For whatever reason, designers of audio panels with marker beacon receivers in them never seem to do the obvious and put a BNC connector on the back (as you'd find with a comm radio, GPS, etc). That means you have to fabricate an adapter to go from the antenna coax to the D-sub pins on the back of the audio panel:
Here's a closer look… the center conductor is spliced to a 22 AWG wire, and another one is soldered to the shield. A female BNC connector is crimped onto the other end, and then I put heatshrink over the joint. What makes it a little harder is that the butt splice can't withstand the heat used to shrink the solder sleeve (ask me how I found out) so the order of operations gets a little fiddly.
I haven't run any antenna coax yet, of course, but this is just one more little item on my to-do list.