Noise Blanker and Noise Reduction

  • 2
  • Question
  • Updated 4 years ago
This is part praise and part question....

I tried the NR this evening from the new update. What a difference so far. Take a bunch of hiss out but it also seems to attenuate the highs in the signal leaving the resulting audio just a little muffled. But still a big improvement from last version.

How exactly is the NB supposed to work. I know for now it is just in the slice (unfortunately....neighbor's fence is making the display useless), when turn the NB on it does cut the popping sound BUT the panadapter display "inside" the slice is still seems like the NB has no effect on the display at all, inside or outside the slice, only the audio.


Photo of Greg


  • 656 Posts
  • 63 Reply Likes

Posted 4 years ago

  • 2
Photo of Thom Baxter

Thom Baxter

  • 26 Posts
  • 3 Reply Likes
I have the same question on the use of the ANF? It seems to make little difference in reduce or changing the sound characteristics.


Photo of Eric - KE5DTO

Eric - KE5DTO, Official Rep

  • 637 Posts
  • 194 Reply Likes
Our engineers have put some real effort into these DSP functions leading up to v1.0. I would recommend that you reserve judgement until then. I believe there will be writeups for each of these controls in the manual which is set to be released with v1.0. Thanks for your patience.
Photo of K4EAR


  • 138 Posts
  • 17 Reply Likes
"Praise the Lord and pass the ammunition!"
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3777 Posts
  • 1151 Reply Likes
I finally (unfortunately) had opportunity to test the NB yesterday afternoon as my powerline noise returned for a while. It was intermittent with short breaks between long spans of buzz.

The NB was very effective, making s4 signals buried under s7-s8 noise perfectly readable. But as others noticed, watching the pan display for the breaks in the noise so I could see where to tune was a very interesting activity, to say the least.
It was like hunting for treasure on the bottom of a murky sea with occasional glimpses of light-enhanced gold coins on the bottom!

I have read the previous discussion posts about activating the blanker on the pan to be able to see what we are tuning. I will welcome this addition when it arrive.

On the plus side.... The Blanker was very effective and did not seem to be much affected by other signals on the band. It seemed to be as effective or more than that on my 1500 and made some completely uncopyable 10 meter signals completely jump out of the noise. This was very nice.

Keep up the good work. I can't wait to try out the NB on V 1.0... But I hope I don't need it very often!

ANF worked very well, on the sideband it works for. I know that this small bug (another embarrassingly simple math or logic error?) will be fixed in the next release.

I tested it on a S9+20 RTTY signal just outside the 80 meter band and it silenced BOTH the mark and space signals equally at the same time.

I could blank out S9+20 CW signals and only hear the thumping. Steady carriers just vanished. And if I didn't turn the control up too much, it didn't color the audio nearly as much as the ANF on my 1500 did. This is going to be nice.

I will reserve further comment on the NR circuit until V 1.0.
Photo of Michael - N5TGL

Michael - N5TGL

  • 307 Posts
  • 101 Reply Likes
I was using the NB and ANF yesterday and was rather dismayed by the performance. (0.16.4)

The NB didn't seem to work all the time, sometimes it took 3 on/off cycles to get it to engage, and then it worked fine...but after about 5 seconds or so, you could start hearing noise creeping back in. I don't quite understand that.

I've had pretty much zero luck with ANF, every now and again it works, but I heard quite a bit of carriers and no supression. The 5000 had an amazing NB and ANF, this seems to fall pretty far short of that performance. Of course, it worked on the entire band, not just the slice, which should be an awesome improvement if it gets working right.

I'll hold off on further judgement until 1.0, which should be Real Soon Now, but wanted to make my observation known.
Photo of W5XZ - dan

W5XZ - dan

  • 562 Posts
  • 82 Reply Likes
michael, I was fiddling with NB again this am; have had s-7 line noise to west on 160 lately; I found that you have to 'jiggle' the setting button a little to make it come on; here, have to run it clear up to 90 or so to get any action. but, sure enough, there was vk3io cq'n on 1822, 559...

all FWIW; Our last day with 0.16.4 ?? 73
Photo of Michael - N5TGL

Michael - N5TGL

  • 307 Posts
  • 101 Reply Likes
Yep, that's exactly the same behavior I'm experiencing, right down to cranking up the slider to 90. I was hoping 1.0 might be out, but with me hitting the snore shelf in an hour, looks like I won't see it tonight.
Photo of K4EAR


  • 138 Posts
  • 17 Reply Likes
I still filter my audio out on the 6700 thru a DSP-599zx inline with the the near field powered monitors. I'll pass judgment after 1.0. Even with the 5000 and latest revision of PSDR, the ANF, NR did not seem to work for low level signals at S-5 and below. We'll see...