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Balun for Doublet Antenna

Mar 4th, 17:26

N8EUI

Joined: Jul 15th 2010, 16:49
Total Topics: 0
Total Posts: 0
Hello,
I'm building a 40-10 meter doublet for summer field day. I will be feeding it with 450 ohm window line. My antenna tuner only accepts unbalanced feedlines, so I will need a coax to twin lead balun to transition from the 50 ohm tuner to the 450 ohm feed line. My question is what ratio of balun should I use? Conventional wisdom would say a 9:1 balun. Is this correct? Also, should a current or voltage balun be used in this antenna design?

Thank you,
Tom, N8EUI
Mar 5th, 11:08

W1VT

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
http://www.karinya.net/g3txq/tuner_balun/
study of the best balun to use

A 130 ft center fed dipole fed with 100 feet of 450 ohm window line and a 1:1 current balun is one of the better known combinations.

W5DXP has a downloadable spreadsheet if you would like to know good combinations of dipole and ladder line length for different bands.

http://www.w5dxp.com/goodbad/goodbad.htm

Zak W1VT
ARRL Senior Lab Engineer
Mar 6th, 19:43

N8EUI

Joined: Jul 15th 2010, 16:49
Total Topics: 0
Total Posts: 0
Thanks, W1VT for the reply and info.

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