开云体育

Tony, I took a folded dipole, (one using coax) opened it up and put it
in a hula hoop. It works well for me, especially on radios that accept
75 ohm inputs. An impedance matcher allows good reception with 300 ohm
inputs as well. Here's the text of my message from this other group. The
tilt feature I incorporated helps too.
John

Here's an idea that I had that works well for me for FM. It is made of
coax cable so the impedance will be low to begin with, (whatever the
impedance of the cable is) RG-58a/u works for me. Anything will work as
long as it is not too big, (you'll see why) If You have a hula-hoop
handy, pull out the plug that splices it together. Install a half inch
PVC "T" on one end. Take 18-20 feet of the coax, (depending on how much
lead cable you need, about 9 feet will be in the loop). Bare back the
lead end of the cable so just a 1/4 inch of bare center conductor is
showing. Thread this end through the hula-hoop and tee until it just
protrudes out the other end. At this point, carefully bare a small area
of the coax shielding where it first entered the hula-hoop. Solder the
bared center conductor end back to the bared spot on the shield.
Incorporating the tee in this joint so that the lead in cable comes out
the center of the tee is the tricky part. Leave yourself enough cable to
work with when soldering and, if the coax is small gage, it will easily
go back in the hoop when the tee is made up. A little tape will make the
tee fitting snugger, the idea being that this antenna will TILT as will
as be directional. I've found this to be an important feature.
Flattening this arrangement down, (no hula-hoop) works well too. It, in
effect, becomes a coaxial folded dipole, (75ohm) If this is used with a
radio that takes a 300 ohm balanced input, just add a matcher, I
guarantee this will be worth the effort!