[Antennas] TOP V. BASE FEED

Wed, 9 Oct 2002 05:21:42 -0400

Agreed. Top loading very effective & standard. Top hat can't be to large on
base fed or pattern disturbed.
Top fed antenna better in many circumstances.
----- Original Message -----
From: alexander eban <[email protected]>
To: <[email protected]>; W2WU <[email protected]>
Cc: <[email protected]>; <[email protected]>
Sent: 09 October, 2002 04:56
Subject: RE: [Antennas] Re: Elevated Ground Plane Question


> ...this is NOT top loading. A few years back MFJ put out what was called
at
> the time ;Top Fed Antenna. The rationale behind it was that since the
energy
> goes out at a slent angle from the radials and/or grounplane, feeding the
> antenna at the top and moving the ground plane at the top would result in
> radiation parallel to the ground. Actually it was shot into the ground!
That
> antenna was never  popular, probably because a lot of guys figured out
> something's fishy. The only good thing of that antenna was the size. I
> wouldn't recommend it, certainly not as a main antenna!
> 73 and all the best
> Alex 4Z5KS.
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> Sent: Wednesday, October 09, 2002 5:07 AM
> To: W2WU
> Cc: [email protected]; [email protected]
> Subject: [Antennas] Re: Elevated Ground Plane Question
>
>
> Top loading is the most efficient form of loading a shortened vertical!
> That's true in broadcast or amateur circles :)
>
> But of course the question here does not concern the vertical
> radiator but the ground radials...and they should be kept out of the way
of
> the vertical element....
>
> Chris
> WB5ITT
>
> W2WU wrote:
> >
> > A small "top hat" on a vertical is an old broadcast antenna trick. I
> > agree that putting radial on top of the antenna would severely limit
> > current flow and proper radiation.
> >
> > In fact a large hat would cancel proper radiation. See: Dr. Brown &
> > his paper on vertical antennas. Also see "Antenna Engineering
> > Handbook" by Jasik, John Battonson B.E. & other applicable engineering
> > texts.
> - - -
>
> Your moderator for this list is:
> Larry Wilson KE1HZ [email protected]
> _______________________________________________
> Antennas mailing list
> [email protected] http://mailman.qth.net/mailman/listinfo/antennas
>
> ---
> Incoming mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.394 / Virus Database: 224 - Release Date: 03/10/02
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.394 / Virus Database: 224 - Release Date: 03/10/02
>