Balanced-Line

KD7MW's  Antenna  Matchbox  Shoot-Out

On Real "Balanced-Line-Fed" Antennas

Myths and Legends die hard. 


Ask any old-timer (licensed 50+ years) what the best way is to feed an open-wire (balanced-line) fed antenna and they will roll their eyes, as if dreaming, and say the JOHNSON VIKING MATCHBOX.


Of course many people have never heard of the JV Matchbox; most have never seen one, and the commercial antenna matchbox OEMs would have us believe "their" matchbox is the best solution ever.


In this test of antenna matchboxes on real antennas fed with balanced-line (openwire) feedline, we will find out how the JV Matchbox fares against matchboxes using more modern technology.

The Rubber Hits the Road on REAL Antennas, not on Dummy Loads


Peter Klein (KD7MW) and I have had a strong interest in finding out how different antenna matchbox technologies perform together with Balanced-Line-Fed antennas.  My own field tests on OCFD antennas kept me too busy to perform tests on B-L-F antennas.  Luckily Peter found/made time to run several tests, testing 8 different matchboxes on 2 different antennas. 


We feel the results of Peter's test, albeit limited to just 2 antennas and 8 matchboxes, more realistically represent the true performance of each of the matchboxes tested.


As most of us know, the impedance presented to the antenna matchbox in the shack is determined by the characteristics of the antenna (i.e., the feedpoint impedance), as well as the characteristics and length of the feedline.  Therefore both antennas were tested with various feedline lengths, being sure to test both high and low impedances. 

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