Hello from Sweden!
The linear has an input to get it on air by shorting the input to ground.

The input has +5 volt in open state.

If i connect it to Sun SDR2 Pro EXT CTRL Pin Name X8 it will not work if I press PA on the main window and MOX to go on air.

Will open collector on X8 accept +5 Volt?
/Folke

Hi!

I had the HL300V for short period of time. It worked fine without connecting anything besides RF cable (from SunSdr2 to PA).
I used auto band switching and it worked OK. No PTT conection, it detects RF - it's kind a VOX on PA.