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[TowerTalk] Mosley matching systems

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Subject: [TowerTalk] Mosley matching systems
From: (Pete Smith)
Date: Fri, 12 Nov 1999 17:54:36 +0000
At 11:05 AM 11/12/99 EST, N4CW wrote:
>My old TA-36 (vintage unknown, but precedes the "Classic" series) has a 
>unique feed. The trapped driven element is insulated and fed at the center
>a balanced fashion. However, the coax from the station goes to a tee at the 
>antenna, and each side of the tee connects to a 47" length of RG-8. At the 
>far end of the coax, you strip back the outer jacket for 3 5/8", undo the 
>braid from both pieces, twisting them together and solder on a solder lug. 
>The center conductors are stripped back 1/2", twisted together and a solder 
>lug is soldered to those. Each solder lug is connected to the feed points of 
>the driven element.
>I have no idea how the transformation from a balanced antenna to an 
>unbalanced feed line takes place with this configuration. But it does work, 
>albeit nowhere as good as other antennas I've had.

Sounds like a lossy T-match, using the capacitance of the RG-8.  I don't
see how there can be a transformation to unbalanced taking place in a
symmetrical feed system, so if it were me I'd put a bead balun at the

We had a CL-36 at the State Department ham club that was fed by a length of
coax lying inside one side of the driven element, not electrically
connected to anything.  Dunno if that was standard.  It, too, worked OK -

73, Pete Smith N4ZR 

Sometimes a tower is just a tower

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