[Elecraft] The use of a doublet

[Phil LaMarche]

DX Engineering shared an antenna with me that I put up and it works
wonderful on all  bands with a tuner.  120 ft and fed with 90 ft of 300 ohm
line into a 1:1 balun of theirs and into the tuner with RE 213.  Tuner is a
Palstar AT2K.  The feed line length must be 90 feet.  YES, it really works.

Phil 


Philip LaMarche 
LaMarche Enterprises, Inc.
www.instantgourmetspices.com

www.w9dvm.com 
800-395-7795 pin 02 
727-944-3226 
FAX 727-937-8834 
NASFT 30210 

K3  #1605

CCA 98  00827
CRA 1701

W9DVM 



-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of dw
Sent: Tuesday, July 14, 2009 12:26 PM
To: Elecraft_List
Subject: [Elecraft] The use of a doublet

Great post Rick!

Yes, the doublet has been over the years for me the easiest and best
performing all band single antenna I've ever had.
I feed mine with 450 also, but the top is only 135' long.
I use the more robust SGC auto-tuner in external config.
40 feet of good quality coax and a high quality balun feed the tuner.
With 20 watts applied, it finds best match in 3 seconds.
It makes me feel like I'm cheating!!  ;^D

Duane
N1BBR 

Hello Jim,
  I saw two of those tape measures once and they were actually part of a
military dipole antenna system.  The original antenna had 2 of them and you
just pulled them ou to the coresponding frequency measurements on each side
and you had a resonant dipole for that frequency.  So if your friend used
that to measue the wire with, then its most likely somewhere around 33 feet
on each side.  Being fed with 300 ohm balanced feedline makes your antenna a
doublet - and a doublet is a very good all band antenna !  I use a doublet
here that is 178 feet long - 89 feet per side and fed with 450 ohm feedline
and it works 10 thru 160 meters via the tuner.

73 - Rick McKee, KC8AON
Southern Ohio - EM88sn
www.angelfire.com/electronic2/qrp
With God all things are possible ~ ><(('> ~
--
 Bw_dw at fastmail.net

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