-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 03 July 2021 09:02
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] SNR meter, bandwidth and gain adjustment for transverters

Hello Simon.

I asked about the main dB scale in the receiver window and how it relates to bandwidth, you did not reply. I see that the question has been asked before, What exactly does it display? Also, the SNR reading does not change with filter BW, surely it should. How does the SNR meter work? For instance, it shows a positive SNR where there is no signal present in the filter passband so perhaps it is finding the max a signal in a wide passband? It would be better if it only looked inside the filter BW.

Finally, as a feature request would it be possible to have some manual gain adjustment to compensate for transverters and LNAs?

Many thanks

Conrad PA5Y

I have answered this before, also I cannot answer all questions as soon as they are asked, I do have my own priorities and a life away from coding.

• The dB value comes directly from the FFT, for a RX signal it's the peak value of FFT bins inside the filter.
• FFT bins are affected by Windowing and selected FFT resolution, so different windowing / resolution will affect noise.
• SNR is peak as above, noise is the average of the lowest 10% (I think) of FFT bins displayed in the main window.
• When there's no visible signal there will still be a peak as you observe and noise is not uniform.

Simon Brown, G4ELI

https://www.sdr-radio.com

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Conrad, PA5Y
Sent: 03 July 2021 09:02
To: main@SDR-Radio.groups.io
Subject: [SDR-Radio] SNR meter, bandwidth and gain adjustment for transverters

Hello Simon.

I asked about the main dB scale in the receiver window and how it relates to bandwidth, you did not reply. I see that the question has been asked before, What exactly does it display? Also, the SNR reading does not change with filter BW, surely it should. How does the SNR meter work? For instance, it shows a positive SNR where there is no signal present in the filter passband so perhaps it is finding the max a signal in a wide passband? It would be better if it only looked inside the filter BW.

Finally, as a feature request would it be possible to have some manual gain adjustment to compensate for transverters and LNAs?

Many thanks

Conrad PA5Y

--

On Sat, Jul 3, 2021 at 09:01 AM, Conrad, PA5Y wrote:

Finally, as a feature request would it be possible to have some manual gain adjustment to compensate for transverters and LNAs?

Hi Conrad

I am no expert..... in fact very far from it, but have you seen the Visual Gain setting? It's available on all the rigs I use with SDRC (HL2, RSP2Pro, RTL-SDR V3). Not sure if Simon has implemented it for every radio that can be used with SDRC as it's in different place depending on the radio? Here it is for HL2 and RSP2Pro:

   

Can calibrate for zero signal (i.e.antenna disconnected). Is the feature you are alluding to?

73

Max

On Sat, Jul 3, 2021 at 09:01 AM, Conrad, PA5Y wrote:

Finally, as a feature request would it be possible to have some manual gain adjustment to compensate for transverters and LNAs?

Hi Conrad

I am no expert..... in fact very far from it, but have you seen the Visual Gain setting? It's available on all the rigs I use with SDRC (HL2, RSP2Pro, RTL-SDR V3). Not sure if Simon has implemented it for every radio that can be used with SDRC as it's in different place depending on the radio? Here it is for HL2 and RSP2Pro:

   

Can calibrate for zero signal (i.e.antenna disconnected). Is the feature you are alluding to?

73

Max

On Sat, Jul 3, 2021 at 10:04 AM, Conrad, PA5Y wrote:

Hello Max, not quite at least I don’t think so. Does this affect the metering?

Simon, yes, that's what I was not sure about!

Conrad...... if you have the Visual Gain feature for your radio, yes it does. What is (are) the radio(s)?

Max

Hello Max I am using a Perseus, where do I find it if it is there?

Regards

Conrad

On Sat, Jul 3, 2021 at 10:04 AM, Conrad, PA5Y wrote:

Hello Max, not quite at least I don’t think so. Does this affect the metering?

Simon, yes, that's what I was not sure about!

Conrad...... if you have the Visual Gain feature for your radio, yes it does. What is (are) the radio(s)?

Max

Hello Simon.

I asked about the main dB scale in the receiver window and how it relates to bandwidth, you did not reply. I see that the question has been asked before, What exactly does it display? Also, the SNR reading does not change with filter BW, surely it should. How does the SNR meter work? For instance, it shows a positive SNR where there is no signal present in the filter passband so perhaps it is finding the max a signal in a wide passband? It would be better if it only looked inside the filter BW.

Finally, as a feature request would it be possible to have some manual gain adjustment to compensate for transverters and LNAs?

Many thanks 

Conrad PA5Y

On Sat, Jul 3, 2021 at 10:22 AM, Conrad, PA5Y wrote:

I don’t think that I have that, I have the radio pane docked and I do not see it.

 

Regards

 

Conrad

According to this post, yes it does:

https://forum.sdr-radio.com:4499/viewtopic.php?f=18&t=916



Max

[Edited Message Follows]
[Reason: Fix url]

On Sat, Jul 3, 2021 at 11:46 AM, Conrad, PA5Y wrote:

Hello Max, I do not know how to get those options on the ribbon but I did find visual gain in the radio configuration tab. I am using v3.0.26

Hi Conrad

Not at all sure why you would be using 3.0.26? We're all on 3.0.28 now (released couple days ago). You really do need to use latest version. Simon is constantly working on it (yes, I do mean CONSTANTLY, as the man does not seem to sleep!) and adding highly effective tweaks almost daily to the test version. Remember he is only one person. What he has achieved with SDRC from the hands and brain of one man is nothing short of amazing. And also remember he makes it available  FREE although also consider a donation. Most of us (I hope) do. I only mention this as I know Simon will not:

https://www.sdr-radio.com/download#Donate

Anyway, at the least I suggest you do immediate update to 3.0.28. You should see some nice surprises!

https://www.sdr-radio.com/download

73

Max

Hi Alan, sorry I was not moaning, I just wanted to know what could be done. I use Linrad for measurements but really like the UI, appearance and stability of SDR console. I use it in conjunction with my K3S and transverters and for that purpose it is absolutely perfect. Off outside to do more antenna work.

Regards 

Conrad

-----Original Message-----
From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Alan G4ZFQ via groups.io
Sent: 03 July 2021 12:40
To: main@SDR-Radio.groups.io
Subject: Re: [SDR-Radio] SNR meter, bandwidth and gain adjustment for transverters


 > The signal level meter gives a rough number for the 59 boys.

I expected Joanne to make a comment:-)
There was a discussion a few months back where it was decided there was better software for scientific measurements.
You may find it a failing but there are so many other features in Simon's software that are not available elsewhere.

Alan

SDRC is "fashionably" misperforming with regards to signal level measurement, perhaps to stop some other questions about signal level measurement.

{^_-}

Hi Alan, sorry I was not moaning, I just wanted to know what could be done. I use Linrad for measurements but really like the UI, appearance and stability of SDR console. I use it in conjunction with my K3S and transverters and for that purpose it is absolutely perfect. Off outside to do more antenna work.

Regards 

Conrad

-----Original Message-----

From: main@SDR-Radio.groups.io <main@SDR-Radio.groups.io> On Behalf Of Alan G4ZFQ via groups.io

Sent: 03 July 2021 12:40

To: main@SDR-Radio.groups.io

Subject: Re: [SDR-Radio] SNR meter, bandwidth and gain adjustment for transverters

 > The signal level meter gives a rough number for the 59 boys.

I expected Joanne to make a comment:-)

There was a discussion a few months back where it was decided there was better software for scientific measurements.

You may find it a failing but there are so many other features in Simon's software that are not available elsewhere.

Alan