As an experiment, I am thinking of converting my single wire inverted-U 160m
dipole into a folded dipole. I would really like to hear from anyone who
has made this change or used folded dipoles on 160m.
Looking back through the various books and magazines in my collection, my
curiosity has been pricked by those who have been brave to go to through the
mechanical difficulties of building such an antenna for the low bands with
assertions that folded dipoles seem to perform better than their single wire
counterparts. However, unfortunately, most of these seem to be subjective
comments, with no data to back them up.
With the small bandwidth available for CW DX operation on 160m, there seems
little to be gained in going to a folded antenna for gains in this area.
However, the chance to get rid of some I2R losses and use a closed circuit
antenna, with the consequent reduction in general noise and static build-up
seem attractive.
My intention is to feed the antenna with a 4:1 Guanella-type balun, as
described by Roy Lewallen W7EL in his The ARRL Antenna Compendium Vol. 1. (a
superior current type balun - Figure A3-4).
Any observations on the matter would be much appreciated.
Vy 73,
Steve, VK6VZ
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
|