On Wed, 16 Mar 2005 12:51:17 GMT, "tom" wrote:

If you really needed to get a 2m rig on the air and you didn't have an swr
meter, do you think you could get way with creating a simple dipole if it
was VERY carefully cut according to the formula, and if you wound your own
impromptu balun out of 5-6, 4" diameter turns of the (RG-8)cable right below
the dipole? Even if the resonant frequency wasn't exactly in the middle of
the 2m band, how much damage to the rig would you be risking? I don't see
how it could do any serious damage, even if the swr was somehow slightly in
excess of 2, or is it just something that is never, ever done --- not
checking the swr first with a meter? According to the antenna books I'm
reading, 1/2 wave dipoles (where each radiating element is 1/4 wave) don't
need fancy matching transformation stuff, the only issue might be RF coming
back through the outer braid and causing the cable to radiate --- thus the
5-turns-on-the-cable balun.


First, remember that most local 2-meter activity is going to be
vertically polarized. That means the dipole would have to be held by
one end with the other end down. A very simple antenna for 2-meters
is the J-Pole. There are numerous sites giving the dimensions for one
made out of common TV twin-lead. You can also make one out of 1/2"
copper pipe soldered together. These are very simple antennas that
are inexpensive to build and will outperform the dipole you are
considering.

Dick - W6CCD