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[TowerTalk] Stacking & Phasing KT34XA's

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Subject: [TowerTalk] Stacking & Phasing KT34XA's
From: n3rr@erols.com (Bill Hider, N3RR)
Date: Sat, 13 Jun 1998 17:46:48 +0100

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David,

Yes, you may combine the feedlines to antennas on different towers, but will
prpbably  not see any improvement in signal strength one over  the other at
the heights you mention.   A high antenna and a low antenna on different
towers might show one better over the other due to arrival/takeoff angles
based on band condx.  (See my homepage. I have a 10M beam @ 149 ft on one
tower and an identical antenna on another tower @ 52 ft.  The towers are 125
ft apart).

BTW, K3MM uses a three stack of KT-34XAs.  I don't recall the heights.

The reason the antennas must be in the same vertical plane and separated by a
distance, X, (as is discussed by W2PV in his book)  to see any stacking gain
is due to ground reflection and subsequent pattern enhancement due thereto.
A good source for you to read is: Yagi Antenna Design, by Dr. James L.
Lawson, W2PV, published by ARRL.  Chapter 6 discusses stacking Yagis in
detail.

I will discuss, on my homepage, the stacking decision I made, the modelling
of the antennas, and the implementation .  I am adding to the site every
week.  Check back frequently:

http://www.erols.com/n3rr

Bill Hider, N3RR
N3 Ring Rotor
http://www.erols/n3rr
Authorized TIC Representative


DavidC wrote:

> I am acquiring two used KT34XA's (instead of the TH7 and TH6DXX).  I am
> considering either stacking them on a single tower or placing them on
> separate towers where they will be at about 40 feet and 50 feet above dry
> gravely rocky ground.
> I see in the KLM FAQ that stacked and phased KT34XA's on a single tower
> must be over 35 feet apart!  Wow! & why?
> Can two KT34XA's be combined if on different towers at different heights?
> The towers will be about 50 feet apart I believe.
> Thanks & 73, DavidC  AA1FA
>
> --
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<HTML>
David,

<P>Yes, you may combine the feedlines to antennas on different towers,
but will prpbably&nbsp; not see any improvement in signal strength one
over&nbsp; the other at the heights you mention.&nbsp;&nbsp; A high antenna
and a low antenna on different towers might show one better over the other
due to arrival/takeoff angles based on band condx.&nbsp; (See my homepage.
I have a 10M beam @ 149 ft on one tower and an identical antenna on another
tower @ 52 ft.&nbsp; The towers are 125 ft apart).

<P>BTW, K3MM uses a three stack of KT-34XAs.&nbsp; I don't recall the heights.

<P>The reason the antennas must be in the same vertical plane and separated
by a distance, X, (as is discussed by W2PV in his book)&nbsp; to see any
stacking gain is due to ground reflection and subsequent pattern enhancement
due thereto.&nbsp; A good source for you to read is: Yagi Antenna Design,
by Dr. James L. Lawson, W2PV, published by ARRL.&nbsp; Chapter 6 discusses
stacking Yagis in detail.

<P>I will discuss, on my homepage, the stacking decision I made, the modelling
of the antennas, and the implementation .&nbsp; I am adding to the site
every week.&nbsp; Check back frequently:

<P><A HREF="http://www.erols.com/n3rr";>http://www.erols.com/n3rr</A>

<P>Bill Hider, N3RR
<BR><B><FONT COLOR="#FF0000">N3 R</FONT></B>ing <B><FONT 
COLOR="#FF0000">R</FONT></B>otor
<BR><A HREF="http://www.erols/n3rr";>http://www.erols/n3rr</A>
<BR><B><FONT COLOR="#3366FF">Authorized TIC Representative</FONT></B>
<BR>&nbsp;

<P>DavidC wrote:
<BLOCKQUOTE TYPE=CITE>I am acquiring two used KT34XA's (instead of the
TH7 and TH6DXX).&nbsp; I am
<BR>considering either stacking them on a single tower or placing them
on
<BR>separate towers where they will be at about 40 feet and 50 feet above
dry
<BR>gravely rocky ground.
<BR>I see in the KLM FAQ that stacked and phased KT34XA's on a single tower
<BR>must be over 35 feet apart!&nbsp; Wow! &amp; why?
<BR>Can two KT34XA's be combined if on different towers at different heights?
<BR>The towers will be about 50 feet apart I believe.
<BR>Thanks &amp; 73, DavidC&nbsp; AA1FA

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