Here's why some of the TV antenna elements are V shaped, and you can
verify this with your EZNEC in a couple of minutes:

Take a 40 meter dipole and excite it on 15 meters. You'll find you get a
cloverleaf pattern. Now bend each of the arms 30 degrees to form a vee
with 120 degree included angle. You'll see that the lobes in the
cloverleaf now line up to make a bidirectional pattern. The pattern on
40 meters isn't changed much by this modification. So you can make an
effective 40/15 meter bidirectional antenna using this technique. (I've
done it. Works great -- as long as the stations you want to talk to are
in line with the lobes.)

The upper TV channels are approximately three times the frequency of the
lower ones, just like 40 and 15 meters. So the same trick is used for TV
antennas, making some elements do double duty.

This is, by the way, the principle behind the vee beam. As you make the
dipole longer and longer, the lobes point more and more away from the
center and toward the end. So you have to bend the antenna at more and
more of an angle to get them to line up. This is where the graph showing
optimum angle vs vee beam leg length comes from.

Roy Lewallen, W7EL

AndyS wrote:
Andy writes;

I know I could go to my EZNEC and find this out for myself,
but I figure someone here has already done this and a quick
answer is all I need..

In "normal" Yagi antennae, the elements are parallel
and at 90 degrees to the mounting boom.

In some TV antennae, the elements are at an angle to the
mounting boom, slanted in the direction of the station being
received. Otherwise, they look pretty much like a Yagi.

My question is, what effect does "slanting" the elements
forward have on the impedance, and the pattern ?

[ [ [ [ [ [

Normal Yagi Slanted Yagi


Thanks in advance for the meaningful answers..

Andy W4OAH