I feed mine with Dual LMR-400 to the rotor, then RG213 to a relay box that
switches in one loop at a time.
Feeding the loop with shielded 100ohm line I don't worry about chokes, etc.
At the shack I have a small 2:1BALUN that brings it all back to 52ohms.
Quietest feedline I've ever had...
73,
dave
wa3gin
----- Original Message -----
From: "John King" <k5pgw@yahoo.com>
To: <towertalk@contesting.com>
Sent: Saturday, January 17, 2009 3:34 PM
Subject: [TowerTalk] A poll of Cubical Quad qwners
> Hello to all on the List. I decided that I needed to join the list since I
> have antenna questions and this is where the knowledgeable hams, regarding
> antenna things, hang out.
>
> I am ready to install my 2 element, five band Cubex Cubical Quad on my
> tower and have been anguishing over whether to install Choke baluns for
> each band.
>
> I am feeding the quad with separate coaxial matching transformers for each
> band supplied by Cubex.
>
> Question: How many of you, using Cubical Quads feed them directly with
> Coax cable and how many of you install a balun and what type? Since I am
> feeding each, of the five elements, separately, if I use the unbalanced to
> balanced device such as a Choke coil, five separate choke coils (baluns)
> would be required.
>
> For those of you, who have fed them both ways, what actual differences
> have you experienced in quad performance with and without the balun?
>
> I spoke with W5ZR, this morning, at the Hammond, Louisiana Hamfest about
> this subject and he recommended going with direct coax feed without the
> unbalanced to balanced device. He has two large quads and is happy with
> the manner in which he feeds them.
>
> I am not into "knat's eye performance", I just want the quad to perform
> well. I also don't want to build any problems into the array due to the
> fact that it will be at least 75 feet on a fixed/guyed tower.
>
> For those of you who received my earlier query about resonant freq with
> the 20 meter antenna wires two feet off the ground, I learned that the 20
> meter element is resonant at 14.000.00 mhz that close to the ground
> according to my antenna analyzer. I am pleased with that resonant point
> because I know the resonant point will rise, as the antenna is raised to
> 75 feet, and the ground capacitance diminishes.
>
> If this topic, (balun fed quads) has been covered previously, I would
> appreciate it if you would so direct me to the archives. Your knowledge,
> based upon your experience, will be greatly appreciated on this subject
> (balun feeding quads). Thanks and 73, John, K5PGW
>
>
>
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