[TowerTalk] half wave verticals

Ron Youvan ka4inm@qsl.net
Mon, 11 Oct 1999 19:13:01 +0000


thompson@mindspring.com wrote:

> << There have been several messages on a half wave verticals not needing
> radials.  Any vertical works better with radials.  >>

  I disagree!  Quarter wave antennae  REQUIRE a counterpoise' to produce an
equal but opposite `image' of the elementto be an ANTENNA.  Two quarter WL
antennae stacked with the feed points together produced a dipole   A pipe in
the ground is not a counterpoise, because of the high resistance of the
dirt.  (salt water excepted)
    37 + 37 = 72 OHMS

  A vertical half wave element (which can be feed at either end with proper
matching, if you wish) can be elevated any amount you wish ,  if over the
houses and trees this will reduce the effects of the ground clutter, is
unsurpassed.  IMHO

> << A vertical dipole will work OK with center feed, but feeding at the base
>
> with radials attached will work even better.  >>

  If you don't match the 5 k or so input impedance it won't.  Radials do
little, to a dipole, but change the radiation angle, and possibly detune it
comparing it to it's `mounted high away from everything frequency.'

  73 (= Best Regards) de: Ron ka4inm@qsl.net
VISIT my HAM WEB SITE at: http://www.qsl.net/ka4inm
  using LINUX here & loving it!




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