Since I know just enough about electronics to be a hazard, I need some help from the avionics gurus. I want to install a mute button for the comm radio output from my 650. If I used a DPST switch for this, I'd need to shunt the audio into a resistor to provide a load, right? The GTN-650 installation manual says that it supplies 100mw into a 500 ohm load. So, I'm thinking that bridging a resistor with those specs across one pole of the mute switch would work? Am I even close?