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Does a j pole need grounding and/or a balun?
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January 7th 05, 03:07 PM
Eike Lantzsch, ZP6CGE
Posts: n/a
wrote:
I have been reading alot on different designs and have read
contradictory information on this. Does nayone here have an opinion?
As I understand it, a J-pole is derived from nothing but an inverted
Zeppelin-antenna. That makes the feedpoint a balanced one and you
need a balun or at least a choke. But as a Zepp-antenna it does not
need any ground just like ordinary dipoles don't. But if you ground
a J-pole the ground needs to be exactly in the middle of the short
in the feed line. For practical reasons most J-poles are not
constructed this way.
Also, when building a j-pole, could I run the wire inside the tube.
(Regular jacketed copper wire) to the bottom of the tube to a pl
connector? Or would this mess up the impedance?
What you are looking for is on YO5OFH, Csaba Gajdos web page he
http://www.qsl.net/yo5ofh/projects/a...ol_antenna.htm
but I didn't try the design myself yet. I might within short.
There is ample of information on J-poles he
http://www.cebik.com/jp1.html
Kind regards, Eike
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