FWIW, I agree that the PCAS should come first. If nothing else, it
will teach you how to do a better scan. Airplanes are sometimes very
hard to see in flight, but if you absolutely know something is out
there you'll quickly learn how to look harder and better.

After two years with the MRX, I realized that while I was alerted to
other traffic (carrying transponders) they might be unaware of me. So
I installed a Becker ATC-4401-175. I have seen aircraft change their
course slightly to avoid me since the transponder went in, thus
proving its value.

I mounted my Zaon MRX in my ASW-19s panel, just under the top arch.
It's protected from the sun by the overhang of the glare shield, is
right in my field of vision, and is powered by the ship's battery. I
have no problem hearing its advisory or alert beeps, and there is no
radio interference.

Again FWIW, I use an 18" length of cable to extend the (stock) antenna
forward of the instrument panel. The antenna is midway between the
panel and the rudder pedals, right under the glare shield. It seems to
work just fine. The reason I moved it away from the MRX is because I
didn't want to poke it through the glare shield.

-John