Missing squelch on USB


YaddUser@...
 

Using the latest SDR# with a HF+ Discovery.

I am unable to select squelch in USB mode.

Any suggestions?


jdow
 

Don't try to use squelch in SSB mode. Not supported.

{^_^}

On 20211125 13:02:00, YaddUser@... wrote:
Using the latest SDR# with a HF+ Discovery.

I am unable to select squelch in USB mode.

Any suggestions?


YaddUser@...
 

Thank you


KD7JYK DM09 <kd7jyk@...>
 

Any reason no squelch for SSB? Seems like a pretty major thing to leave out.

Kurt


jdow
 

So what do you currently use with SSB squelch?

{^_^}

On 20211126 10:11:12, KD7JYK DM09 wrote:
Any reason no squelch for SSB?  Seems like a pretty major thing to leave out.

Kurt






YaddUser@...
 

I installed sdr console and it has it so that’s what I’ll use. 


Ivan Boring
 

WebSDR Twente and SDR Console has it so your snide remark is uncalled for.

jdow <jdow@...> skrev: (26 november 2021 23:36:39 CET)

So what do you currently use with SSB squelch?

{^_^}

On 20211126 10:11:12, KD7JYK DM09 wrote:
Any reason no squelch for SSB?  Seems like a pretty major thing to leave out.

Kurt






--
Skickat från min Android-enhet med K-9 Mail. Ursäkta min fåordighet.


jdow
 

It is nice only if you have all large signals to deal with. It's not good for weak signals. There were some 75 meter rag chews that would have benefited from it if we didn't want to hear any moderately weak signals. If, however, it does what you want go for it. (And I REALLY wish Simon would build noise squelch into SDRC for FM.)

{^_^}

On 20211126 14:59:26, YaddUser@... wrote:
I installed sdr console and it has it so that’s what I’ll use. 


jdow
 

I know the SDRC version and how it works. It's not all that useful. I have another radio that has it. It shares the level of performance SDRC gives. With strong signals it's fine. If you are camping on a frequency waiting for possible weak signals, it not good. Minute changes in noise levels can trigger on signals you cannot hear or can block triggering on weak signals you can hear. That is a "feature" around here. I was wondering if you had something I didn't know already. Is WebSDR performance different from SDRC?

I'm not sure it's something I'd try to talk Youssef into when he has other work to do.

{^_^}


On 20211126 15:23:40, Ivan Boring wrote:
WebSDR Twente and SDR Console has it so your snide remark is uncalled for.

jdow <jdow@...> skrev: (26 november 2021 23:36:39 CET)
So what do you currently use with SSB squelch?

{^_^}

On 20211126 10:11:12, KD7JYK DM09 wrote:
Any reason no squelch for SSB?  Seems like a pretty major thing to leave out.

Kurt






--
Skickat från min Android-enhet med K-9 Mail. Ursäkta min fåordighet.


KD7JYK DM09 <kd7jyk@...>
 

"So what do you currently use with SSB squelch?"

Off the top of my head, personally, every SSB transceiver I've owned, used, heard about, or seen daily since the 70's. Beyond that, just about everything I've seen, or heard about going back a few more decades. It all kind of runs together when one goes back about 3/4 of a century.

Is there something unique to SDRs where constant uncontrollable background noise is desirable when no signal is present, or have I missed something where the default is now, all noise, all the time?

"It is nice only if you have all large signals to deal with. It's not good for weak signals."

Weak is relative, and constant background noise can get annoying, especially when uncontrollable for hours, days, weeks, months, years...

Other times, I like to turn it on.

Then, of course, there's anything un-weak, one may wish to monitor, where squelch would be kinda critical, like on/off, volume, tune, other crazy controls like that.

But, let's look at some basic reception. You may want your squelch off, because a band is barely in, and you're trying to hear a 100W station 8,000 miles away on a regular basis, for hours on end. I may want it on, because I'm listening for a 25W station 3 miles out that transmits twice a week for a few minutes, or, anything stronger, or closer, than what you are listening for. I think on/off (at some level) is more practical for the masses than, "No you can't have that, at all, ever, because someone, somewhere, may not wanna use it once, for a signal they tried to hear"

Kurt


Joe M.
 

Personally, I just use noise reduction, but that's me.

Joe M.

On 11/26/2021 11:59 PM, KD7JYK DM09 wrote:

Is there something unique to SDRs where constant uncontrollable
background noise is desirable when no signal is present, or have I
missed something where the default is now, all noise, all the time?


KD7JYK DM09 <kd7jyk@...>
 

On 11/26/2021 21:03, Joe M. wrote:
Personally, I just use noise reduction, but that's me.
I use that at times, as well. SSB- AGC, NB, DSP, et cetera, in various combinations, and settings, works fine for some comms, obscures others. None of that is squelch though, and there's still background noise without that, although diminished, and less obvious with other noises obscuring it, until those are gone. It may not seem like much in the short-term, but think of it all the time. What's that hiss? Do I have neurological problems? Is that a gas leak? Is the building flooding? Is the vehicle over-heating? Do I have a tumor? There's something to be said for no noise at all, signal only, and noise always, with some signal, sometimes. Weak signal? Crank up the hiss, make it worse, to hear the little signal within it. It starts annoying, gets worse, at best, for those that don't like it. Occasional use is one thing, but over time, the background noise becomes dominant. Not just me, several others around equipment over the years have commented about the constant hiss, one even grabbing equipment, and having a party with it, simply because of the draw of the constant hiss. Bad, bad, bad.

Kurt


Simon Brown
 

FWIW,

 

SDR Console uses Voice Activity Detection from the rrnoise project, I find it to be very good with strong-ish signals, but weak signals are difficult. The best algorithms are sadly patented so can’t be implemented.

 

In 2021 I’ll be working on noise-based squelch, if only someone would write this for me 😊 .

 

FWIW there are various AI projects written by the pros, they don’t produce significantly better results in a noisy environment.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: airspy@groups.io <airspy@groups.io> On Behalf Of jdow
Sent: 27 November 2021 01:32
To: airspy@groups.io
Subject: Re: [airspy] Missing squelch on USB

 

I know the SDRC version and how it works. It's not all that useful. I have another radio that has it. It shares the level of performance SDRC gives. With strong signals it's fine. If you are camping on a frequency waiting for possible weak signals, it not good. Minute changes in noise levels can trigger on signals you cannot hear or can block triggering on weak signals you can hear. That is a "feature" around here. I was wondering if you had something I didn't know already. Is WebSDR performance different from SDRC?

I'm not sure it's something I'd try to talk Youssef into when he has other work to do.

{^_^}

On 20211126 15:23:40, Ivan Boring wrote:

WebSDR Twente and SDR Console has it so your snide remark is uncalled for.

jdow <jdow@...> skrev: (26 november 2021 23:36:39 CET)

So what do you currently use with SSB squelch?

{^_^}

On 20211126 10:11:12, KD7JYK DM09 wrote:

Any reason no squelch for SSB?  Seems like a pretty major thing to leave out.

Kurt



 


--
Skickat från min Android-enhet med K-9 Mail. Ursäkta min fåordighet.

 


Simon Brown
 

Ah – I mean 2022, I see we’re already into 2021.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: airspy@groups.io <airspy@groups.io> On Behalf Of Simon Brown
Sent: 27 November 2021 08:10
To: airspy@groups.io
Subject: Re: [airspy] Missing squelch on USB

 

FWIW,

 

SDR Console uses Voice Activity Detection from the rrnoise project, I find it to be very good with strong-ish signals, but weak signals are difficult. The best algorithms are sadly patented so can’t be implemented.

 

In 2021 I’ll be working on noise-based squelch, if only someone would write this for me 😊 .

 

FWIW there are various AI projects written by the pros, they don’t produce significantly better results in a noisy environment.

 

Simon Brown, G4ELI

https://www.sdr-radio.com


KD7JYK DM09 <kd7jyk@...>
 

SDR Console uses Voice Activity Detection from the rrnoise project, I find it to be very good with strong-ish signals, but weak signals are difficult. In 2021 I’ll be working on noise-based squelch, if only someone would write this for me 😊.
No problem, and thanks. 2021? For "weak" signals, I leave the squelch off, as some signals can't even be heard, but seen, and for the signals that are WAY down in the noise, just energy at some level, no squelch, no "signal" processing of any type, generally just a bandpass filter, RF as best as can be detected, then processed externally into something containing intelligence.

For stronger signals, local, regional, anything above a certain threshold, suggesting closer/stronger, I use squelch, much as one would in AM, or FM. The mode certainly doesn't matter, AM, FM, SSB, CW, et cetera, just the lack of noise when there is no signal.

Sometimes I'm delving into the abyss of energy in space, other times, listening to something needing no more complexity than one would expect from a 60 year old CB radio, on/off/volume, tune, squelch.

Kurt


jdow
 

I can dredge out some code if needed. You need unfiltered demodulator output so you can feed it to both a high pass filter usually around 4 kHz and a 3 kHz or so low pass filter. You detect noise energy via the 4 kHz filtered demodulator output. This drops very rapidly as the demodulator signal to noise ratio reaches threshold and some what slower as  you go above threshold. Fairly simple filters work. The filters I used were loosely derived from CuteSDR and are -1dB at about 3 kHz and -50 dB at 3.9 kHz for LPF and -1dB at 3.9 kHz and -50dB at 3 kHz for HPF. Take the HPF output, square and average it. Look for a drop in that noise amplitude as carrier comes up. Use it to switch the audio out of the LPF.

Simpler filters may also work. I suspect bi-quad HPF and LPF will do. There is REALLY nothing exotic about it. It's been used on analog radios for - eek - half a century to my knowledge. (Gawd I feel old now.) The time I used it the high frequencies were data so I had to use a 50 Hz LPF for the noise filter. (Sonobuoy receiver for US Navy S3A ASW aircraft.) It is simple and seriously magic in its operation.

{^_^}

On 20211127 00:17:29, Simon Brown wrote:

Ah – I mean 2022, I see we’re already into 2021.

 

Simon Brown, G4ELI

https://www.sdr-radio.com

 

From: airspy@groups.io <airspy@groups.io> On Behalf Of Simon Brown
Sent: 27 November 2021 08:10
To: airspy@groups.io
Subject: Re: [airspy] Missing squelch on USB

 

FWIW,

 

SDR Console uses Voice Activity Detection from the rrnoise project, I find it to be very good with strong-ish signals, but weak signals are difficult. The best algorithms are sadly patented so can’t be implemented.

 

In 2021 I’ll be working on noise-based squelch, if only someone would write this for me 😊 .

 

FWIW there are various AI projects written by the pros, they don’t produce significantly better results in a noisy environment.

 

Simon Brown, G4ELI

https://www.sdr-radio.com



jdow
 

I wonder if there is a place within the RNNOISE algorithm you can pull off a squelch level. I'm not sure it would be as magic seeming as the FM noise squelch; but, I also bet it would be an improvement over pure signal level squelch.

{^_^}

On 20211127 00:38:35, KD7JYK DM09 wrote:
SDR Console uses Voice Activity Detection from the rrnoise project, I find it to be very good with strong-ish signals, but weak signals are difficult. In 2021 I’ll be working on noise-based squelch, if only someone would write this for me 😊.

No problem, and thanks.  2021?  For "weak" signals, I leave the squelch off, as some signals can't even be heard, but seen, and for the signals that are WAY down in the noise, just energy at some level, no squelch, no "signal" processing of any type, generally just a bandpass filter, RF as best as can be detected, then processed externally into something containing intelligence.

For stronger signals, local, regional, anything above a certain threshold, suggesting closer/stronger, I use squelch, much as one would in AM, or FM.  The mode certainly doesn't matter, AM, FM, SSB, CW, et cetera, just the lack of noise when there is no signal.

Sometimes I'm delving into the abyss of energy in space, other times, listening to something needing no more complexity than one would expect from a 60 year old CB radio, on/off/volume, tune, squelch.

Kurt






paul
 

Simon's SSB squelch is great!
I use it a lot on monitoring MWARA channels (@jdow)

The squelch in SDR-Radio is the closest thing to syllabic squelch found in dedicated Marine/Air equipment.
In the past I used Sailor/Debeg and Icom marine receivers with syllabic.

You need a squelch that has a good balance between voice-only detection, hysteresis timing, immunity to non-voice (carrier) signals, immunity to QRN static. Simon's squelch suppresses everything until a weak voice pops up.

The only "downside". A contradiction in itself:
It also suppresses Air Selcal most of the time, as it is no voice :-)

73
Paul
PD0SWL



YaddUser@...
 

I agree Paul. That’s how I use it.