The Kites
In
order to raise an antenna the kite must have sufficient lift.
This may seem obvious but all too often I have been ready
to operate and the wind has dropped. Of course, location helps
and beaches and hills are generally better with a more constant
windspeed. After only a a short time flying kites one becomes
acutely aware of the variation in windspeed and soon becomes the owner
of many kites for different conditions. Shown here are some of the
kites I have found most useful for antenna lifting.
The ideal antenna kite has sufficient lift, flies at a high angle
and is stable and predictable; the latter being important if you wish
to fly from a restricted loaction.
The kites are most often launched by extending the line to full flying
length before launch as controlling the extreme pull of the large ones
is difficult. The line is tied to a 'dog stake' screw anchor
which is also used as the station earth.
The winged box
The winged box kite is a stable flyer in both light and stronger winds
and is a cheap purchase. At approximately a metre across the kite
is easy to rig and handle. Lift is not great and it requires a
stiff breeze to lift ribbon cable, but for lifting long wires /
verticals it is ideal. On light wind days it is a useful kite to
have.
Delta Coyne
Easily my favourite kite, because of its predictable nature, the DC
flies in very light winds and when the wind drops its nose falls and it
flies like a hang glider. This action helps maintain height
between gusts on light wind days. In stronger winds it will fly
almost vertically above. I had read that the stability of the DC was legendary, and
I have to agree. I flown this kite to over 100 feet from a
suburban garden - a feat I wouldn't contemplate with any other kite.
Unfortunately the great characteristic of this kite also means
that it is now very worn and only comes out for special occaisions.
Delta
The delta is a very cost effective kite, easy to build from
scratch and available in large sizes for reasonable prices. This
9 foot model will fly in 3mph winds, but can get unstable in gusts or
as the wind increases. Adding tails significantly improves
the stability, but at the expense of lifting performance. It is
not as predictable as the DC but is still a good performer.
Cody
The Cody kite is a real beauty and always draw the crowds (this one is by DidaKites). Based on Cody's man-lifting kites, in
stronger winds it is very stable with an immense pull and is ideally
suited to lifting the antenna. It will easily self launch (hence
my youngest two children Charlie and Poppy having to hold it down for
the photo!) and once up, it will stay put for hours. The only
drawback is getting it rigged on the ground. The 8 foot span
makes insertion of the spars in a wind very difficult on your own.
However, the great thing when flying a Cody is that there always
seems to be someone around to help.
Stratoscoop 3
The Stratoscoop 3 is my heavy lifter, easily capable of
raising 3 - 4 kilos in a moderate wind and significantly more in
stronger winds. This is a very serious kite, note that kite is
attached to the line using a standard climber's karabina.
Stratoscoops are made to order by Green's of Burnley
and there are many stories of these beasts on the web.
Unlike a large power kite which can be brought to earth by the
control inherent in the design, a single line kite that cannot be
'reeled in' requires a special technique to get it down.
Generally walking it down by sliding a pully or karrabina along the
line as you walk down wind is the best way. In a strong
wind, when the anchor is being ripped from the ground the stratoscoop
certainly exercises the heart!. Stratoscoops have been used by
many professionals (like Universities and the BBC) for lifting cameras
and scientific equipment, however, one must be careful to fly them in
clear air as they are prone to turbulance.
Small Parafoils
In very high winds
(25mph and above) I use small and mid size parafoils. These
generally require a tail to ensure
stability and need to be flown in clear air. In winds of 40mph +
these are the only kites I dare to fly. In winds of this speed,
unless you are in a shelter of some kind, CW is the only radio mode to
use as wind noise in the microphone becomes too great.
Kites I would like
The requirements for antenna lifting are very similar to those of Kite
Aerial Photography (KAP) and a kite I would love to try (or at least
hear reports of) is the Sutton Flowform. If you have used this
kite I would be very interested in your experience - is it more stable
than the Stratoscoop?