Topband
[Top] [All Lists]

Re: Topband: Effect of current max not at base of vertical.

To: herbs@vitelcom.net
Subject: Re: Topband: Effect of current max not at base of vertical.
From: Guy Olinger K2AV <olinger@bellsouth.net>
Date: Fri, 23 Sep 2011 16:43:51 -0400
List-post: <topband@contesting.com">mailto:topband@contesting.com>
See http://www.fybush.com/sites/2005/site-051028.html

For 1530 kHz, that's a PAIR of two vertical halfwaves in phase.  50 kW
gives 3545.89 mV/m. Note the relative lack of neighbors, and therefore lack
of 24 hour miscellaneous diodic signal demodulation, talking window screens,
permanently lit florescent bulbs, etc.

Note that this monster is not too far from 160m.  Think big and put an only
slightly downsized 160 version out in the salt shallows somewhere on the
western side of Cheasapeake Bay. Without any controversy whatsoever as to
ground induction losses (zero) EZNEC says this would put 13.6 dbi gain
toward Europe at 3.1 degree takeoff. Order of magnitude: three element yagi.

Just for comparison, if I drain Chesapeake Bay and fill it with concrete
rubble and other urban debris (can do magical things in EZNEC) I get 5.0 dbi
at 12.9 degrees. The full table:

Urban debris:  5.0 @ 12.9d
Sandy          4.8 @ 10.7d
Rocky, poor    5.2 @ 10.6d




On Fri, Sep 23, 2011 at 1:21 AM, Herb Schoenbohm <herbs@vitelcom.net> wrote:

> George,  Are you familiar with the Franklyn antenna design?
> Some broadcasters swear by them and claim a 3 db increase over a 1/4
> vertical radiator.
>
_______________________________________________
UR RST IS ... ... ..9 QSB QSB - hw? BK

<Prev in Thread] Current Thread [Next in Thread>