On Sun, 24 Apr 2005 15:12:26 -0700, Roy Lewallen
wrote:

I presume you realize that a 3/2 wave dipole has multiple lobes, with
nulls between. At many or most angles, a half wavelength dipole has
greater gain.

Yes, I believe it has four major lobes and a few minor lobes as well.
None are exactly perpendicular to the wire (IIRC).


You can get just two narrow lobes from a 3/2 wave dipole by rotating the
wires 30 degrees to form a horizontal "V" having a 120 degree included
angle. I've used this trick with a 40 meter dipole being used on 15
meters -- it doesn't have much effect on the 40 meter pattern. (You'll
see some TV antennas made this way for the same reason -- the high TV
channels are about 3 times the frequency of the low channels.)

You got me on this one. I haven't looked into the 'V-Beams'. I was
thinking they were 1/2 wave dipoles. TV antennas are also a form or
Log-Periodic aren't they?

But
again, if a station isn't in the right direction, you'll do better with
a half wave dipole than a 3/2 wave one.
A "gain" antenna isn't of much use if the gain is in the wrong
directions. In fact, it's worse than a lower gain one, since the higher
gain it gets in a few directions comes at the expense of lower gain in
the remainder.


Yes, this is a form of compromise antenna. I guess if I were looking
for the perfect (omni) antenna, it would be a loop.

Many hams use G5RVs or tuned dipoles cut for their lowest desired
band. While they all work, they all have their lobes on certain
bands, probably each band with different lobes.

I realize that the antenna will have nulls and lobes. If possible, I
would want to arrange the antenna in such a way as to use the lobes to
my benefit. Primarily, it is an experimental antenna as much for the
fun of building it as for using it.

I also plan to build a multi-band beam, but not right away.

Thanks for the input. I'll check into the 'V' antenna.


Roy Lewallen, W7EL


--
73 for now
Buck
N4PGW