noise blanker nb

G8ZPX

Noise blanker is still so so performance

[Deleted User]

Yes it is. I wish they would take care of these BUGS. Seems more like they are more interested in bringing new stuff to market and less about the glitches.Other manufacturers will implement a fix and bring out an update in a week or two or three. It seems here you have to wait 6 months for a new version to arrive.Even then the bug might have not been gotten to.

G8ZPX

Noise blanker is still so so performance.

Over the weekend I had a very bad problem with a high level of ignition type qrm at s9+ on 80m (normally s5 noise level). I tried to track it down but it was so strong i failed to find it.

The noise blanker on the F6300 (v1.6 SmartSDR) did at best a mediocre job of taking out the noise, I still could not work a station at s9 due the ignition noise. I guess I must have gotten used to its poor performance, but do remember it was clearly better on my old F5k with PowerSDR. This was very disappointing, especially so considering that over a year ago FRS said th'd be releasing "a world class noise mitigation with v1.5".

Due to being unable to operate 80m during the weekend, I thought I'd try some other options and tests. I recently acquired a 32 year old Yaesu FT101zd mk3 from an SK. I powered it up and tuned 80m using same antenna etc. 

I then hit the NB button and seriously could not believe the ignition noise had completely vanished (s metre dropped by 3 s points), not a little bit lower but just gone! I was so surprised that I'd assumed the QRM source had stopped, but then turned NB off again and there it was very loud and clear as before.

Over the weekend with lots of playing around, I came to realize that the not-so-magic NB button can be much better on the Flex 6k. If it works so well with 32 year old analogue kit, surely there is much more improvement to come hopefully? 

Sorry FRS need to try harder on the NB, especially given the QRM rich environment we now find ourselves in.

73 de Steve G1XOW

Jim Gilliam

That is a very interesting observation. I have an Icom 7800 that uses DSP and I found, also, has a virtually worthless noise blanker compared to my old Kenwood 940. The 940's noise blanker runs circles around that of the 7800 and Flex 6500. Perhaps it is easier to implement noise blanking with hardware than software, or there is much work to be done of the algorithms.

Burch - K4QXX

I agree that the NB on the Flex-5000 is much better than on the 6000 series.  However, the addition of the WNB has helped a little on the noise at my location.  The regular NB seems to work better now since it was added back in the software after WNB was added.  If the regular NB would take out the noise on the Panadapter like the WNB does, that would be a huge improvement.

David

Are you using just the NB or have you tried the WNB, NR, ANF, and ACG in addition and combination of them? When you compared two radios were you also listening to a transmitting station or just comparing noise levels?

I agree the NB does not seem to be as effective since the WNB was added. The WNB is difficult to judge given the way it works a simple on/off doesn't always demonstrate how effective it is. The indicator does flash on and off showing it is doing something based of noise across the band. The ANF for me is a negative on the overall sound quality while might reduce noise it impacts the sound quality in an unpleasant way. The NR and ACG seem to be the most effective on reducing 'noise'. This is just my experience and I am sure a learning curving of how and when to use each. It would be nice to have a magic button that would make the noisier bands quieter and improve the intended signal quality.

Overall I find the Flex to be able to cut noise and retain voice quality great. It would be nice to have audio DSP similar to GAP Hear-It or BHI products in addition to all the RF DSP.

Bill -VA3WTB

The WNB works for me, my radio at night on 80M is not workable without it, I think they did a wonderful job on it.

Jim Gilliam

Even more interesting is that is seems to work wonderfully for some types of noise but not all types of noise.

pa0bie

I NEVER use the receivers in my 6700.  To much noise and no effective reducer and blanker. I have to recieve through the 6700 and "TEAMSPEAK" from a friend or use my 7800. Is there a Transmit-only 6000 coming out soon ?

Bill -VA3WTB

What companies bring out fixes each week? Flex has been bringing out big updates close to each 3 months.

Bill -VA3WTB

That is true and we all know that. WNB is only for wide band noise. And it is amazing on that noise. I hope soon they will tweak the NB in coming releases.

Jim Gilliam

Not being an expert on noise, what is the difference between wide band noise and non-wide band noise?

Bill -VA3WTB

It was explained in another post,, I don't know if I could find it.

Jim Gilliam

I am somewhat familiar with Fourier transforms and theoretically any function periodic or otherwise that is not purely sinusoidal contains an infinite number of frequencies of varying amplitudes and phases. So it would seem all noise would be wide band.  

Bill -VA3WTB

See if this helps.
4 months ago

 Tim - W4TME, Customer Experience Manager

• 4199 Posts
 
•  1299 Reply Likes

WNB works differently from NR so you really can't compare the two.  NR is a narrow bandwidth process that once converged, doesn't usually require re-convergence.  

With WNB, since the bandwidth it operates on is very wide, signals in other parts of the band away from your signal of interest may adversely affect the aggravate signal levels requiring frequent re-training.

In our alpha testing, we received feedback that there was no visual indication that WNB was temporarily disabled while it re-trained  after a significant change in signal level and the WNB indicator.  It seemed that WNB was "broken" (not blanking) when it was actually re-training.  If you want to propose a change, make it an idea post and allow public feedback on the merit of it.

Second, while WNB does operate at the SCU level, it can be applied on a per panadapter basis.  If WNB is not applied to a particular panadapter, we decided there was no need to display the blanking state of WNB.  And all slices within the same panadapter do show the same WNB enabled/disabled state.

David

Here is the description. In short "targeted at correlated impulse noise" looking at common noise across the band not just what you are tuned to.

https://community.flexradio.com/flexradio/topics/smartsdr-v1-5-0-is-now-available

Ken - NM9P

I seem to have missed the distinction between scu-based WNB and slice-based WNB. How does one select between the two?

Walt - KZ1F

Bill they are talking about NB not whole band noise filter.

David

I think it is per panadapter not slice. So if you have a slice on another panadapter you can open the DCP and toggle the WNB for that slice on that panadapter and the slice on another panadapter will remain unchanged. If you do that to slice in the same panadapter all the slice in that panadapter are changed.

Walt - KZ1F

I don't mean to be piling on but NB has never worked for me and wbn had only worked on two occasions. But when it worked it worked well.

Ken - NM9P

Oops, I mistyped.  I actually meant SCU-based vs. Panadapter-based... (I don't like typing on the ipad much for this reason.... by the time i manipulate the softkeys I forget what I was trying to say!)  

Correct...The slice-based Noise Blanker is the NB.  
But I had not heard anything about being able to activate WNB for either the whole SCU or only on a specific panadapter.  Have I missed something here?  

Ken - NM9P

David

You can turn it on/off globally/SCU using the left side list ANT and the WNB was added there.

Burt Fisher

What companies have a need to bring out fixes each week?

[Deleted User]

Not many but when there is an issue it is generally fixed fairly sooner than later. So I guess we have another 3 months to wait to see if the NB gets better. Bet you it won't as I have been waiting since 1.4 when I had a 6300.

Ken - NM9P

I wondered why it was added there, too.  I guess I need to read the appropriate manual page!   I noticed that when I turned it on and off that the indicator also toggled on the slice flag.  But I guess I didn't watch it when I toggled the one in the DSP pull down in the slice flag.  I have more playing to do tonight....

Gerald-K5SDR

NB works ONLY on the respective slice within a 24 kHz bandwidth.  WNB works at the SCU level only and applies to all slices that are enabled on that SCU as well as the panadapter itself.  NB has no affect on the panadapter since it works at the audio level.  WNB works at the RF sampling rate and thus can improve the panadapter on correlated noise.  Both may be used concurrently if needed.   NR is designed for uncorrelated noise.

KY6LA_Howard

Legacy NB vs DSP NB Before the invention of DSP, Noise BLANKING - which means removing impulse noise like ignition noise was accomplished by having a hardware circuit stop the receiver when it detected noise above a set threshold Hence Legacy NB receivers sound quieter because they are hearing nothing at all. This works pretty well for AM and SSB where your brain can integrate the cut off parts of the information but is much less effective for digital modes like CW and especially RTTY and all the modern digital modes where the loss of information can destroy the message. In the early 1980, DSP chips came into use in Ham Radio DSP attempts to do with mathematics what the older NB process used to do by removing impulse noise without losing the entire signal. DSP Based NB represented a significant improvement in Impulse noise mitigation because it did not remove all the information from the signal which meant that it worked much better with digital modes. NR vs NB A lot of hams on this forum are confused as to the difference between NB and Noise Reduction (NR). Noise Blanking means removing impulse noise only. NOISE REDUCTION Means removing pass band signal noise in addition to impulse noise DSP also gives you the ability to analyse receive pass band noise and using mathematics remove much of the noise while still retaining the information. NR is very effective in removing noise so you can hear weak signals that would normally be obscured by the noise WNB. Wideband Noise Blanking is a new feature of the Flex Radio 6000 series. It looks at the entire SCU receiver to find correlated noise signatures. When it identifies correlated noise it inverts the noise and sums it against the correlated noise to very effectively remove it without the massive information loss of NB. But it only works for correlated noise where it can identify a pattern or signature So while that old FT101 NB (I used to own one) worked really well on ignition noise and made everything quieter by several SUnits it really was not hearing that well because it had blanked out the weaker signals

Gerald-K5SDR

Unfortunately the desire for noise mitigation is like that of finding a single drug that will cure all forms of cancer.  Such a drug doesn't exist.  Just like there are many types and causes of cancer, there are a myriad of noise sources, types and signatures.  Some can be mitigated and some simply cannot.  Some sources we call noise are actually QRM that if mitigated would remove the desired signal as well.  This is much like the chemo therapy where the cure is worse than the disease.  That is why we allow you to turn the WNB setting so high that it starts to affect the desired signals.  Band conditions and the noise type/source can vary widely and so might the setting.

I have watched WNB drop the noise floor on 40m at our club station by 20 dB and make a dead band usable.  It works pure magic on that arching power line across the road from our office.  On the other hand, I have seen some types of noise at home that it will not reduce.  NB or NR may help depending on the type of noise.  None are a single bullet cure for all types "cancer."  

We will continue to do ongoing research into innovative noise mitigation techniques over time.  These are science projects.  I can guarantee that no innovation will remove all types of noise in a single algorithm until the scientists find a single cure for cancer.  

Walt - KZ1F

Nice explanation Howard...thanks. So, by extension then, is it fair to say, as more noise signatures are added WNB will work more consistently? Another related question, where the WNB works on the entire SCU, isn't that looking for noise signatures consistent across 14MHz? If a preselector is enabled (6500/6700) would the entire SCU look dead except for the selected pass band(s)? Or is the WNB in front of the preselector(s)?

KY6LA_Howard

Science will cure cancer before we get rid of all noise b

Walt - KZ1F

Didn't Michael Renni bring just such a cure with him in '52 but some idiot had to go and shoot him? Probably someone from big Pharma.