[TowerTalk] A Capacitively Fed 102 Degree Vertical for 160 Meters

[tedc at nucleus.com]

Doug,

With your inverted L, how high is the vertical
section and what is it made of?  Also how long is the
horizontal section and how is it made.  I will see if
I can find a schematic of the SA2550 so that I know
how it is fed.  What do you use for static suppression?

Ted VE6AMR



------- Original Message -------
>From    : Doug Smith[mailto:dougsmith at wavecable.com]
Sent    : 3/23/2015 9:03:19 PM
To      : towertalk at contesting.com
Cc      : 
Subject : RE: [TowerTalk] A Capacitively Fed 102
Degree Vertical for 160 Meters

 I use an inverted L for 160 with an old Heathkit
SA2550 at the base of the
vertical element.  The 2550 is an electrically driven
large variable
capacitor, remotely tuned/turned from the shack.  I
use 4 elevated radials
and the base of the vertical is mounted on top of a
12’ piece of pressure
treated 2x4 buried in about 2’ of concrete (hence the
top of the 2x4 and the
SA2550/base of the vertical element is about 10’
above ground, as are the
radials).  In this fashion, the radials are not
tuned.  The vertical element
is tuned by varying the capacitance in the SA2550.  I
can easily achieve SWR
of 1:1 over the whole 160m band in this fashion.

 

By the way, I use the same system for a ¼ wave 80
meter vertical with the
same results:  1:1 over the entire 75/80 meter band,
varying only the
SA2550.

 

Now, here’s the hard part:  finding an SA-2550.

 

73, Doug W7ZZ  

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