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Choke Balun for 6 meter.

Sep 12th, 19:28

VE2GTN

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
I'm in the process of building a 6 meter dipole that will be installed in the attic. The feedline will be a combination of RG-213 and RG-8, about 40 feet long, total. I wish to build a choke balun with some length of RG-58 line on a 3 inch diameter PVC pipe in order to minimize RF coming back on the outer schield of the feedline. I've been searching all my ARRL reference books and could not find anything specific for the 6 meter band. Can anyone help ?

Thanks

Sep 13th, 13:15

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
http://www.eham.net/ehamforum/smf/index.php/topic,62734.0.html
WB2WIK suggests five turns on a 3" form.
But, 3" PVC pipe actually has a diameter of 3.5"

Zack W1VT
ARRL Senior Lab Engineer
Oct 21st, 02:38

N8CMQ

Joined: Feb 28th 2011, 01:24
Total Topics: 0
Total Posts: 0
At that frequency, snap on ferrite cores would work better than lossy RG-58 wound in a coil.
Or you could use regular toroids stacked on the coax to choke any antenna currents on the shield.
However, if you are coming away from the dipole in a straight line for a non-resonant length, you may not need the choke, as the amount of current should be low and not mess with the antenna pattern.
If the coax comes away and then parallels the antenna, then even a choke may not work in reducing the currents and pattern distortion. You would need several chokes at intervals that are non-resonant to eliminate the currents.
Nov 26th, 08:37

iz5xrc

Joined: Apr 30th, 14:10
Total Topics: 0
Total Posts: 0
I use a three turns, diameter 3.5", choke wound in the air.
It works fine on 6m with my single quad loop.

73s de Fabio, IZ5XRC

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