  If still not blanking action, turn it off.  Your noise source is not well correlated and WNB will not be effective against it.  You can try the regular NB or NR.  And properly adjusting the AGC-T works wonders on band noise.