Ringo Ranger ARX2 vs ARX2b
Chuck Forsberg WA7KGX N2469R
antenna. Is there much difference in performance between
the arx2b and the original arx2?
--
Chuck Forsberg c...@omen.com www.omen.com 503-614-0430
Developer of Industrial ZMODEM(Tm) for Embedded Applications
Omen Technology Inc "The High Reliability Software"
10255 NW Old Cornelius Pass Portland OR 97231 FAX 629-0665
gree...@neo.rr.com
<c...@omen.com> wrote:
>The B version has a piece of mast below the main part of the
>antenna. Is there much difference in performance between
>the arx2b and the original arx2?
It's been a long time, but I think the non-b version was criticized
for having a lot of RF on the feedline. That would distort the
radiation pattern somewhat. The b version corrected that.
Dave Platt
>antenna. Is there much difference in performance between
>the arx2b and the original arx2?
My understanding is that the lower section (with its radial stubs)
serves as a decoupling element, and greatly reduces the possibility of
RF current flow on the lower mast.
The original ARX2 seems to have a reputation for being somewhat
installation-sensitive. In some installations, enough RF can flow on
the mast and/or feedline to alter the antenna's radiation pattern...
the main lobe can "squint" away from the horizon and thus reduce the
useful gain of the antenna somewhat. In other installations (with
different mast and feedline lengths) this wasn't as much of a problem.
Adding the decoupling section to the design has (from what I've heard)
significantly reduced the problem, and allows the ARX2B to perform
more consistently than the ARX2 did.
Standard copper-pipe J-pole antennas (and similar designs) tend to
have the same issue - unless you decouple them from the mast and
feedline somehow (e.g. insulated mount, and a choke on the feedline)
their pattern can be installation-sensitive due to RF current flowing
where you don't want it.
--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
nm...@wt.net
wrote:
There is no extra mast. You are using the support mast
below the feed point. The extra parts are a 50 inch length
of coax, and a union to support a set of 20 inch long radials.
The radials are connected to the shield of the coax.
Years ago I converted an original Ringo Ranger to a
Ringo Ranger two using home brew parts.
I then did comparison tests with and without the radial
set. Made a huge difference in performance in my case.
Cushcraft seemed to consider it a third 5/8 WL element,
but I tend to consider it a decoupling section much
like the lower cone you see on an Isopole, or using
a 2nd set of radials or cones below a ground plane.
Yes, it is worth converting. The ARX2B is a pretty good
antenna. Not quite as good as the Isopole, but close.
JIMMIE
I have seen people swear by and swear at Ringo Rangers. Is this
because of by chance some people get the right/wrong length mast and/
or coax length?
Jimmie
nm...@wt.net
That could be the case with the non decoupled version. :/
But the RR2 is a pretty good antenna. I used one for a long
time and never had any problems.
The mast and coax length could be fairly critical on the
non decoupled version.
Like I said, I converted an old ARX2 to a ARX2B and then
compared the two when receiving local signals.
The difference in my particular case was quite large.
I'm talking 2-3+ S units on the radio meter which
actually would be a huge difference. It was quite
apparent that the common mode currents were really
whacking the pattern on the one I tried without the
decoupling section. I assume most was from the feed line.
Chuck Forsberg WA7KGX N2469R
what is the easiest/cheapest way to add the decoupling?
Just add some 1/4 wavelength radials 1/2 wavelength below
the arx2?
nm...@wt.net
wrote:
>
> what is the easiest/cheapest way to add the decoupling?
> Just add some 1/4 wavelength radials 1/2 wavelength below
> the arx2?
The factory version uses some kind of donut thing with
threaded holes for the radials. In my case, I just rigged
up a L plate of sorts that I drilled a hole for a coax union.
I used stiff wire radials that I bent into a short L at the end
and clamped them to the mast at that same plate.
The plate and radials naturally are grounded to the support
mast. You run a 50 inch length of coax from the feed point
down to the union on the radial/union plate. Adjust the
clamp so it's fairly taut. The radials are 20 inches long.
Not much to it. The trickiest part is making a union plate
and clamping it to the mast. Just use your imagination.
Not really critical as long as it's stays in place and grounds
to the mast. You can buy the threaded coax unions at
most of the radio parts stores. Maybe even rat shack.