It's an autotransformer.
T200-2 core works good.
3 or 4 turn primary, 29 or so turns on secondary.
Tie the cold ends of the windings together and they go to the coax shield
and ground or to a very short counterpoise wire, say 3 or 4 feet. You can
tweak it on frequency with the short wire.
The end of the big winding goes to the half wave end fed wire.
Simple stuff.
I have a QRP version that uses a T50-2 and a QRO version that uses the
T200-2, but T400-2 cores are available for those who want QROOOO. ;>)
Mike Baker K7DD
K7dd@cox.net
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of ronald long
Sent: Saturday, March 10, 2012 9:11 AM
To: TowerTalk
Subject: [TowerTalk] Radiowavz end fed wire antenna
I wonder if anyone has cut open the matching gizmo on a Radiowavz end fed
wire antenna, such as the EF-40 or has any information on its design.
http://www.radiowavz.com/html/end_fed_h_w.html
What I call the matching gizmo has only one terminal so IMHO it cannot be a
balun. Could it obtain low VSWR by means of a resistor (loss)?
ron long w8gus
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