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Re: [TowerTalk] Dipole fed with balanced line?

To: Ken <>
Subject: Re: [TowerTalk] Dipole fed with balanced line?
From: Eddy Swynar <>
Date: Mon, 16 Jan 2012 08:56:33 -0500
List-post: <">>
On 2012-01-16, at 8:41 AM, Ken wrote:

> Actually this setup is covered in this month's QST "The Doctor Is In" column 
> with a couple of references to older QST articles.
> A center fed dipole with open wire or ladder line is a very good multi band 
> antenna if you have a tuner which will feed it.  A half wave at the lowest 
> frequency is the classic antenna and is covered in the Handbook and Antenna 
> Book.   Some people find that the high impedance of the full wave (e.g. 130' 
> on 40m) is difficult for some tuners to handle and a 100' length is a popular 
> size for 80m and up.   Myself, I prefer not to give up that extra length on 
> 80m.
> Antennas like this do not have to be precisely tuned.   135', 130', 125' all 
> will give essentially the same performance.   100' will give a slightly 
> reduced performance on 80m. 
> And additional plus of an antenna like this is that it will work very well on 
> the WARC bands like 60 and 30m. 
> I'm currently using an antenna like this.  40' of feedline to a 4:1 balun 
> outside the house, then coax directly to the Elecraft K3.  The K3's internal 
> tuner handles it perfectly on all the bands 80 through 6m. 

Hi Ken et al,

I had mis-givings here about feeding my 160-meter half-wave inverted "V" dipole 
(50' at the apex) with foam-type 300-ohm TV twin-lead---and using it on all 
bands from 160- to 10-meters---but my cares have been quickly laid to rest...

That sort of a multi-band tuned dipole is wonderful---and it even has the added 
bonus of some "long wire" gain on 80- through to 10-meters...this, despite the 
fact that it has good, round-the-compass coverage, what with the smaller, 
"fill-in" lobes radiated by the antenna, which increase in number the higher 
the frequency band.

One thing to pay attention to, though, is the feeder length: I settled upon one 
of the recommended lengths shown in my older small-sized ARRL ANTENNA HANDBOOK, 
otherwise I simply could not tune the thing on some bands with my transmatch...

~73~ de Eddy VE3CUI - VE3XZ


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