A Mobile Antenna Mount for T-Hunting

A number of people have asked me about my mobile antenna setup for T-hunting. Rather than emailing a set of 25 or so pictures to each person who asks, I've decided to set up this web page in order to document the details.

Antenna & Mast:

My antenna is a classic "strung-wire" cubical quad antenna, the dimensions of which are available on many t-hunting web sites. Both the boom and the mast are made from 1" closet dowels. To attach the antenna to the mast, I took a 1/2" PVC "T" fitting, and cut the top section in half. The bottom of the PVC "T" fitting was then mated to the top of the mast.
The boom then fits into the top section of the "T" fitting. Hose clamps are used to hold everything together. For a handle, I again used a 1" closet dowel. I drilled a 1/4" hole about 2 inches deep into the end of the dowel, and then glued a 1/4" bolt inside of that.
I then lined the handle up with the antenna boom and drilled another 1/4" hole through the mast. After sliding the mast downward through the mount, a 1/4" nut holds the handle in place. For extra comfort, I added a piece of handle-grip foam from a bicycle shop.  


Antenna Mount

My car has a built-in roof rack and sunroof. The fore and aft support bars of the roof rack are adjustable. I adjusted them for maximum spacing between them. I used a piece of 2x6 pine for the main beam. I made it long enough to reach from the rear of the car to the middle of the sunroof. I then used two more pieces of 2x6 pine to support the main beam.
Although it's difficult to see, the underside of the support beams are actually curved to match the shape of the roof. The support beams are spaced far enough apart to fit just outside the adjustable roof rack arms. This prevents the mount from moving fore and aft.
The support beams are also exactly wide enough to fit snugly inside the roof rack. This prevents the mount from moving side-to-side. Gravity keeps the entire assembly from moving up and down. For the first few hunts, I lived with nothing more than a 1" hole at the front of the main beam. However, at freeway speeds, the mast was difficult to rotate, so I decided to add ball bearings.
These particular bearings are from an old transmission, but I imagine that they are also available at any auto parts store. They made quite a nice difference! For the base of the mast, I cut a piece of wood to fit inside the center armrest, and secured it to the sides of the armrest. While it may be tempting to secure the wooden base to the floor of the car, I speak from experience when I say that there may be sensitive electronics under there, so be careful!
While the base bearing looks similar to the one in the roof mount, it's actually one size smaller. The base of the mast was notched so that it would rest on the shoulders of the bearing, and not on the floor of the car. Obviously, the closer the mast is to perpendicular, the better, but this may not always be possible.
One final consideration that may be worth mentioning: I chose the length of the mast so that there was at least 1/4 wavelength between the bottom of the antenna and the top of the car. Happy Hunting!