[TowerTalk] Stacking 4-squares ?

[Tim Duffy]

Hello Mike:

We have been using two phased four squares at K3LR for almost 20 years. It
was N2NT's idea to do this project.

It is a very simple system to get 3 dB gain over one four square and F/B is
improved:

Two full size (quarter wavelength verticals) four squares
120 quarter wavelength radials under each element.
5/8 wavelength spacing between the centers at 3.650 MHz
Feedlines to each element are RG-11 foam - quarter wave at 3.650 MHz
Individual elements tuned to 3.455 MHz for minimum dump power at 3.650 MHz.
Dump power is -26 dB down vs. input.
Elements made from 60 ft aluminum towers (sections welded together) with a
12 ft stinger.
Simple match when using both four squares - use 3/4 wavelength of RG-213
from each Comtek box
Hook the two together (now 25 ohms) - step up back to 50 ohms with quarter
wavelength of RG-83 (35 ohm coax).
To use only one 4 square the other must be detuned. Simple to short the
Comtek box side of each vertical feedline
This reflects an open at the element feedpoint (floating quarter wavelength
elements are not resonant).

You can see the layout of the dual four squares at K3LR here:
https://www.youtube.com/watch?v=6GM_RCfU9Nc&feature=youtu.be

73
Tim K3LR

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Mike
Smith VE9AA
Sent: Monday, November 25, 2019 2:26 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Stacking 4-squares ?

I think I read somewhere that someone has done this.  Was it K3LR? W3LPL?
Some Finnish or Swedish M/M hams?

I can't seem to find it.

Where can I get some more info on this practice?

 

I am tossing around the idea of doing it on 20m..maybe with an eye to do it
on 15 and/or 10m later.

 

With my 20m 4-Square I always seem to be 10dB down on 20m compared to locals
with a 56' tower and 3 or 4 element 20m Yagis and I have really no intention
on installing any towers here soon..probably ever.

 

Looking for spacing information.what to use to "stack" them (stackmatch? - -
phasing line?)

What I might expect for gain -2.2dB?  3dB?

 

 

Thanks Mike VE9AA

 

Mike, Coreen & Corey

Keswick Ridge, NB

 

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