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-----Original Message-----
From: Phil Clements <philk5pc@tyler.net>
To: topband@contesting.com <topband@contesting.com>
To: <towertalk@contesting.com>
Date: Monday, July 05, 1999 5:29 PM
Subject: Need Help Resonating 160m Vertical
I have a ground plane that is a 132 foot vertical radiator (Rohn 25) =
with 3
154 foot radials. The insulator is at the 60 foot level of the tower, =
along with the
radials. The radials are floating, and connected to the braid of the =
coax feed line.
The vertical radiator connects to the center conductor of the feedline. =
A 1:1 current
balun is in place at the feed point. The radials slope at a 20 degree =
angle from 60 feet
down to 10 feet AGL. The system as installed resonates on 1520 khz with =
a vswr of
1.16:1, impedance is 43 ohms @ the feedpoint.
=20
How do I move the resonant frequency up to 1830 khz? I have tried =
several series caps
at the feed point, but am getting nowhere other than into great physical =
shape climbing
the tower every day! I am stuck with the lengths above as the radials =
are also guy wires.
Any ideas on what a tuning/matching network at the feedpoint would look =
like?
=20
If someone has time to model this antenna for me, I would be most =
greatful. Directly
under each radial is a ground screen consisting of 3-160 foot radials.
=20
All ideas and inputs appreciated!
=20
(((73)))
Phil, K5PC
=20
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<DIV><FONT face=3DArial size=3D2><B>-----Original =
Message-----</B><BR><B>From:=20
</B>Phil Clements <<A=20
href=3D"mailto:philk5pc@tyler.net";>philk5pc@tyler.net</A>><BR><B>To: =
</B><A=20
href=3D"mailto:topband@contesting.com";>topband@contesting.com</A> <<A =
href=3D"mailto:topband@contesting.com";>topband@contesting.com</A>><BR>=
To: <towertalk@contesting.com>
<B>Date:=20
</B>Monday, July 05, 1999 5:29 PM<BR><B>Subject: </B>Need Help =
Resonating 160m=20
Vertical<BR><BR></DIV></FONT>
<DIV><FONT color=3D#000000 size=3D2>I have a ground plane =
that is a 132=20
foot vertical radiator (Rohn 25) with 3</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>154 foot radials. The insulator is =
at the 60=20
foot level of the tower, along with the</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2>radials. The radials are floating, =
and connected=20
to the braid of the coax feed line.</FONT></DIV>
<DIV><FONT size=3D2>The vertical radiator connects to the center =
conductor of the=20
feedline. A 1:1 current</FONT></DIV>
<DIV><FONT size=3D2>balun is in place at the feed point. The radials =
slope at a 20=20
degree angle from 60 feet</FONT></DIV>
<DIV><FONT size=3D2>down to 10 feet AGL. The system as installed =
resonates on 1520=20
khz with a vswr of</FONT></DIV>
<DIV><FONT size=3D2>1.16:1, impedance is 43 ohms @ the =
feedpoint.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>How do I move the resonant frequency up to 1830 khz? =
I have=20
tried several series caps</FONT></DIV>
<DIV><FONT size=3D2>at the feed point, but am getting nowhere other than =
into=20
great physical shape climbing</FONT></DIV>
<DIV><FONT size=3D2>the tower every day! I am stuck with the lengths =
above as the=20
radials are also guy wires.</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Any ideas on what a tuning/matching network at the =
feedpoint=20
would look like?</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>If someone has time to model this antenna for me, I =
would be=20
most greatful. Directly</FONT></DIV>
<DIV><FONT size=3D2>under each radial is a ground screen consisting of =
3-160 foot=20
radials.</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>All ideas and inputs appreciated!</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>(((73)))</FONT></DIV>
<DIV><FONT size=3D2>Phil, K5PC</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV></BODY></HTML>
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