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Re: [CQ-Contest] Using Multiple Antennas in a Contest

To: Chuck <w5pr@swbell.net>
Subject: Re: [CQ-Contest] Using Multiple Antennas in a Contest
From: Luc PY8AZT <py8azt@dxbrasil.net>
Date: Sun, 23 Oct 2011 09:28:01 -0300
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
I guess, Using multi-antenna fed by a single PA is the way to go. From
Northeastern Brazil, we have 70 degrees beetwin Europe and North
America, so It makes seen to us have two antennas for each band for
quick pickup weak signals from most populated areas.

At PW7T we use 2 long boom antennas for those bands: 40, 20, 15, and
10m. All lower antenna are fixed toward Europe and upper one rotates
360 degrees. So, we use WX0B Stackboxes to select Upper, Lower or Both
at any time. Usually we use both antenna most time and concentrate on
one antenna to listen weak signals.

All PAs are Alpha 99, 91 and 374, running legal limit all the time.
So, there is no super power PA capable at the shack.

As others stated here, the station is open to receive any CQWW
representative during coming up CQWW Contest to check If we obey every
contest rules. We will be on the air again as M/2 category.

73, Luc
__
PW7T Team member
WRTC.2010 Brazilian Team Leader
PY8AZT (also PT7AG, PX8C, ZZ8Z, ZY7C)
LABRE, ARRL, CWJF & Fortaleza DX Group Member


2011/10/22 Chuck <w5pr@swbell.net>
>
> I would like to chime in here.  I use multiple antennas in contests.  (I can
> think of no other use for this.)  This is not about stacked, phased
> antennas, but antennas in different directions fed at the same time.  It has
> nothing to do with QRMing a direction you are not working.  I set up each
> band so I can feed one or all the antennas at the same time.  At the shack I
> have a homebrew aluminum box I bring all the feed lines for 10 meters into
> with relays to select any of them.  I have a simple relay "logic" circuit
> that switches a linear coax matching line in to match the impedance any time
> 2 or 3 of the feed lines are selected. (I only have 3 feed lines, some
> antennas are selected and matched on the towers.)  By cutting the
> transformer lengths to match about 20 ohms to 50 ohms, 1/2 way between the
> combined impedance of 2 and 3 antennas fed together (25 ohms and 17 ohms) I
> have a good match for any combination.  In a contest I configure the
> antennas toward the desired areas where propagation is open, feed multiple
> antennas if needed and work stations. If one is weak, I drop out antennas
> until I find the "right" one.  If there is noise on one antenna, I
> frequently drop it out to make sure it is not masking weak signals on other
> antennas. In this way, you can make rapid-fire QSO in different directions
> in contests.
>
> Chuck W5PR
>
> ----- Original Message -----
> From: "rob beaudoin" <wa1fcn@charter.net>
> To: <CQ-Contest@contesting.com>
> Sent: Friday, October 21, 2011 3:40 PM
> Subject: [CQ-Contest] Pleasant change
>
>
> > Hi Guys
> >
> > Ok please excuse my last post, I really messed that one up.  What I really
> > would like to
> > see is information on sending output from one rig to multiple antennas at
> > the same time.
> > I am experimenting with this now. The rest of my post on "all the talk of
> > cheating/bending
> > the rules/ect/ect " and feeling  I do not need to know all this holds.
> > 73 Bob WA1FCN
> > _______________________________________________
> > CQ-Contest mailing list
> > CQ-Contest@contesting.com
> > http://lists.contesting.com/mailman/listinfo/cq-contest
>
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