Oh, I am terribly sorry, that should be read 6990kHz
73
Peter
-----Original Message-----
From: Rex Lint [mailto:rex@lint.mv.com]
Sent: Dienstag, 21. April 2009 23:17
To: 'Peter Voelpel'; towertalk@contesting.com
Subject: RE: [TowerTalk] RG11 75ohm and 4 square 80m
>I first calculated the radiator length for 6090kHz (100kHz below my
>target
frequency).
Why was your target freq = 6190?
-Rex-
K1HI
Rex Lint
Merrimack, NH
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Peter Voelpel
Sent: Tuesday, April 21, 2009 4:45 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] RG11 75ohm and 4 square 80m
I did a different approach when I installed my 40m 4-Square.
I first calculated the radiator length for 6090kHz (100kHz below my target
frequency).
Then I resonated the first radiator by fine tuning it against a temporary
ground rod.
The other three radiators I made mechanically the same length.
I then installed the elevated radials (have only one each) and adjusted
their length one at the time to resonate with the radiator on exactly
6090kHz.
All four are within 10kHz the same now and I get about 18db front to back
with my present system.
Now, if I wish to install more radials, I just disconnect the installed one
and bring the new radial with the radiator to the same frequency of 6090kHz.
I am a bit space limited so probably plan to add just one more radial into
the opposite direction.
For the phasing line I use CATV cable with a dielectric similar to Cellflex
hardline and 2mm inner conductor, velocity factor is 0.86 and it fits
perfect into PL259.
73
Peter
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Paul Playford
Very important when using elevated radials: they will affect the resonant
frequency of the element. When I installed my 4 squares I first installed
two wires in the form of a 1/2 wave dipole (fed at the center) at their
final elevation above ground. Then trimmed them to length at my target
frequency of the array. Then I cut the rest of the radials to the same
length and installed them.
After all of the radials were installed I then installed the vertical
elements and tuned them per Comtek instructions against the radials.
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