[Towertalk] Feeding longwire with coax

[Chuck Counselman]

At 7:47 AM -0700 10/8/02, Steve Katz wrote:
>...Normally, for an end-fed wire, if the wire isn't brought directly 
>to the tuner, it's fed with open-wire or ladder line, using the 
>balanced output terminals of a tuner in the shack, and one side of 
>the line driving the wire, with the other side unterminated.  This 
>is the standard, old-fashioned "Zepp" feed, and it works.

Yes, it does.  The balanced line should be an odd number of quarter 
wavelengths long, and if the antenna and feedline are tuned 
correctly, the balanced line can be connected to an unbalanced tuner 
output without a balun, yet very little common-mode current flows at 
the tuner end.  If anyone is interested I can have a NEC-4 simulation 
of this that I could email.  I built it, too, and it worked.


>I wouldn't use coaxial cable for this, at least not for multi-band use.

Agreed.  The SWR on the line is very high.

73 de Chuck, W1HIS