Title: Neue noise reduction & autonotch
Post by: DD4WH on 03. February 2018, 13:43:47
Liebe UHSDR-Freunde,
eine erste firmware-Version ist da, welche die neue noise reduction und einen funktionierenden autonotch anbietet.
Die neue sogenannte spectral noise reduction ist eine doch recht aufwändige Teamarbeit gewesen und hat den -zugegebenermaßen sehr hohen- Anspruch, vielleicht sogar eines der standalone-DSP-noise reduction-Geräte á la Lingua Sprachextaktor und bhi NR zu ersetzen (oder zumindest in die Nähe der sehr hohen Qualität dieser Geräte zu kommen) . . . mal schauen, ob das so ist, wir sind auf Eure Kommentare/Meinungen gespannt.
Bitte ausgiebig testen!
Technisch gesehen ist die höchste Qualität der noise reduction bei Filterbandbreiten <= 2k7 zu erwarten, bei Filterbandbreiten >= 5kHz schaltet sich die noise reduction automatisch ab.
Normale Anwender brauchen nun nur noch eine einzige Einstellung für die noise reduction (NR strength --> mit encoder in der DSP box) vorzunehmen, der auto notch benötigt gar keine Justierung, einfach über die DSP box einschalten. Es könnte sein, dass der autonotch mindestens so gut läuft wie vorher. Auch ein simultaner Betrieb der NR plus auto notch sollte jetzt laufen.
Für experimentierfreudige Anwender stehen im DEBUG menü eine kleine Auswahl an Einstellungen zum Spielen bereit, für den autonotch drei Parameter im CONFIGURATION menü.
Viel Spaß damit!
73 Frank
P.S.: die Aktualisierung des Wikis mit einem update der implementierten Algorithmen und Technologien für die NR mache ich im Laufe der nächsten Wochen fertig, wir haben so oft geändert und feingetunt, dass einige der Angaben im Wiki veraltet sind.
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Title: Re:Neue noise reduction & autonotch
Post by: DD4WH on 03. February 2018, 13:59:50
Dear UHSDR-friends,
the first firmware version with spectral noise reduction AND functional auto notch filter has been released.
The implementation of this so called spectral noise reduction was a rather laborious task and had the rather sophisticated claim of substituting one of those standalone DSP noise reduction boxes (bhi etc.) or rather to get some where near the noise reduction power of those solutions. We would be delighted to hear about your opinions on that!
Please test extensively!
From a technical point of view, you can expect the highest quality of the noise reduction with filter bandwidths <= 2k7.
With filter bandwidths >= 5kHz the noise reduction shuts down automatically (without you noticing, except that the noise comes back again ;-)).
Standard users only have to adjust the strength of the noise reduction with the encoder when the DSP box is active, for the auto notch you do not need to adjust anything, just switch it on using the DSP box. Simultaneous action of the NR and the autonotch also works now.
For experimental use, please find some selected adjustment possibilities for the spectral NR in the DEBUG menu, for the autonotch filter in the CONFIGURATION menu.
Have fun!
73 Frank
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Title: Re:Neue noise reduction & autonotch
Post by: peter_77 on 03. February 2018, 16:12:24
First test on a standard mcHF hardware works pretty good with NR level of 2. Finally all crackling noises which made this function unusable in relases before (on mcHF hardware) are fully gone now.
Its a very impressive reduction of noise !
The audio has the best results as you mentioned with 2,7k bandwith. I actually listen on 80m a local QSO with a 2m wire here inside the room where without NR i can barely read one station. With NR active i can read also the partner which usually vanishes in the noise. With NR its an impressive difference.
With the I40 UI as usual no issues seen.
What would be really helpfull would be a list of the NR standard values in the setup which should be set as basic standard values.
Actual settings here: NR beta = 960, NR asnr 30 and NR smooth wd. = 4
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Title: Re:Neue noise reduction & autonotch
Post by: DD4WH on 03. February 2018, 17:29:40
Hi Peter
thanks for the report!
We have been testing the new NR for hours, days (weeks? ;-). And we tried to find the best parameter settings.
So in this release ALL the parameters are already set to those values we found most helpful as defaults at startup.
So just leave them as they are, or report here if you found more optimal setings!
Have fun, 73 Frank |
Title: Re:Neue noise reduction & autonotch
Post by: SP9BSL on 03. February 2018, 20:16:15
Hi,
I can confirm too. Played all the day with 20m, 40m and 80m at evening. It just works! No clicking or similar efects. Now it stays switched on all the time.
mcHF with 480x320 lcd 192kB of RAM/1MB Flash.
Good job! Thank you!
Edit: no need to change anything in Debug menu for me. |
Title: Re:Neue noise reduction & autonotch
Post by: DF8OE on 04. February 2018, 08:58:49
Some observation to the values in debug menu:
They are preloaded during boot with (very good working) values. If you play with them and try to load defaults via DFLT button there are defaults loaded - but these differ from the initialization values at startup. It would be great if these values would be unified...
At my OVI40 NR now is "on" all the time, too. Autonotch is running as before - I do not miss anything here.
At OVI40 there is a clicking every few minutes - but it is not bothering and not reproduceable. Sometimes it works 30 minutes quite normal and then there is one 0.5s "scratch" sound.
vy 73
Andreas |
Title: Re:Neue noise reduction & autonotch
Post by: DD4WH on 04. February 2018, 11:15:26
Thanks Andreas for the feedback!
Default values have been corrected now. PR is out.
Strange, that sound. I have it sometimes when changing bands or demod mode, when signal levels are very different. Seems the audio causes distortion before the AGC can react . . . which is quite strange because I thought that we have a look-ahead-AGC!?
We need more observations on that, when this occurs and description of the situations when this occurs . . .
73 Frank |
Title: Re:Neue noise reduction & autonotch
Post by: peter_77 on 04. February 2018, 11:36:25
I can only hear it if i have no antenna connected, so no external noise floor. Then you hear a slightly sound as like you are sitting in a tin barrel or bath tub with a waterfall beneath or so. This increases when you narrow the bandwith.
But.... this is more or less not hearable and its totally gone when an antenna is connected.
I could not reproduce the clicking sounds on classical mcHF UI as heard in releases before.
And another positve thing is that the hissing and scratchy sound during setup menue operation in classic mcHF UI is fully gone now as well.
Great job.
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Title: Re:Neue noise reduction & autonotch
Post by: DD4WH on 04. February 2018, 12:13:06
Let us make it clear that we are talking about the same thing.
I am not talking about some faint ticking/clicking, but a really loud crash sound, like an explosion/distortion, which is very rare.
My impression is, it only occurs during the first minutes after flashing a new firmware! After that, when rebooting, it does not occur any more . . . :-)
The bath tube sound is the remaining artefact coming from the NR. And yes, I can confirm, it completely vanishes with moderately strong or strong signals, but is existent in small or no signal/noise ;-).
73 Frank |
Title: Re:Neue noise reduction & autonotch
Post by: DF8OE on 04. February 2018, 12:28:11
Hi Frank,
I can agree but for me "crashing sound" does not vanish completely. But it is very, very rare and I do not see any chance to fix it (excluded by chance).
The advantage is that you cannot fall asleep and die because of hunger. You will be wakened up by this sound after a few hours....
Very low priority. All is working fine.
vy 73
Andreas |
Title: Re:Neue noise reduction & autonotch
Post by: dg9bfc_sigi on 07. February 2018, 10:53:51
seems as the new nr now works near perfect ... will test it in the next days with real dx signnals that are just in the noise
(80m usa/europe at night)
dg9bfc sigi
ps autonotch works superb ... also together with nr |
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