Message-ID: <001a01beed57$536ad300$af0861cb@Computer.earthlight.co.nz>
From: "Stan Andrews" <andrewss@earthlight.co.nz>
To: rsgb_lf_group@blacksheep.org
Subject: LF: Multiple Tuned Vertical
Date: Mon, 23 Aug 1999 23:03:51 +1200
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Hello All,
                 Was interested in the comments re the  M.T.V.    Some years
ago
came across a reference in  Technical  Topics,    RSGB.  Unfortunately
didn't
note  which  issue or  which    manual  .

           Did manage to find some data in  AMATEUR RADIO VERTICAL
ANTENNA  Handbook      by  Paul  H. LEE.      1974...   CQ Technical
Series.

Two types discussed.


A.     NORD   Antenna......    for  50  to   150    kc/s/...


Has a centre metal pole   with a gamma  type  matching  wire  from the top
of the
centre pole.  (No detail of the spacing,  wire dia   or centre pole  dia.
except that the bottom of centre pole is earthed.   From  the  top  of the
centre pole  there are three sloping  wires out to three    perimeter poles
each of which is earthed through a variable  condenser.     The three
perimeter pole earths are connected back to the  earth ing point of the
centre pole.

Dimensions  give by  LEE  for  50 to  150  kc/s..

Centre pole    ( or  tower !!)       450 feet.
Perimeter  towers                       150  feet
Spacing from centre pole to  perimeter poles          500  feet.


B.       Data  for       2  to  4  mc/s...

     Centre  pole         30   feet     high
Perimeter  poles       10  feet  high
Spacing  centre pole  to perimeter poles      33  feet.

and the    total capacity   of the three variable  condensers   ,  C1 + C2 +
C3   is
         equal  to      1500        mmfd.


The  UG  Tyupe  Vertical...

First   Model....  Design for   2  mc/s..

Horizontal  wire  is    52  foot  long.
Three     down  wires,   with    centre down lead   connected to the   mid
point of
the horizontal      wire,   (  i.e.   at the 26  foot point,  and the others
, one each side
at the 25  foot   and  the  27  foot    points..)

At the bottom , one of the out side  verticals is earthed.  The centre wire
is connected
to the  earth point of the earthed  vertical     through a variable
condenser  to the earth stake  to which  the earthed vertical is connected.
             The other outside vertical   comes down  to just above ground
level
and is  connected to the  feedline system.  The   length of the verticals
is    25    feet
for each  one..


Second  design.


Top horizontal wire is  52  foot long   supported   at   the   25  foot
level ( above
ground  ) .

The   three  25  foot  vertivals  are attached  as  follows.

First vertical is attached    to one  end of the horizontal wire and drops
down to become the  feed element.
The second  vertical drops down to become the  earthed   vertical,... one
foot away
from  the feed  vertical.
the third vertical   drops  down  from the   2     foot point  ( from the
end of the horizontal   wire )        to connect to a variable   condenser
the other side of which
connects to the earthing  stake of the centre vertical.


As it is quite a few  years ago since I made these notes  I can not remember
if there was any other data.

Perhaps a search of the    www  pages     for the  NORD    or UG  Type
vertical
might bring  forth more details.


    73     Stan,    ZL4MB          DUNEDIN  NEW ZEALAND..        23  August
1999

nnnnnnnnn