I am mounting a hex-beam antenna to the peak of my house (assuming that I can find someone with a cherry-picker or a scissor-lift that can help me get it up there). Right at that end of the house is an open vent into my attic, which is easily accessible. In addition to reinforcing the mounting location with 2x4s, I am wondering if I should run the coax from the antenna into the vent, and from there through the wall down into my basement. Back about 6 years ago, my first antenna was fed that way, but this was a G5RV with ladder line; this caused a lot of RF interference in other devices in the house, and I got a lot on receive also (for those who don't know, the feed-line for a G5RV antenna is ladder-line - window-line? - and is a radiating part of the antenna).
In the current case, routing coax inside the walls would be about half the coax length required if I were to route it around the house outside and then through the bulkhead fitting I have in my basement door. But can I expect inferior performance due to send/receive interference? Assuming no common-mode on the coax, is this a reasonable solution?