Mute doesn't, well, mute...

[Max]

PS: Back of the napkin analysis.
8 bits sampling is about 50 dB of dynamic range for the raw sampling.
At 2.4 Mbps (the one true usable sample rate) and a 100 Hz RX bandwidth you get another roughly 44 dB, So there is a total 94 dB of dynamic range. So it is very likely that being able to receive a weak signal in a system with perhaps an effective 30 dB noise figure, depending on operating frequency, means reception down to about 124 dBm and an overload signal well above -34 dBm has hte rtl dongle overloaded badly on transmit. It has quit sending useful or accurate data to properly trigger mute on a 1W signal with 60 dB isolation, -30 dBm.

I think Wes is using RSP Duo Joanne but same may apply with RF gain set so high? Although Wes says he has tried many different gain settings. Like you, need to see the screengrabs to go any further as I don't feel we are seeing the full story?

Wes already posted some screenshots before back in February:
https://forum.sdr-radio.com:4499/viewto ... 9693#p9693

First thing I noticed was running very old SDRC v3.1, but he since says he has updated to 3.3 Beta and same thing. Odd.

Actually Wes I wonder if a complete uninstall and fresh reinstall of 3.3 Beta might do the trick.

Max

[jdow]

Actually I suspect we both are making assumptions here that are possibly wrong. Nowhere has the gentleman remarked about his front end de guerre. That can make a very big difference.

Now, numbers that might be interesting are the signal strength on the S-Meter and spectrum display both for very strong signals and for his transmitter. (four values)

Pictures done properly contain information. Information here is critical. And it's being doled out in thimble fulls at best.

{^_^}

[w3kw]

My transmitter (one off many) is torn down for restoration and in a pile of parts on my bench. The next time I set up to transmit, I’ll take some screen grabs. I will also use a QRP rig (5 watts or less) for comparison. Again, I’m using the SDRDuo, MFJ 1708B RF relay, the DX engineering receiver guard and the most current SDR Console firmware available. The mute works during regular receive operation. All signals mute as they should if I set the mute level above ambient receive. When transmitting, all signals mute except my transmitted signal.

I’ll take photos of each combination of RF Gain, IF Gain, Mute settings, AGC selections, etc.

Thanks for the interest in helping with issue and happy holidays to all.

Wes

[jdow]

Bingo - with the explanation all in one place and with the added information my memory got keyed.

On the transmit panel look for what I have outlined in red. If either of those monitors are on results could be counter your expectations. The monitor function set on for TX could give you what you are hearing, I believe.

TX Panel.jpg (85.1 KiB) Viewed 894 times

{^_^}

[Max]

Bingo - with the explanation all in one place and with the added information my memory got keyed.

On the transmit panel look for what I have outlined in red. If either of those monitors are on results could be counter your expectations. The monitor function set on for TX could give you what you are hearing, I believe.

TX Panel.jpg

{^_^}

I had thought of that Joanne because I use that monitor all the time with digi modes, but he did clearly state that he can still see s9+++ signal on the spectrum/waterfall so I ruled that one out? Unless I misinterpreted his description?

73

Max

[Max]

On the transmit panel look for what I have outlined in red. If either of those monitors are on results could be counter your expectations. The monitor function set on for TX could give you what you are hearing, I believe.

{^_^}

Also that panel is for monitoring audio input to the SDR, and he is using a separate boat anchor TX so AFAIK he would not (should not?) hear anything from that panel regardless of selection?

Max

[jdow]

Good point - pictures showing control settings tell the story. If he is monitoring at IF frequency of his transceiver, for example, it is unlikely he'll be able to use muting effectively, especially if his front end has an AGC of its own - but then the transceiver's IF would still be infected with the Transceiver's AGC.

{^_^}

[w3kw]

Mute Settings

Picture2.jpg (98.91 KiB) Viewed 855 times

Console not muting my strong signal

Picture1.jpg (105.42 KiB) Viewed 855 times

I played with all the settings tonight. No deal. It appears to mute all signals except my transmit signal. This was all through the MFJ-1708B SDR TX RF Switch and a DX engineering receiver guard. I also tried to transmit without the receiver guard and still no muting.

Thanks all.

Wes

[w3kw]

You van see my transmit signal inside the green area on the waterfall/FREQ display in the first photo.

[Max]

Picture2.jpg

Picture1.jpg

I played with all the settings tonight. No deal. It appears to mute all signals except my transmit signal. This was all through the MFJ-1708B SDR TX RF Switch and a DX engineering receiver guard. I also tried to transmit without the receiver guard and still no muting.

Thanks all.

Wes

Two things. Firstly can you please post the pictures as attachments instead of inserting them as images. It's a bit hard for me to read as I can't see the pictures full size..

Second thing that hit me. I don't have RSP Duo but I have RSP2Pro and also have played with some other RSP receivers on the servers and they seem about the same so I guess maybe the Duo is too...... you seem to have Visual Gain set high. IMO this will have the effect of limiting the dynamic range of the receiver.

Remove antenna from the Duo input while tuned t the frequency you intend to operate on. The RF and IF gain settings don't look too unreasonable. Can't quite see from the pics but looks like RF 4, IF -25. SO with antenna removed, then set Visual Gain to give S0 signal strength. Then reconnect antenna and try again.

Others opinion may differ, but to me it looks like with the Visual Gain setting as you have it (and remember this will affect trigger levels in the Mute control panel) there is quite possibly too little differential between normal RX signal level and the heavily overloaded receiver when in TX mode.

Maybe try that and see how you get on, and also with Visual Gain set this way, try the Mute with Peak enabled as well and with threshold levels set as recommended in the "Help" notes of the Mute panel.

73

Max