> From: K3BU@aol.com
> To: topband@contesting.com
> Subject: Re: TopBand: Vertical Matching
To: <topband@contesting.com>
> Date: Tuesday, November 04, 1997 9:39 AM
>
> In a message dated 97-11-04 08:30:00 EST, AB5XPwrites:
>
> << For the 160 meter Contest in December we install a 1/4 wave balloon
> vertical on a ridge in southern MS. We feed it with open wire line. A
run
> of about 700-800 feet. >>
>
> Mike,
> I have used balloon 1/4 wave vertical (WA7UQV kits) both at my house and
at
> field location. I use elevated radials ( 2 or 4 of them) at 30 or 40 ft.
> using PVC pipe mast, or rooftop of the house. Radials (1/4 wave) are
sloping
> down to about 5 ft off the ground. Antenna has impedance of or close to
50
> ohms, no need to feed it with anything but coax. The only problem I found
> especially for contest is the F$%^& wind.
Dear Yuri,
We are using open wire line because we don't have 800 feet of coax.
Also, we have found that by adding a balloon at the midpoint of the
antenna, the wind problems are decreased. For a large portion of the time
the wind is blowing, one balloon is out one direction, and the other is out
the other way. It looks like some sort of oscillation, but the net result
is the vertical tends to stay in a more vertical position with the second
balloon at the mid point.
We stumbled on this when we needed extra lift one year, and now use two
balloons regularly to control some of the wind problems.
Thanks for your reply,
Mike MIchon
AB5XP
>
--
FAQ on WWW: http://www.contesting.com/topband.html
Submissions: topband@contesting.com
Administrative requests: topband-REQUEST@contesting.com
Problems: owner-topband@contesting.com
|