Richard Clark wrote:
On Mon, 4 Sep 2006 15:23:37 -0400, "Jimmie D"
wrote:

I heard once upon a time that the Ringo utilizes
the mast as part of the radiator.

Hi Jimmie,

What was meant was that the mast inappropriately became part of the
radiator due to the design of the Ringo (which has had a reputation
for being a dummy load). The problem with half-wave designs is they
are high Z. Being high Z they are difficult to choke. Being
difficult to choke, they appropriate masts, supports, feed lines, as
additional radiation surfaces. When you add these lengths to the
radiator (and they are co-linear) then your radiation lobes begin to
climb into the sky (no one there to hear you) and the antenna becomes
deaf and dumb.

It's probably more critical on VHF/UHF, but on the HF bands I never
had any trouble with ringos and decoupling problems overly skewing
the pattern. I've used a few with no decoupling at all, and they
worked
fine. But I'm of the opinion that the "gamma loop" type feed helps
decouple the feedline a bit better than some other methods of feeding.
I tried adding a decoupling section to one I used on 10m a few years
ago, and it did help, but not in a huge amount. I found the antennas
pretty easy to choke by using a 1/4 WL section of coax, and then 4
radials.
Much the same as used on the "ringo ranger" antennas. Anyway, I've
never seen a case on HF where I thought a ringo acted like a dummy
load.
I imagine it's possible on VHF though, if precautions aren't taken.
I've used lots of them on 10m at various heights. Always worked pretty
well. And I never noticed an overly hot feedline.
The only times I had horrible results with a half wave was a time years
ago when
I tried to make a center fed job, using peeled back coax braid as part
of the
antenna. The decoupling from the line was horrible on that thing.
That was on VHF though where the problem shows up more.
MK

..
The only times I had horrible results with a half wave was a time years
ago when
I tried to make a center fed job, using peeled back coax braid as part
of the
antenna. The decoupling from the line was horrible on that thing.
That was on VHF though where the problem shows up more.
MK


Ive had trouble with this type of antenna too. Turning the shield inside out
over the feedline is not a good idea. The outer viynl jacket has some very
poor RF characteristics not to mention it is a bear to do. Stangely enough
plans for this antenna abound. Shakespeare used to build a CB antenna lie
this called the big stick They latter change it to four wires inside a
fibergas tube with th wires imbedded in the fiberglass connected to the
shield of the feedline. Then the feedline is centered in the tube using
styrofoam. I built something similar using a metal tube connecting to the
shield with the coax down the middle of the tube also using little pieces of
styrofam to center the cable in the tube. This seemed to work pretty good.