For Any WinRadio G-31 Excalibur Users

[BOBRR]

Hi,

Please bear with me a bit on these two rather simplistic questions.
Have my WinRadio G31 Excaliburgoing again. Super radio.
It's been quite a while since last used, and at one time I probably understood this, but don't now.

a. I go to Manual Gain, and sure enough, the audio gets louder and softer going thru the values.

But this is not Audio Gain, but rather what is going into the DeMod. Right ?

So, shouldn't the the values of the peaks for the stations that show up (in any of the 3 windows)
become larger (more received amplitude) with increased Gain settings. They don't. Why ?

b. The SAM option:

When do you find it most useful ?
Any "tricks" in when, how, and where to best use it ?

Thanks, as always, for help,
Bob

 

[JerryX]

a. Yes, the manual gain setting affects what's going to the demodulator. The spectrum and waterfall displays do not reflect the gain setting, but show the actual signal strength.

b. SAM is useful when there's deep fading caused by propagation. For local MW AM stations during the day, it's not much use, but at night when AM stations are experiencing deep fades, SAM helps a lot. In SAM mode, you can choose to listen to both sidebands, or only the lower or upper sideband. This can help, for example, if you're listening to a station that's being interfered with by a strong station right below it in frequency--just turn off the lower sideband and the interfering station will go away.

 

[BOBRR]

Hi Jerry,

Thanks for info. Appreciated.

I guess regarding the "Gain" not having a "visual" effect on any of the windows is my
using SDRConsole, and the others, with my RSPdx, where changing the RF Gain
shows in the Spectrum window(s) the effect of doing so.

Really useful visual information re what's happening.

Sure wish there was something similar in the G-31 software. Terrific radio, though.

Thanks again; stay in touch.

Regards, stay safe,
Bob

 

[majoco]

I haven't downloaded your G31 software, but my G33 software is probably much about the same. Interesting little experiment - I usually run with the AGC on and the "Max gain" set to somewhere around 90dB - what this figure does is stop the gain going higher when there's a fade on an AM signal which brings up the background noise and avoids pumping on an SSB signal, although I have set a long time constant specifically for SSB and CW - according to the display my noise level is about -120dB. Interestingly, there's a figure alongside the "Manual gain" which is bouncing up and down with the AGC action. If I put the AGC speed to "Fast", then the manual gain number closely follows the "S" meter value. If I reduce the max gain as soon as I get to the same value as is shown alongside the Manual gain, then the AGC is rendered inoperable and the manual and max gain figures are the same, and then the signal starts level audio starts to drop - but the "S" meter and waterfall both remain the same. There is an explanation in the "Gain" section of "Function Tabs" in the help menu but it doesn't really say much - except that the "Ref Level" sets how much signal is sent to the demodulator. So it would appear that the waterfall and the spectrum displays are driven by a separate IF amplifier and the signal fed to the demodulator is controlled by the selectable AGC characteristics. I don't know how your waterfall works, but on a recent software update they introduced three controls for the waterfall display which I fiddle with often as the background noise changes. This is probably better than the waterfall signals fading in and out in sympathy with the fading signal that we are listening to.

I do agree with you - it's a great receiver!

 

[BOBRR]

I haven't downloaded your G31 software, but my G33 software is probably much about the same. Interesting little experiment - I usually run with the AGC on and the "Max gain" set to somewhere around 90dB - what this figure does is stop the gain going higher when there's a fade on an AM signal which brings up the background noise and avoids pumping on an SSB signal, although I have set a long time constant specifically for SSB and CW - according to the display my noise level is about -120dB. Interestingly, there's a figure alongside the "Manual gain" which is bouncing up and down with the AGC action. If I put the AGC speed to "Fast", then the manual gain number closely follows the "S" meter value. If I reduce the max gain as soon as I get to the same value as is shown alongside the Manual gain, then the AGC is rendered inoperable and the manual and max gain figures are the same, and then the signal starts level audio starts to drop - but the "S" meter and waterfall both remain the same. There is an explanation in the "Gain" section of "Function Tabs" in the help menu but it doesn't really say much - except that the "Ref Level" sets how much signal is sent to the demodulator. So it would appear that the waterfall and the spectrum displays are driven by a separate IF amplifier and the signal fed to the demodulator is controlled by the selectable AGC characteristics. I don't know how your waterfall works, but on a recent software update they introduced three controls for the waterfall display which I fiddle with often as the background noise changes. This is probably better than the waterfall signals fading in and out in sympathy with the fading signal that we are listening to.

I do agree with you - it's a great receiver!

 

[BOBRR]

Hi,

Thanks, all, for the help with this.
Am in my 80's now, and I miss many of the nuances, so will blame my ignorance on that.

Here's what is bothering me (a lot), and that I don't understand.

If I use my RSPdx with SDRConsole, or Uno, or any of the other SDR software packages, they
all have a (RF) Gain setting that is adjustable.
As one adjusts it, you see the level changes in the received signal(s) in the various windows.

Makes it nice to have this visual indication, as you can see when there is perhaps too much gain,
and the signals become distorted, etc.

But with the Excalibur, this visual indication, or even changing the RF Gain does not seem possible.

Yes, there is a AGC and/or a Manual Gain; the manual gain being a slider that certainly
does effect the Audio, but what else it does I'm not sure.
*What does it do ?

So,
Is there a way to see Gain changes on any of the windows ?

**If not, what is actually happening; is the Excalibur adjusting the RF Gain "automatically" ?

If someone could explain all of this for me, would be most appreciative. (I just don't find it intuitive)
I have read the Manual, many times, but still uncertain what is happening.

Much thanks, appreciate the help and explanations, very much,
Stay well,
Bob

 

[JerryX]

Bob,

You could request that Radixon change the software to allow the gain slider to affect the spectrum/waterfall, perhaps as a selectable option.

 

[BOBRR]

Hi,

Probably hopeless.
Updating their G-31 software doesn't exactly seem like a priority for them, unfortunately.

Stay in touch.

Best regards,
Bob