Visitor:
When I first installed my CB radio, I made use of a matching transformer to allow sharing of the AM/FM antenna with the CB. While this worked reasonably well it had some drawbacks. First, it was not a very good antenna, and being mounted close to the engine, picked up lots of noise. Then it also required the antenna to be extended for use which is not a good idea when overhanging branches threaten to tear it off. So, I pickeup up a 4' FireStik-II antenna and decided to mount it on the rear tire carrier frame. When installed on my rear tire rack, I had the antenna tuned (to 1.2 SWR) and it worked fine. After a few months my transmit quality was down and I assumed the radio was going out on me). My antenna had a decent ground (at DC) but at RF, I think it was more like an open. My SWR was over 3, adding a heavy ground conductor only brought it into the high 2's.
To digress a bit into RF signal propogation theory, what an antenna really likes to see is a conductive plane at ground potential (a ground plane) stretching off to infinity below it in all directions. My 4Runner isn't quite that big, but my tire carrier rack is even smaller. The largest expanse of relatively horizonal metal in the 4Runner is the body, so by mounting the antenna in contact with the body is the best solution. Since the shell on the 1st generation 4Runner is non-conductive fiberglass, this large surface is not useable as is.
Anyway, Scott Wilson has a nice setup for his '88 4Runner and I modified his design for my needs. Since I had the shell off for the summer, it was easy to do this installation.
Basically,
with the shell off, I sanded the paint off a section of the left rear
corner, outside the raised area where the shell gasket mounts to. I
used 1"x 1/8" steel bar stock, cut to length and riveted to
the body. I also inserted one 1/4" pan-head bolt for added
strength.
Cost:
$ ------------------------------ $100
Project Rating:
