I was looking a magnet where I can use 118-1ghz range. I know if you get a tri band gain is not all there. I am trying to not use more than 2 antennas. Any ideas what to look for?
There really isn't anything to listen to above the 900MHz LMR band, at least not anything your scanner will decode. 900MHz band is going to change, and while there will still be some stuff to listen to, a chunk of the spectrum is going to become an LTE type network.
I'd focus on the stuff below 900.
I haven't seen any good tri band antennas that have gain. Most them out there are either designed for multiband public safety radios where gain isn't as important, or for scanner listeners, where size/cost is usually the concern.
There may be some ham type antennas that may cover the 900MHz band, as well as VHF/UHF, but I've never really looked.
The Larsen NMO-150/450/800 is a good antenna, but doesn't have gain on VHF. It does have gain on UHF and higher (but not a lot). Using one of those, putting it in an ideal location and keeping the coax run short, or using higher grade coax is probably a good tactic.