WNB slider?

Steve G1XOW

Okay, what exactly is the WNB slider supposed to do or adjust?

I cannot see the miraculous noisefloor improvements from WNB that others have demonstrated. Maybe it's simply that I do not have correlated noise around my QTH?  I do have a low noise on most bands, typically -130dB on 17m -110 on 40m etc.

Apart from the odd SMPSU on 17/10m bands I have no major noise sources. On 80/160m I do see a lot of precipitation noise when rain is hitting the near-by national-grid power system (400KV system), but WNB makes no obvious differences to that kind of noise.

All I see is a kind of pumping effect which fills the waterfall with junk when the slider is above about 70%. Am I missing a trick here?

73 de Steve G1XOW

David

You are correct that it may have no or limited effect on the type of noise in your location. Thankfully I seem to be in a reasonably quiet location and have a similar experience. I do leave it on and usually no higher than 25-30. It is hard to determine if it is doing anything since it is correlation of noise seen across the spectrum at the moment is occurs and not a constant. This makes doing an on/off test less of obvious on the impact compared to the other filter options. Flex added the visual of toggling the WNB indicator for this reason so you can see when the filter is being applied. Overall each filter option has its own unique value and varying worth depending on the environment of each location and setup.

George KF2T

Hi Steve. Sounds like you're one of the lucky ones with a low (correlated) noise location. Here, at times WNB is truly miraculous; other times not useful at all. And yes, too much will lead to the "pumping" effect you have noticed. About the only "trick" with WNB is to adjust the slider slowly, giving the software time to do the maths on any eligible noise. Sounds like you're doing it right!

Bill -VA3WTB

Yes and make sure the AGC-T is set at the knee, or when sound begins to drop. As mentioned, the movement of the WNB slider needs to be moved slowly to allow the software to program. Some people move it a bit and leave it there a minute or so then move again and keep doing that till you find the best place. But if you don't find much happening then you have little (correlated) noise.

HCampbell WB4IVF

Pretty much the same here.  I too have the misfortune (?) of being in a rural and relatively low noise location, so I don’t get to use the NB on my radios very much.  The main recurring “correlated” noise here is from a neighbor’s electric fence.  The NB's on my Flex and Icom 7410 both do a good job there, but WNB has very little effect.  However, on one occasion something horrendous pretty much washed out an entire band on the panadaptor.  I turned on WNB, which cleaned it up very nicely, so I know it is effective under some conditions.    

EA4GLI

I still feel the question he presents has not been answered. What does the different slider value on the WNB mean? WBN works for me but I have no idea why and I feel like a shaman doing the noise reduction dance with no clue as to what I am doing.

Tim - W4TME

The WNB slider is a threshold adjustment that as you move it to a higher value (to the right) increases the blanking action (analyzing for correlated noise in the sampled signal and applying a level (gain) of blanking to remove it).  Move the threshold setting too far to the right and the algorithm will interpret uncorrelated band noise (real signals) as correlated noise which ends up corrupting the spectrum display.  Just like turning up the volume all the way can cause audio distortion.

If you do not have correlated noise in your signal, then there is nothing for WNB to operate on and it will have a minimal if any effect.

In general, you should only have WBN turned on when needed,  Leaving it on all the time when not needed can adversely affect SNR and puts additional computational overhead on the radio that is not needed.

EA4GLI

Thanks Tim!

EA4GLI

In order to add even more clarity to the WNB.

My limited understanding of it is that it "looks" for those noise signatures in a broad chunk of the spectrum and applies noise reduction to all of the SCU.

Does it work differently in the 6500/6700 vs the 6300? It seems that "better" processing power of those radios over the 6300 plus the 14 MHz per SCU vs 7 MHz might make WNB more effective.... right?

Walt - KZ1F

That poses a very good question Sal. It appears to me controls are , by and large, placed in the area that reflects their scope, whole radio scope in in the right hand pane, panadapter scope in the left-hand pane of each pan and slice scope on the slice flag. WNB control is in all three locations. It struck me there is some erroneous duplication of controls outside their area of scope which I attempted to correct t in XPSSDR. Is WNB a radio, pan, or slice scoped control, Tim?

Tim - W4TME

Sal - WNB works the same on across all 6000s.  And it operates at the panadapter level not the slice level.  The NB operates at the slice level (narrow band)

Walt - the duplication of WNB controls was a point of contention when designing the feature.  Since every NB in the world operates on the receiver audio, we felt that having it only in the panadapter controls would not lead to an intuitive user experience when they couldn't find WNB in the slice control panel.  Now if everyone read the manual before using the radio, this would not have been an issue :-)

Ken - NM9P

I actually like the WNB control being duplicated. There are times when it is easier or more logical to access it from one point than the other.

For example, If I have a pan open with no slice for visual observation of a wider spectrum, I can adjust the WNB to clean things up - using the control located on the LH pull-out, ANT menu.

But If I have a slice open and am making multiple adjustments to optimize reception of a particular signal, the DSP pull down from the slice flag is already open and the WNB control is very handy, even though its effect is not actually limited to THAT slice on the panadapter.  It reduces the number of mouse-clicks needed to do the job.  Which is always nice.

Ken - NM9P

EA4GLI

Read the manual?? You understand you are talking to hams right?? LOL

Bill -VA3WTB

There are manuals? 

Ken - NM9P

Isn't "Manual" when you adjust it by yourself instead of having it set on "automatic?"

Walt - KZ1F

@Tim, some of us are engineers. Engineers write manuals, the are notorious for not reading them. ;-)

Steve G1XOW

A friend of mine is a technical author as a career choice (yuk)   He's written very in depth stuff such as SQL design schema guides, DNA structural analysis, even a manual for NATO explaining how to operate radar-linked SAM missile launchers. He jokingly says that if "the product" is not obvious and intuitive enough without needing a 100 page manual then it should be sent back to the designers PDQ. What he meant was that he is only the author, and thus cannot make the product easier or more obvious to use, he can only help to explain obscure functions more clearly.