As Steve said , separate feedlines are the way to go.
This topic has been covered by LB Cebik W4RNL
at http://www.cebik.com/quad4a.html
Hope this helps.
73 Danny - ON7NQ -
ON7NQ@pandora.be
http://users.pandora.be/ON7NQ
----- Original Message -----
From: "Brown, James E LRDOR" <James.E.Brown@lrdor.usace.army.mil>
To: <towertalk@contesting.com>
Sent: Tuesday, February 05, 2002 3:38 PM
Subject: RE: [TowerTalk] Question about triband Quad.
>
> How would the receiving capabilities of this antenna be effected, if at
all,
> by having the one feedline as opposed to separate feedlines?
>
> Jim W4LC
>
> -----Original Message-----
> From: K7LXC@aol.com [mailto:K7LXC@aol.com]
> Sent: Sunday, February 03, 2002 1:02 AM
> To: ROBKEL@aol.com; towertalk@contesting.com
> Subject: Re: [TowerTalk] Question about triband Quad.
>
>
>
> In a message dated 2/2/02 6:23:59 PM Pacific Standard Time, ROBKEL@aol.com
> writes:
>
> > I have recently put together a 2 element triband quad. 20 & 15 M work
> good,
> > with a under 2.0:1 over full band (<1.4 over most).
> > 10m VSWR is unacceptably high (3:1 or so over full band.
> > I have checked all connections and dimensions, all OK. Feed is a single
> feed
> >
> > line through a balun and then a length of 75 ohm twinlead to a common
> > connection of all three bands.
> > I arranged to isolate just the 10 m DE, and it shows a 2:1 VSWR over
> band.
> > I was under the impression such antennas were common an presented a
good
> > match on all bands. I plan to test the balun soon, and also
considering
> a
> > 2:1 W2FMI transformer.
>
> You'll have problems when you feed a quad with the feedpoints tied
> together and using one feedline; the 20M loop will radiate when you're on
> 10M
> (14 & 28 mHz). Use 3 feedlines and your problems should be minimized.
>
> Cheers,
> Steve K7LXC
> Tower Tech
>
> ________________________________________________________________________
> Where do you get ICE bandpass filters & beverage matching boxes? The
> same place that pays for the hosting of this list: The eHam Store.
> Order online at http://store.eham.net.
> -----------------------------------------------------------------------
>
> -----
> FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
>
> ________________________________________________________________________
> Where do you get ICE bandpass filters & beverage matching boxes? The
> same place that pays for the hosting of this list: The eHam Store.
> Order online at http://store.eham.net.
> -----------------------------------------------------------------------
>
> -----
> FAQ on WWW: http://www.contesting.com/FAQ/towertalk
> Submissions: towertalk@contesting.com
> Administrative requests: towertalk-REQUEST@contesting.com
> Problems: owner-towertalk@contesting.com
>
>
________________________________________________________________________
Where do you get ICE bandpass filters & beverage matching boxes? The
same place that pays for the hosting of this list: The eHam Store.
Order online at http://store.eham.net.
-----------------------------------------------------------------------
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|