I want to install the new Yaesu FT-8900 in my truck in the near future. It features 10m, 6m, 2m, and 70cm operation and should be a blast in the truck. I perfer NMO mount antennas and usually punch a 3/4&quot; hole just above the dome light for a clean permanent mount. I have a Leer fiberglass cap on this one, and would like to install individual 10M, 6M, and 2m/70cm antennas centered on the cap. The first question though is how to create a ground plane under the array, and second, how do I mount them?<br><br>I was thinking of bending up a large narrow bracket that would stand off the roof of the cap slightly and would provide a counterpoise too. My 3 antennas would be mounted inline. I would prefer direct mount to the cap though. Any ideas?<br><br>-Tom, K3GM-

 

The 2m is easy, just put a couple of 19&quot; wires under for a counterpose. The longer ones are not so easy, can you run a wire down each side grounded to the pu body? Or maybe a sheet metal or screen ceiling in the thing. All you can do is experiment, they will not load to normal standards mounted on glass. How about a marine antenna? They are built for that. I know that they make 10 in a groundless antenna which is basically a loaded verticle dipole fed from the bottom, like a cb bigstick, a coaxal antenna but loaded for a shorter length. I know the cure, but don't know if you want to get the crafty. Build a J pole, they work great, but it would be quite high. You can use a cb whip cut off and make an insulated base to hold the tuning section. I ran a home mede J pole on a big truck, it just looked like a cb. Oh well, just some ideas. Oh yeah, I run a full length cb shakspere whip mounted at the bottom of the rear window level and have no problems with heigth. A 10 on the roof would probably be about the same maybe a little higher. Another thing you can do is put any length whip up and feed it through a tuner. It will work as a random wire and let you load other freq. I did that a lot on the big trucks. Want to get fancy, run a loop a foot or so above the roof and feed it through a tuner, or the loop is not far off, just tune it, they are vertically polorized.

 

Thanks, Haulin', you offered some good ideas. You're the second person to suggest the screen on the ceiling, so I might give that a try, connecting everything to the body of the truck in several places. What I have in mind is 3 Larsen whips. A base loaded 10, a 1/4 w for 6, and a 5/8 over a 1/2 w for 2 and 70cm. They all should look pretty uniform an won't stick out too badly. Let you know how I make out.

 

Hey I knew a guy that did this... Insulate your hitch on teflon, put some inductance in line with all of the pigtail wires and use a tuner to load up the trailer You have a random dipole that is loaded against the truck. What I ran for several years with the big truck, was TR7, Dentron Supertuner, and 45 feet of wire over a flatbed. I had a post over the headache rack and attached a fishing pole with copper antenna wire out to a side kit post at the rear of the trailer. The wire was at 13 foot and loaded on any frequency. It did as good as a dipole at the house. My scanner is down so I can't send a picture but I have a couple.