Done it with baluns and with using 50 ohm coax feed (without baluns)
and could never tell the difference. In my opinion, the gain in purity
of using the balun is neglible and while it is likely will be a
slightly better balanced arrangement, I don't think it would matter
(at least not to me). I have also done the 70 ohm coax transformers to
get to 50 ohms on each band (regular quad).
I have wondered about using feeders and a tuner with multiband wires
(10/15/17/20) all tied to the feeder together and with the feeder
switched via a relay box with the regular quad (8-9 foot boom) to get
as close to a balanced line match as possible (not ohm, but balanced
load). With a spider boomed quad, all feeds are close to 50 ohm
already and we are once again talking about balance, not match. I am
putting up a tower in the near future and will likely be using a quad
once again, so I too would like to hear comments from users.
Mike, k5wmg
Pipe Creek, Texas
Green cars, slow boats, big dogs, and summers off to write
Please do not print this e-mail unless it is completely necessary
On Sat, Jan 17, 2009 at 5:49 PM, N7mal <n7mal@citlink.net> wrote:
> I'm an 'ole-timer'. I have been using quads on/off for 50 years. I've used
> them in California, Illinois, Okinawa, Thailand etc etc. I have never, let
> me repeat NEVER, used any kind of balun device. All my quads have been 3
> banders and I have tied all 3 loops together to one feedline. Yes it takes a
> little more time to get everything adjusted, SWR, f/b, etc, but all those
> quads performed and performed very well. Unless someone can show me
> ''''side-by-side'''' improvement I won't change. Theoretical software
> designs are NOT side-by-side. I want to see a 'real-world' difference.......
> Best 73
>
>
> MAL
> N7MAL
> BULLHEAD CITY, AZ
> http://www.n7mal.com
> Everyone in the world is
> entitled to be burdened
> by my opinion
>
>
> ----- Original Message -----
> From: John King
> To: towertalk@contesting.com
> Sent: Saturday, January 17, 2009 20:34
> 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
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|