Max,
I’m on the road, but I will attempt to post more photos as attachments when I get the chance.
I’ve played with every slider option on the menu bar including visual gain. I don’t agree with how visual gain changes any of the receipt parameters as it should merrily change the picture you’re looking at, but it seems to do just that.
I adjusted RF gain, IF gain, AGC options, visual gain, etc., in every combination imaginable attempting to determine why sometimes it works perfectly, and then all of a sudden my transmit signal blast through. I will say that once the mute fails, it does not return at all. There were a few instances, while tuning the tank circuit of my transmitter, the SDR console would come in and out of mute. I’m wondering if there is a certain power level that convinces the SDR console to mute eventually. So far it’s a real mystery, but it works. It’s really brilliant. The SR is a very capable platform and combines nicely with anchor transmitters.
Thanks again,
Wes.
Mute doesn't, well, mute...
Re: Mute doesn't, well, mute...
Hi Wes. Unfortunately that's incorrect. The visual gain is not purely visual. It does have an effect on all of the gains in the DSP signal chain including the muting as the Visual Gain setting is applied before all the other DSP chain gain stages. It's a subject that has been discussed at length but it is how Simon has implemented it. Rather than "Visual Gain" it might possibly be better entitled "Calibration Gain". But no, it certainly has the ability to have a major effect on how the muting works.
Just to be 100% sure I am right on this I have just checked and it does indeed affect the mute settings in the setup panel as I have described. To prove it, set a low mute level, tune in a strong received signal then vary the Visual Gain up and down. You will be able to mute and unmute the station using just the Visual Gain (as I just tested).
So I strongly suggest that anyway, as good practice, you "calibrate" the Visual Gain to be S0 with no antenna attached and then try with the suggested mute settings in the Mute options panel. It may have no effect but it cannot possibly do any harm. By having Visual Gain set too high (as I think you may have) IMO you could be greatly compressing the differential between received signals and the TX signal.
You need to do this calibration after setting the RSP Radio Gains to approximately what you usually use, but I think you are probably OK as a starting point with the aforementioned RF4 and IF -25 dB if my RSP2Pro is any guide. I am 90% sure your muting issues will be gain settings related especially as you say you have had it working at some point.
73
Max
Re: Mute doesn't, well, mute...
Max is correct about attachment vs inline. (raises small me2 hand.) {^_-}
Set visual gain to zero. Make it work. Then see what happens when you play with visual gain. I'd also suggest eschewing S9 type S-meter display and select the dBm display. I don't remember if that leaves S-Meter and mute setting on the same scale or not. I hope it does. With settings neutered this way you can probably make muting work. Note your S-Meter reading (which looks quite low, I think - fuzzy picture problems) seems to be lower than I'd expect. You might have too little leakage for it to work nicely for you, which is a bit of a surprise. That may, however, be an artifact of the Visual Gain setting. I've had trouble here with settings beyond the +/- 20 dB range. It is easy to see if this is the case once you have some predictable performance with neutral settings.
BTW - very roughly speaking the noise level for 3 kHz SSB on a 50 ohm dummy load on the receiver input is pretty close to -130 dBm. (Presume 6 dB noise figure and Boltzmann noise. That would be +6 dB - 174 dBm + 35 dB = -130 dBm.) But, I'd not fuss with that. Ham signal strengths are "S9+111.2 dB my friend." That is especially true on most rice boxes that get calibrated as badly as 2dB per S-unit.
Considering this when you connect a good antenna your noise level will increase up to about 40 dB depending on frequency. So input attenuation is a good thing. It effectively increases your dynamic range. Adding attenuation until the SNR gets worse is a reasonable input attenuation setting. Maybe back off 5 dB on the attenuation for the sweet spot.
{^_^}
Set visual gain to zero. Make it work. Then see what happens when you play with visual gain. I'd also suggest eschewing S9 type S-meter display and select the dBm display. I don't remember if that leaves S-Meter and mute setting on the same scale or not. I hope it does. With settings neutered this way you can probably make muting work. Note your S-Meter reading (which looks quite low, I think - fuzzy picture problems) seems to be lower than I'd expect. You might have too little leakage for it to work nicely for you, which is a bit of a surprise. That may, however, be an artifact of the Visual Gain setting. I've had trouble here with settings beyond the +/- 20 dB range. It is easy to see if this is the case once you have some predictable performance with neutral settings.
BTW - very roughly speaking the noise level for 3 kHz SSB on a 50 ohm dummy load on the receiver input is pretty close to -130 dBm. (Presume 6 dB noise figure and Boltzmann noise. That would be +6 dB - 174 dBm + 35 dB = -130 dBm.) But, I'd not fuss with that. Ham signal strengths are "S9+111.2 dB my friend." That is especially true on most rice boxes that get calibrated as badly as 2dB per S-unit.
Considering this when you connect a good antenna your noise level will increase up to about 40 dB depending on frequency. So input attenuation is a good thing. It effectively increases your dynamic range. Adding attenuation until the SNR gets worse is a reasonable input attenuation setting. Maybe back off 5 dB on the attenuation for the sweet spot.
{^_^}