I have a 91XG mounted at the very top of a mast in such a way that the antenna boom is about 6" above the top of the mast. The antenna has a bottom support that is attached to the mast while the actual boom sits higher.

I am considering installing another antenna and would like to move the 91XG about 8" lower on the mast. By doing this, the mast will contact the main boom and run about 2" above it. On top of the mast I will then mount a Fanfare FM-2G 1/2 wavelength FM whip antenna.

Will this interfere with the performance of the 91XG? My main concern is the 1-1/2" mast which will travel right through the middle of the antenna. In your opinions, would mounting an XG91 mid-mast instead of at the top cause interference or loss of gain?

This would not seem to be a probelm with VHF antennas with longer elements, but UHF antennas have fairly narrow elements.

Bill

It won't matter to any measurable degree. Mine is mounted as you have proposed but with a Wilson cellular yagi about 4-5 feet above it on a 10' mast. I noticed no difference in signal strength when I went from a 5' mast with only the 91XG on it to the longer mast with the little antenna on top.