I mounted a surface-mount sirius antenna on top of my tower, a flight control tower for an SV211.
In these pictures, the tower is folded down, which is how I had the tower when I mounted the antenna.
The surface-mount antenna has a bayonet connector for the antenna wire, so that there is about an eight inch tail coming out of the antenna, the rest of the length (~15 feet) extending to the connector to the receiver. I decided to pull the antenna wire down the tower tubes, from the top, so that the (smaller) receiver connector would travel through the tower tube, rather than the larger bayonet connector.
I pulled out both the left and right speaker wires, tying a single line of braided cord to one, and a loop of braided nylon cord to the other so I would have three lines to pull not only both speaker wires back up the tower tube but also the antenna wire on the extra cord (and again, down the tower tube).
I used a lot of thread lock on both the bayonet connector and two piece threaded stem of the antenna. The stem is two sections of threaded stainless tube, one is fixed into the antenna, and the other is an outer sleeve with internal thread for threading onto fixed stem (in order to adjust length) and external thread for accepting the nut. Both sections have a longitudinal slot which, when lined up between both sections, allows you to pull the wire out between the antenna and nut. That way, the wire can be extended into the core of a hollow tube, with the antenna capping the top of the through-hole and the nut the bottom. I re-used all the original (neoprene?) grommets. I carefully) sliced off the shrink tube around the speaker wires at the tower's pivot bracket and replaced it with three sections of fresh shrink tube.
This shows the port, fore-to-aft cross bar between the rear (shown) and front (not in view) tower tubes of a flight control tower. The antenna is in the foreground.
Here you see the same except with a wider (and deeper in field) view.
This shows the bottom of the port, fore-to-aft cross bar. You can see the nut for securing the antenna on this (bottom) side of the cross bar. This took a good sized hole, but I was able to do it with countersinks. Note the shallow angle hole in the cross bar aimed at what is the front tower tube (when the tower is folded up). That is how I opened a hole between the core of the cross bar and the core of the front tower tube (this hole is not shown) though which to extend the antenna wire. I could not get a grommet in there, so I protected the wire with shrink tube.
To drill that shallow angle hole, for a drill guide, I used a Sears pocket hole jig ($40). I had to cut off its last two flanges, so the jig is destroyed for its intended purpose (I guess)