Kevin (and others) What the deal is- that the original ARX-2 (not
De-coupled) allows rf to go on the outside sheath of the coax, allowing
it to become part of the antenna system. The decoupleing stub- with
1/4 wave ground plane radials, forces the rf off the coax below
the radials, allowing 2 features- 1) minimizes rf feedback towards the
rig (eliminates rf burns, in high power, and 2) makes the antenna
radiate simetrically (when the coax shield radiates, it distorts the
antenna pattern, both in recieve, and transmit.) Realistically, it
probably makes little difference, overall, but was a sales pitch,
started by AEA, on its Isopole antenna. Was demonstrated at Seattle
ARRL convention side by side- The coax from the (original) ARX-2
would light a lamp on a RF sniffer, held next to the coax-- the ISOPOLE
didn't! Cushcrafts response was the ARX-2B (and a mod kit for the
ARX-2), that eliminated this coax radiation! You can easily duplicate
the effect with 3- 19 inch pieces of aluminium wire, to the mast , held
on with a hose clamp! (dont forget to also attach that coax shield, at
that point! ) Jim NN7K


...
I bought one of these at a hamfest from a SK's estate and thought it was a
ARX-2 and then noticed the 52" coax harness attached to it and realized
that it was probably a ARX-2B which seems to be the same except for the 3
radials which I guess didn't get sent to the hamfest.

Reviews of these 2 antennas seem to almost use the 2 model numbers
interchangeably so the question is... Is it worth making up a radial
system and taking another 5 feet of mast to re-manufacture this thing
into a ARX-2B?

What would be the advantage? Maybe somebody's used both.

Thanks,- I was sure somebody out there knew this

Kevin VE9-XYZ

On Sep 23, 4:16 pm, Jim-NN7K . wrote:
Realistically, it
probably makes little difference, overall, but was a sales pitch,
started by AEA, on its Isopole antenna.

I saw a large difference when I tested mine. Using stable local
signals to test, I often saw 3-4 S units worth of difference on
the old IC-22u I was using at that time.
But the difference will vary to each installation, length of coax,
etc... It's even possible for the common mode currents to add
in phase and cause an increased gain, but that is very rare.
The decoupling kit makes the antenna work the same no
matter the length of coax, etc..
Well worth the trouble I think.
BTW, I've compared the decoupled cushcraft to the isopole.
The decoupled cushcraft was close, much closer than the
non decoupled version, but the isopole was still the best
by a slight margin. The isopole was probably the best dual
5/8 antenna ever made as far as decoupling the line.
But for the money and slimmer looks, the 2B cushcraft is
pretty good. I used one for a long time.
MK

On Sun, 23 Sep 2007 15:06:19 -0700, nm5k wrote:

BTW, I've compared the decoupled cushcraft to the isopole. The decoupled
cushcraft was close, much closer than the non decoupled version, but the
isopole was still the best by a slight margin. The isopole was probably
the best dual 5/8 antenna ever made as far as decoupling the line. But
for the money and slimmer looks, the 2B cushcraft is pretty good. I used
one for a long time. MK

Speaking of Isopoles, apparently the outfit that bought the Isopole
segment of AEA has never brought them to market. Fair enough. However,
there is an outfit called Spectral (from Brazil, I believe) that is
selling an "Isopole" that looks all the world in their ads the same as an
AEA model. Their pricing is rather steep compared to when AEA was still
a going concern. Has anyone tried one?

Fortunately, I still have most of a new 2m Isopole in a box that I picked
up at a hamfest a few years back.

73, de Nate

--

"The optimist proclaims that we live in the best of all possible worlds,
the pessimist fears this is true."