A Discone with gain seemed like a good idea but seemingly impossible.
Then it occurred to me that you could add gain to a Discone by using a
reflector(s). My final idea is what I call a ''Parabolic Discone.''
It works by placing a Discone antenna at the focus of an extended
parabolic reflector. The parabolic section is focused straight up, and
a cone with a 45 degree reflecting angle is placed above the parabolic
section to direct the RF sideways again. The resulting ?pancake? field
is vertically polarized like the Discone.
I have tested the idea by building a ?slice? of the entire antenna.
Because I am paralyzed it was easier to test a slice of the antenna
than to try building a complete circular Parabolic Discone. The
principles and physics are the same. Testing at 1299 MHz showed that
the idea worked. (I actually transmitted on 433 MHz and used the 3rd
harmonic for reception on a ??police scanner??.)
The gain vs. size is similar to a traditional parabolic dish, except the
gain is focused sideways into a pancake field. You could steer the
field up or down by changing the angles of the overhead cone reflector.
It is also possible to substitute a dipole if you want narrower
bandwidth with gain.
You can see the details of my invention on my HamDomain.com website, at
the following link:
Michael Lake - KD8CIK
TowerTalk mailing list