Advice on antenna placement

[FullsizeJimmy]

I finally got my 2 meter radio and a 5/8 wave antenna. I'm trying to decide the best layout for my antennas. I have a 1990 Jimmy with the removable fiberglass half top. There is approximately 2'8" X 4'10" of steel roof. I currently have a cell phone antenna mounted about 8" from the back of the steel roof. Should I move the cell phone antenna forward and use that hole to mount my 2 meter antenna? The roof is definitely stiffer at that location, although I can address the rigidity of the sheet metal in other ways. The antenna might be slightly better protected at the back of the cab, but I don't know if having it at the back will adversely affect my transmission.

I also have a magnetic mount CB antenna that I need for some occasions. If I were to add a permanent mount CB antenna to the mix, should I try to find a different place to mount it other than the roof? I have always thought the mag mount worked well up there.

I'm not opposed to making new holes where I need to, but I'd like to try to do it right the first time, so I'm open to suggestions.

 

[angusdevil]

For the best possible ground plain on the roof, I would suggest having the antenna 19" away from any edges. This is best case scenario. I say if you don't have to make the hole any bigger from your cellphone antenna, install the 2m there and see how your SWR's look. If they look good, you can keep that hole occupied and place your cellphone antenna elsewhere.

You could also put your cb antenna up there but with them being such close proximity, you could run into some major issues of bleed or TX'in through the other antenna... OUCH. I say stick with the mag mount or try a mounting location off the rear bumper or spare tire rack (if you have one)

 

[mikelite80]

Having just passed my technician test this thread comes at a perfect time. I was planing on mounting my 2m antenna to my roof rack but was having second thoughts as I see most people mounting them to their hood or bumpers. So which is best? Also how much distance do you need to keep between a 2m and CB antenna? When I use it I just toss it on a mag mount and up on the roof.

Mike
KF7BMT
2001 4Runner