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Old June 24th 05, 10:40 PM
Walter Maxwell
 
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"Dave Platt" wrote in message
...
Greetings

A gentleman on another group.. is telling me that he wants to put up an
offset dipole antenna and feed it with a balum.. He is a new amateur and I
can tell he does't have much antenna knowledge...

He is being advise to use an offset antenna wich in my mind isn't the best
answer to his problem....


That may depend to some extent on what his problem is grin

Does anyone know of a website that describes the offset antenna better than
I can....


http://www.cebik.com/gup/gup9.html seems a good place to start.

--
Dave Platt AE6EO


Larry, what do you mean by 'offset'? Do you really mean 'off-center fed'? If
that's the case the only reason one would want to feed an antenna off center
would be if it permitted a better chance for a 90° angle between the antenna and
the feedline from where the feedline enters the house.

A dipole is a dipole, no matter how it's fed, center, off center, or end. The
only difference in the radiation pattern between the various methods of feeding
is the re-radiation effect of the feeder if it's not in a neutral portion of the
radiation from the dipole, causing current to flow on the feeder and thus
radiating in addition to that of the dipole.

The dipole fed at the center with the feedline coming away from the dipole at
90°, the feedline will not be a part of the radiator, unless the feedline is
coax with no balun. The balun prevents antenna currents from flowing on the
outside of the coax shield, thus preventing radiation fromthe feedline.

Incidentally, the spelling is baluN, not baluM, the term coming from the
combination of two words, BALance to UNbalance.

Walt, W2DU