[Antennas] Hairpin Monopole

Tue, 6 May 2003 13:09:39 -0400

----- Original Message ----- 
From: "Juan A. Bertolin (EA5XQ)" <[email protected]>
To: <[email protected]>
Sent: Tuesday, May 06, 2003 10:06 AM
Subject: [Antennas] Hairpin Monopole

Hi to all,

Recently, looking into Internet for information about indoor antennas and
antennas for reduced spaces I found the Hairpin Monopole article written by
Wilfred Caron. It seems very interesting antenna, is there other places
where I could find more information about this monopole?(I do not see clear
the pictures and explanation of Mr. Caron) Any experience of some of you
with this antenna?

I'm interested in using it for 20,40 and 80m...
_______________________________________________________________
Dear Juan,

I have built a full size 40 meter version of the quarter wave folded
vertical. I used a 35 ft. length of ladder line as the radiating element and
suspended it from a tree. It gave a high real (resistive) component to the
feed point impedance, as one would expect, and was easy to tune with a
standard C-L-C tuner at its base. So far as performance is concerned, it has
a low take-off angle by virtue of its intrinsic characteristics and a high
efficiency without an extensive ground plane. I used the chain link fence
around the yard as my earth connection. My only complaint about this type of
antenna for amateur work is the same complaint that I have about all
verticals in comparison with Herzian antennas - they just don't measure up
in simple A/B switch tests in real QSO's
.
You may be interested to know that Mr. Caron was the author of the ARRL
book, "Antenna Impedance Matching". I used his book in preparing the
extensive Help file for my Smith Chart program, which can be found at my Web
site. The help file is based almost entirely on Mr. Caron's book.

I would not recommend this type of antenna for multi-band use unless you
have a remotely controlled tuner at the base of the antenna or are not
concerned about the high SWR values that would be encountered on the feed
line.

73 de W9DMK (Bob Lay in Dahlgren, VA
http://www.qsl.net/w9dmk