I just looked at the manual and it looks like the preamp is only for the VHF input. Maybe you have to be tuned to vhf for the preamp control to appear. Just guessing since I don't have an S3.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Saturday, January 14, 2023 9:56 AM
To: ELADSDR@groups.io <ELADSDR@groups.io>
Subject: [EladSDR] #ELADSW2 SW-2 Software

 

Could someone please tell me where the PREAMP button is on SW-2?

 

Everett N4CY

Could someone please tell me where the PREAMP button is on SW-2?

 

Everett N4CY

On 14 Jan 2023, at 20:06, Everett N4CY via groups.io <everettsharp@...> wrote:



I have spent most of the day comparing the sensitivity of several SDR Receivers and a Icom 8600 on SDRC using a Rigol DSG821 signal generator and two MiniCircuit 20dB attenuators , thus allowing me to be able to go down -150dBm. I used a 1,000kHz tone for all of the test.

 

 After finishing the evaluation I decided to look at my ELAD FDM –S3 on the SW-2  software.

The procedure that I used to evaluate at the sensitivity of the receivers was to use CW mode with a 600kHz BW and I would keep lowering the signal level until I could no longer see it on the waterfall and then increase the signal until I could see the signal again on the waterfall.

 

So with SDRC and the ELAD FDM-S3  I had a visible signal on the waterfall at -141dBm. I then tried the S3 on SW-2 V 3.55 software using the same procedure (using  500kHz BW in CW mode, no attenuation, or filters) I saw a visible signal on the waterfall  at -125dBM

 Something is not quite right with SW-2 V3.55 software, as there should not be a 16dB difference between the two software programs .

 

That is a loss of 16dB of sensitivity using SW-2 software

 

Everett N4CY

_._,

Did you have the waterfall on SW2 set for maximum gain? Setting the upper and lower limits in the waterfall side sliders about 12dB apart usually gives best contrast for weak signals. What S/N ratio was reported by the SW2 advanced marker measurement display at RF and IF? What is the indicated level of band noise according to SW2? Is the attenuator definitely off in SW2? What is the bin size in the two programs? Usually at 192kHz BW, SW2 has 11.7 Hz bins.

Does the minimum discernible signal in headphones have the same difference between the two programs? 

Any weird offsets configured in SW2? 

If you send the output of the two programs to something like Spectrum Lab or Spectran or a spectrum analyser app, do you need to boost the signal by the same difference to get an identical result?

Something is certainly weird.

Good luck

Neil G4DBN

On 14 Jan 2023, at 20:06, Everett N4CY via groups.io <everettsharp@...> wrote:



I have spent most of the day comparing the sensitivity of several SDR Receivers and a Icom 8600 on SDRC using a Rigol DSG821 signal generator and two MiniCircuit 20dB attenuators , thus allowing me to be able to go down -150dBm. I used a 1,000kHz tone for all of the test.

 

 After finishing the evaluation I decided to look at my ELAD FDM –S3 on the SW-2  software.

The procedure that I used to evaluate at the sensitivity of the receivers was to use CW mode with a 600kHz BW and I would keep lowering the signal level until I could no longer see it on the waterfall and then increase the signal until I could see the signal again on the waterfall.

 

So with SDRC and the ELAD FDM-S3  I had a visible signal on the waterfall at -141dBm. I then tried the S3 on SW-2 V 3.55 software using the same procedure (using  500kHz BW in CW mode, no attenuation, or filters) I saw a visible signal on the waterfall  at -125dBM

 Something is not quite right with SW-2 V3.55 software, as there should not be a 16dB difference between the two software programs .

 

That is a loss of 16dB of sensitivity using SW-2 software

 

Everett N4CY

_._,

On 14 Jan 2023, at 20:36, Everett N4CY via groups.io <everettsharp@...> wrote:

 Hi Neal,

I will look at it again tomorrow, I am done for the day. I did use the slider on the left side of the waterfall and had it adjusted to the point that there was some noise showing in the waterfall. I also listen for a tone which was head with in 1dB of the signal on the waterfall..

Everett N4CY

Sent from the all new AOL app for iOS

On Saturday, January 14, 2023, 2:24 PM, Neil Smith G4DBN <neil@...> wrote:

Did you have the waterfall on SW2 set for maximum gain? Setting the upper and lower limits in the waterfall side sliders about 12dB apart usually gives best contrast for weak signals. What S/N ratio was reported by the SW2 advanced marker measurement display at RF and IF? What is the indicated level of band noise according to SW2? Is the attenuator definitely off in SW2? What is the bin size in the two programs? Usually at 192kHz BW, SW2 has 11.7 Hz bins.

Does the minimum discernible signal in headphones have the same difference between the two programs? 

Any weird offsets configured in SW2? 

If you send the output of the two programs to something like Spectrum Lab or Spectran or a spectrum analyser app, do you need to boost the signal by the same difference to get an identical result?

Something is certainly weird.

Good luck

Neil G4DBN

On 14 Jan 2023, at 20:06, Everett N4CY via groups.io <everettsharp@...> wrote:



I have spent most of the day comparing the sensitivity of several SDR Receivers and a Icom 8600 on SDRC using a Rigol DSG821 signal generator and two MiniCircuit 20dB attenuators , thus allowing me to be able to go down -150dBm. I used a 1,000kHz tone for all of the test.

 

 After finishing the evaluation I decided to look at my ELAD FDM –S3 on the SW-2  software.

The procedure that I used to evaluate at the sensitivity of the receivers was to use CW mode with a 600kHz BW and I would keep lowering the signal level until I could no longer see it on the waterfall and then increase the signal until I could see the signal again on the waterfall.

 

So with SDRC and the ELAD FDM-S3  I had a visible signal on the waterfall at -141dBm. I then tried the S3 on SW-2 V 3.55 software using the same procedure (using  500kHz BW in CW mode, no attenuation, or filters) I saw a visible signal on the waterfall  at -125dBM

 Something is not quite right with SW-2 V3.55 software, as there should not be a 16dB difference between the two software programs .

 

That is a loss of 16dB of sensitivity using SW-2 software

 

Everett N4CY

_._,

 

If you drag the top of the slider bar down, the contrast rises. Useful for very weak signals but if the difference is still apparent in headphones then it's going to be a different problem

Neil

On 14 Jan 2023, at 20:36, Everett N4CY via groups.io <everettsharp@...> wrote:

Hi Neal,

 

I will look at it again tomorrow, I am done for the day. I did use the slider on the left side of the waterfall and had it adjusted to the point that there was some noise showing in the waterfall. I also listen for a tone which was head with in 1dB of the signal on the waterfall..

 

Everett N4CY

 

 

Sent from the all new AOL app for iOS

On Saturday, January 14, 2023, 2:24 PM, Neil Smith G4DBN <neil@...> wrote:

 

Did you have the waterfall on SW2 set for maximum gain? Setting the upper and lower limits in the waterfall side sliders about 12dB apart usually gives best contrast for weak signals. What S/N ratio was reported by the SW2 advanced marker measurement display at RF and IF? What is the indicated level of band noise according to SW2? Is the attenuator definitely off in SW2? What is the bin size in the two programs? Usually at 192kHz BW, SW2 has 11.7 Hz bins.

 

Does the minimum discernible signal in headphones have the same difference between the two programs? 

 

Any weird offsets configured in SW2? 

 

If you send the output of the two programs to something like Spectrum Lab or Spectran or a spectrum analyser app, do you need to boost the signal by the same difference to get an identical result?

 

Something is certainly weird.

 

Good luck

Neil G4DBN

On 14 Jan 2023, at 20:06, Everett N4CY via groups.io <everettsharp@...> wrote:

I have spent most of the day comparing the sensitivity of several SDR Receivers and a Icom 8600 on SDRC using a Rigol DSG821 signal generator and two MiniCircuit 20dB attenuators , thus allowing me to be able to go down -150dBm. I used a 1,000kHz tone for all of the test.

 

 After finishing the evaluation I decided to look at my ELAD FDM –S3 on the SW-2  software.

The procedure that I used to evaluate at the sensitivity of the receivers was to use CW mode with a 600kHz BW and I would keep lowering the signal level until I could no longer see it on the waterfall and then increase the signal until I could see the signal again on the waterfall.

 

So with SDRC and the ELAD FDM-S3  I had a visible signal on the waterfall at -141dBm. I then tried the S3 on SW-2 V 3.55 software using the same procedure (using  500kHz BW in CW mode, no attenuation, or filters) I saw a visible signal on the waterfall  at -125dBM

 Something is not quite right with SW-2 V3.55 software, as there should not be a 16dB difference between the two software programs .

 

That is a loss of 16dB of sensitivity using SW-2 software

 

Everett N4CY

_._,

 

But SDR Console isn't calibrated correctly.

 

Simon Brown

https://g4eli.com

https://sdr-radio.com

 

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: 15 January 2023 15:11
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software

 

Hi Neal,

 

I see now what the problem is, but don't know how to correct it. I terminated the S3 with a 50 ohm load and the noise floor on SDRC  is -145dB , the noise floor on SW-2 swings from -126 to -130dB

 

Everett N4CY

In a message dated 1/14/2023 2:41:58 PM Central Standard Time, neil@... writes:

 

 

If you drag the top of the slider bar down, the contrast rises. Useful for very weak signals but if the difference is still apparent in headphones then it's going to be a different problem

Neil

On 14 Jan 2023, at 20:36, Everett N4CY via groups.io <everettsharp@...> wrote:

Hi Neal,

 

I will look at it again tomorrow, I am done for the day. I did use the slider on the left side of the waterfall and had it adjusted to the point that there was some noise showing in the waterfall. I also listen for a tone which was head with in 1dB of the signal on the waterfall..

 

Everett N4CY

 

 

Sent from the all new AOL app for iOS

On Saturday, January 14, 2023, 2:24 PM, Neil Smith G4DBN <neil@...> wrote:

 

Did you have the waterfall on SW2 set for maximum gain? Setting the upper and lower limits in the waterfall side sliders about 12dB apart usually gives best contrast for weak signals. What S/N ratio was reported by the SW2 advanced marker measurement display at RF and IF? What is the indicated level of band noise according to SW2? Is the attenuator definitely off in SW2? What is the bin size in the two programs? Usually at 192kHz BW, SW2 has 11.7 Hz bins.

 

Does the minimum discernible signal in headphones have the same difference between the two programs? 

 

Any weird offsets configured in SW2? 

 

If you send the output of the two programs to something like Spectrum Lab or Spectran or a spectrum analyser app, do you need to boost the signal by the same difference to get an identical result?

 

Something is certainly weird.

 

Good luck

Neil G4DBN

On 14 Jan 2023, at 20:06, Everett N4CY via groups.io <everettsharp@...> wrote:

I have spent most of the day comparing the sensitivity of several SDR Receivers and a Icom 8600 on SDRC using a Rigol DSG821 signal generator and two MiniCircuit 20dB attenuators , thus allowing me to be able to go down -150dBm. I used a 1,000kHz tone for all of the test.

 

 After finishing the evaluation I decided to look at my ELAD FDM –S3 on the SW-2  software.

The procedure that I used to evaluate at the sensitivity of the receivers was to use CW mode with a 600kHz BW and I would keep lowering the signal level until I could no longer see it on the waterfall and then increase the signal until I could see the signal again on the waterfall.

 

So with SDRC and the ELAD FDM-S3  I had a visible signal on the waterfall at -141dBm. I then tried the S3 on SW-2 V 3.55 software using the same procedure (using  500kHz BW in CW mode, no attenuation, or filters) I saw a visible signal on the waterfall  at -125dBM

 Something is not quite right with SW-2 V3.55 software, as there should not be a 16dB difference between the two software programs .

 

That is a loss of 16dB of sensitivity using SW-2 software

 

Everett N4CY

_._,

 

 

 

Exeactly! In SDR Console you will find the "Resolution" controls in the VIEW menu. This setting combined with the waterfall speed selection will alter the FFT bin size which can be displayed by enabling the statsitics display. At low resolution (large bins) the noise floor moves up while the tones stay fixed. In SW2, the resolution is different between the IF and main windows and the zoom controls affect it. I have managed to get a 2.9hz bin sine in SW2 IF window and also in SDRC before, but SDRC has changed in the past few months and now the closest I can get is 3.1Hz. This can be tricky. Also, the spectrum display may not correspond with the FFT bin in the waterfall (In SDRC for sure). So assessing the noise floor in the spectrum can be misleading.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Alberto I2PHD <i2phd@...>
Sent: Sunday, January 15, 2023 8:20 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Everett, which was the FFT resolution that you used both in SDRC and in FDM-SW2 ?
The minimum discernible signal on the waterfall (mind, the audio is not affected, just the waterfall...) is a direct function of the FFT bin size.
If you do not set on both programs the *same* FFT resolution (bin size) any comparison is meaningless.

73  Alberto  I2PHD

You said that you adjusted the contrast/brightness until the noise was just visible. That is where you encounter the noise floor. If the bin size is small, you will be able to increase the brightness/contrast much further before seeing the noise floor. Then you will see a weaker signal.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Sunday, January 15, 2023 9:31 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Tony,

 

I will get off of the noise floor. The numbers I am using for the sensitivity between the SW-2 and SDRC are from the signal generator. So again I am seeing and hearing the tone from the signal generator on SDRC at -141dBM and on SW-2 it is -125dBm.

 

Everett

In a message dated 1/15/2023 10:15:19 AM Central Standard Time, canthony15@... writes:

 

Exeactly! In SDR Console you will find the "Resolution" controls in the VIEW menu. This setting combined with the waterfall speed selection will alter the FFT bin size which can be displayed by enabling the statsitics display. At low resolution (large bins) the noise floor moves up while the tones stay fixed. In SW2, the resolution is different between the IF and main windows and the zoom controls affect it. I have managed to get a 2.9hz bin sine in SW2 IF window and also in SDRC before, but SDRC has changed in the past few months and now the closest I can get is 3.1Hz. This can be tricky. Also, the spectrum display may not correspond with the FFT bin in the waterfall (In SDRC for sure). So assessing the noise floor in the spectrum can be misleading.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Alberto I2PHD <i2phd@...>
Sent: Sunday, January 15, 2023 8:20 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Everett, which was the FFT resolution that you used both in SDRC and in FDM-SW2 ?
The minimum discernible signal on the waterfall (mind, the audio is not affected, just the waterfall...) is a direct function of the FFT bin size.
If you do not set on both programs the *same* FFT resolution (bin size) any comparison is meaningless.

73  Alberto  I2PHD

 

 

For audio, the filter bandwidth, whether you have the peaking filter enabled in SDRC, how the AGC is set up, if you have the equalizer enabled etc all affect what you can hear. 

 

For me, I have bad hearing so I decode NDBs on the waterfall and I am very familiar with weak signals displayed visually. I was just conveying some of that experience to you.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Sunday, January 15, 2023 9:45 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Tony,

 

Remember I was listing to the tone too.

 

Everett

In a message dated 1/15/2023 10:39:11 AM Central Standard Time, canthony15@... writes:

 

You said that you adjusted the contrast/brightness until the noise was just visible. That is where you encounter the noise floor. If the bin size is small, you will be able to increase the brightness/contrast much further before seeing the noise floor. Then you will see a weaker signal.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Sunday, January 15, 2023 9:31 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Tony,

 

I will get off of the noise floor. The numbers I am using for the sensitivity between the SW-2 and SDRC are from the signal generator. So again I am seeing and hearing the tone from the signal generator on SDRC at -141dBM and on SW-2 it is -125dBm.

 

Everett

In a message dated 1/15/2023 10:15:19 AM Central Standard Time, canthony15@... writes:

 

Exeactly! In SDR Console you will find the "Resolution" controls in the VIEW menu. This setting combined with the waterfall speed selection will alter the FFT bin size which can be displayed by enabling the statsitics display. At low resolution (large bins) the noise floor moves up while the tones stay fixed. In SW2, the resolution is different between the IF and main windows and the zoom controls affect it. I have managed to get a 2.9hz bin sine in SW2 IF window and also in SDRC before, but SDRC has changed in the past few months and now the closest I can get is 3.1Hz. This can be tricky. Also, the spectrum display may not correspond with the FFT bin in the waterfall (In SDRC for sure). So assessing the noise floor in the spectrum can be misleading.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Alberto I2PHD <i2phd@...>
Sent: Sunday, January 15, 2023 8:20 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Everett, which was the FFT resolution that you used both in SDRC and in FDM-SW2 ?
The minimum discernible signal on the waterfall (mind, the audio is not affected, just the waterfall...) is a direct function of the FFT bin size.
If you do not set on both programs the *same* FFT resolution (bin size) any comparison is meaningless.

73  Alberto  I2PHD

 

 

 

 

Attached is a screenshot of SW2 receiving a -140dbm tone from my Boonton 103D. The gen is set at -100dbm and I have an HP step atten set to 40db at the receiver. The IF display says it is running .4hz bins and the main display says it has 23hz bins. The IF display clearly has better SNR. This is with my S2.

 

BTW, in case you did not see it, Simon posted a build with a fix for the S3 with a 16db reduction for the S3.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Sunday, January 15, 2023 10:14 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Tony,

 

I could be all wrong with my findings, but 16dB of difference is hard to explain?

 

Everett N4CY

In a message dated 1/15/2023 11:01:31 AM Central Standard Time, canthony15@... writes:

 

For audio, the filter bandwidth, whether you have the peaking filter enabled in SDRC, how the AGC is set up, if you have the equalizer enabled etc all affect what you can hear. 

 

For me, I have bad hearing so I decode NDBs on the waterfall and I am very familiar with weak signals displayed visually. I was just conveying some of that experience to you.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Sunday, January 15, 2023 9:45 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Tony,

 

Remember I was listing to the tone too.

 

Everett

In a message dated 1/15/2023 10:39:11 AM Central Standard Time, canthony15@... writes:

 

You said that you adjusted the contrast/brightness until the noise was just visible. That is where you encounter the noise floor. If the bin size is small, you will be able to increase the brightness/contrast much further before seeing the noise floor. Then you will see a weaker signal.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Everett N4CY via groups.io <everettsharp@...>
Sent: Sunday, January 15, 2023 9:31 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Tony,

 

I will get off of the noise floor. The numbers I am using for the sensitivity between the SW-2 and SDRC are from the signal generator. So again I am seeing and hearing the tone from the signal generator on SDRC at -141dBM and on SW-2 it is -125dBm.

 

Everett

In a message dated 1/15/2023 10:15:19 AM Central Standard Time, canthony15@... writes:

 

Exeactly! In SDR Console you will find the "Resolution" controls in the VIEW menu. This setting combined with the waterfall speed selection will alter the FFT bin size which can be displayed by enabling the statsitics display. At low resolution (large bins) the noise floor moves up while the tones stay fixed. In SW2, the resolution is different between the IF and main windows and the zoom controls affect it. I have managed to get a 2.9hz bin sine in SW2 IF window and also in SDRC before, but SDRC has changed in the past few months and now the closest I can get is 3.1Hz. This can be tricky. Also, the spectrum display may not correspond with the FFT bin in the waterfall (In SDRC for sure). So assessing the noise floor in the spectrum can be misleading.

 

Tony

 

---

From: EladSDR@groups.io <EladSDR@groups.io> on behalf of Alberto I2PHD <i2phd@...>
Sent: Sunday, January 15, 2023 8:20 AM
To: EladSDR@groups.io <EladSDR@groups.io>
Subject: Re: [EladSDR] #ELADSW2 SW-2 Software #eladsw2

 

Everett, which was the FFT resolution that you used both in SDRC and in FDM-SW2 ?
The minimum discernible signal on the waterfall (mind, the audio is not affected, just the waterfall...) is a direct function of the FFT bin size.
If you do not set on both programs the *same* FFT resolution (bin size) any comparison is meaningless.

73  Alberto  I2PHD