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Old August 9th 03, 01:35 AM
 
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Tis possible-- reason the ground radials / extra piece of coax was there is
because the *(^$%( antenna was poorly designed- didn't decouple the coax
from the antenna. Now what did this have to do with the price of tea in
China? well, when AEA created the iso-pole, (really a 1/2 wave coaxial
antenna, decoupled with 2- 1/4 wavelength cones), and the antenna , down to
the end of the first cone (if memory serves me correct) radiated, giving it
, it's stated gain. NO RADIATION FROM THE COAX RESULTED (or very little), to
distort the verticle patern.
This was demonstrated at a ARRL convention many years ago, in side by side
demo, with the CUSHCRAFT. a sampleing loop next to the coax on the ISOPOLE
showed NO RADIATION, while the CUSHCRAFT lit a #43 lamp to almost full
brilliance (both these on a loop held next to the coax, about 10 feet down
the run.) That EXTRA PIECE OF COAX/GROUND RADIALS was cushcrafts answer to
eliminate that radiation (and by corolary, recieve distortion) of the
antenna pattern! In other words, without it, your coax is radiating (and
also acting as a recieve antenna. If you want the TRUE antenna pattern, put
those pieces back on -the one busted radial probably doesnt make that much
diff, but as a whole, without it will distort the antenna pattern. As
info, Jim NN7K




Andy sent: Hello all. I recently bought an Icom IC-38A and a Cushcraft
Ringo II ARX-220B
antenna. When the previous owner was taking down the antenna, he

accidentally
snapped one of the radials at the thread. I put the antenna up without the
extra piece of coax and the radials and the SWR is just fine. I can even

hear a
repeater about 50 miles north of me with the antenna only 10 feet off of

the
ground.

Will I benefit by having the radials? I was thinking of contacting

Cushcraft to
see what replacement radials would cost.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
73! de Andy KC2SSB (ex: KF4KHC/HL9HCT)