The 'Aerial' Antenna Section


The balloon kite arrangement I use involves the Helikite  Sky Hook or the Lightweight Helikite to support the antenna wire  .  The Sky Hook is larger than the 'bird scaring' range of Light Weight Helikites, and will fly in wet weather.  The two types of Helikite  that I use are highlighted.

                                       Helium Capacity      Lift No wind             Lift in Wind              Max Wind        Max Altitude

Vigilante Helikite                 0.15 m3                     0.03 Kg                  0.15 Kg                    25 mph              1,000 ft              


Lightweight Helikite            0.15 m3                     0.06 Kg                  0.18 Kg                    25 mph              1,300 ft        


Skyhook Helikite                 1.0   m3                     0.4 Kg                     1.5 Kg                      28 mph             2,000 ft      


Skyhook Helikite                 1.3 m3                       0.7 Kg                     2.5 Kg                      31 mph           2,500 ft                             


The Helikite Sky Hook will just about lift the quarter wave (40 metres) of number 14 flexiweave wire without wind, but any breeze at all takes it right up with the additional generated lift.  The designed angle of flight of the Helikites is 45 degrees or a bit more, making it not quite a true vertical but certainly a lot more vertical than an inverted 'L'.  Sometimes instead of the Sky Hook I use two Light Weight Helikites if the wind is lighter, as it two in a 'train' generates additional lift.

To deploy the balloon/kite antenna, the 12 metre SCAM12 mast is nested at 2 metres, a 4 metre fibreglass stub is inserted into the top at the 40mm spigot.  A 150 kg. breaking strain fishing swivel is attached to the top of the stub to keep twisting to a minimum.  All attachments are made with 200 kg. breaking strain Kevlar line.  On each side of the swivel is about 10 cm. of Kevlar line.  

The antenna wire to the Sky Hook is run from a small plastic insulator at the swivel to the Helikite, with the last two metres being Kevlar attached to a small high strength porcelain insulator. Another swivel at the Helikite attachment point takes care of the last of the twisting.  The final bit of additional Kevlar keeps any arc away from the attachment point and saves chasing the Helikite across the country as it flies to 1 to 2 thousand feet and drifts rapidly away. (My insurance has paid for two escapees that took off)

The Sky Hook is then released, the 40 metres of flexiweave antenna wire played out, and then the pump up mast is put into the full up position, SLOWLY, to avoid strain on the kite antenna wire.

If you don't have a collapsible mast, just a two or three metre pole, well anchored, can be used, and more kite or balloon line deployed to make up the length required for the 1/4 to 3/8 wave antenna.  Even a dog lead corkscrew available from pet shops will hold it down in most cases and then the antenna is all wire.  As they say, your mileage will vary!

The soil around where I live is very sandy, but I am not far from the North Sea.  The antennas for Top Band work well.  Here is a plot of the Helikite supported 'Protracted L' antenna, plotted with a ground loss of about 10 ohms.  That is my estimated ground loss based on measurements of antennas of a know feed impedance over perfect ground, and subtracting the theoretical value from the bridged feed point value.  I have about 60 radials from 45 to 120 feet in length.  I think this plot of the 'Protracted L' is fairly accurate.


This is the 'Protracted L' in the air


The Box Delta or the Cody War Kite (each shown on a previous page) will take the wire almost straight up to within about 20 degrees of vertical.  As the legal limit is 60 metres above ground level before you have to inform the civil aviation authorities and 60 metres is a 3/8 wave antenna on Top Band, it works out very well.  


This is how the 'Near Vertical' antenna is deployed


Here is the antenna pattern for the kite lifted 'near vertical' antenna as a 3/8 wave.  It does break pile ups !!!!!


My main source for "Top of the Line" kites is a custom kite maker.  I was very lucky to find this one and I think mine is the best in the business.  Here is her SITE.  She is not expensive, a craftsperson of the first order, and a wealth of knowledge.

Kites can be had from any large distributor, for run of the mill commercial kites from China and the USA, I use Dunstable Kites here in the UK

More on the use of kite lifted 160 metre antennas coming to this page later.....I have taken more photos, taken impedance measurements, and will have the results on this site ASAP.





Next Page, More Kite Antenna Stuff (Page 4)