Originally Posted by Flybob
The junk Con CA_2500 fixed omni antenna uses a small hole (<1/2")in the roof only for the coax. There is no hole in the ceiling. The King Jack ( a much better antenna) requires a 2 1/2" hole in the roof and a smaller hole in the ceiling. Position is critical as you do not want to damage AC ducts or wiring in the roof.
Correct. On most installations, the Omni is on center line and the ceiling ducts are left and right of centerline. Of course, the installation of a Jack is not trivial, however, in replacing an Omni it appears to be straightforward.