Re: Mute audio

Siegfried Jackstien

does it matter what radio he uses?? (guessing you think about cat command)

what about using the "tx in" signal that you now use for tx with pluto or lime (and that already does tx mute)

means ... mute rx volume (like you now do with the function mute rx when txing) when external ptt is switched on

we now use "cts" on a usb to ttl adaptor (pull to ground) to switch pluto or lime to tx (and when txing mute rx volume)

if you use THE SAME SIGNAL (cts) also on "receive only" sdr ... for muting the speaker ... problem would be solved easy

no need to mess around with cat etc ... just a signal pulled to ground ...

the parts are already there (the program parts that you use for tx and muting speaker) ...

just use same signal also on receive only sdr and were set

(and i can mute my speaker regardless if i use my pluto or an rtl dongle) ...

that should make a lot of setups possible ... especially combination of a normal rig (maybe without cat) together with an sdr (be it direct in parallel on antenna or on an if out port) ... muting via "ptt signal" (ftdi chip on usb port) would be an easy solution

and you already have all parts inside your soft :-)

greetz sigi dg9bfc

Am 26.03.2020 um 04:39 schrieb Simon Brown:



Which radio are you using?


Simon Brown, G4ELI


From: <> On Behalf Of Joe W4WT
Sent: 26 March 2020 03:04
Subject: Re: [SDR-Radio] Mute audio


HI Simon,

Let me explain what I'm doing and it will make more sense.  I am working linear satellites.  I am using SDRC (attached to an Rsp1a) as the downlink receiver for several reasons.  The antenna of the Rsp1a is attached to the downlink antenna.  I don't want to hear myself other than at the start of the pass to make sure I'm on frequency.  Listening to oneself and trying to talk when there is a noticeable delay is a bit much for an old guy like me.  Thus the desire for the mute function.  I use SatPC32 to control my radio and have DxLab Commander linked to it via DDE.  This allows DxLab to get both the satellite name and satellite mode automatically which are needed for a valid satellite qso as well as frequency information.  DxLab Commander is set up to use it's secondary port to control SDRC's frequency and mode via SDRC's CAT serial port function. 

All of this works perfectly and automatically (I love automation).  SDRC follows the radios VFO in this scenario allowing me to have a great panadapter and waterfall all following SatPC32's tracking.  The only thing missing is a mute line that I can actuate with the keying line from the rig.  Auto mute won't work in this scenario.  I use VOX and a boom mic/headset for handsfree operation.  This leaves my hands free to type in callsigns and log contacts and tune the VFO as needed.  This setup works about as well as I could hope for, other than the mute, but as I mentioned above, I can rig up a relay to handle it.
Hope that helps explain things,

Joe W4WT

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