I'm looking for a radio for a Challenger II. I am wondering if
someone can give me some advice between a Apollo SL-40 and a XCom760.

We've got an SL-30 nav/comm in our plane and love it. It has a digital
signal processor in it and can listen on one freq, and when nothing is
going on, let you listen to a 2nd freq. Use that feature all the time,
and much prefer that to two simultaneous comm radios. Don't know how
many stored freqs the SL-40 has (please don't say 760...), but we also
have our SL-30 get freqs from the GPS. That's way cool, too.

The only shortcoming is that some microphones (Lightspeed) work, but not
superbly, with the unit.

Don't know squat about the Xcom.

Ed Wischmeyer