On Thu, 28 May 2009 11:15:52 -0400, Bob D. wrote:

I decided to install a 2m FM rig in my garage to stay in touch with the
local repeaters while working on the car. I want a quick and dirty
homebrew antenna at the roof line. I know the J-pole is a popular 2m
antenna, but why??? The J-pole is basically a half wave antenna fed at
the end, right? At 2m you are only 19 inches away from the 50 ohm feed
point (a classic dipole), so why not just loop the coax into the middle
and forget the matching stub? Am I missing something?

If I do this, would a clip on ferrite at the feed point make a good
choke-balun?

There's not much performance difference between a J-pole, vertical
dipole, and a quarter-wave ground-plane vertical for working "local"
repeaters.

A J-pole for outdoor use can be easy to build, easy to mount, and very
rugged. For indoor use, you might want to settle for a simple twin-lead
J-pole, which is even easier to build and can be easy to mount.

A vertical dipole will tend to have a screwy radiation pattern if you
just run the coax up from below and connect to the middle. But probably
not enough for you to care.

I'd go with whatever seems easiest to make and easiest to mount in your
particular situation.

.... Rich W2RG