Kite Antenna–(Bleeder is ready)

Static Discharge from antenna can do damage to your gear. So we need a way to discharge the static charge which can build up in the antenna.

The wire antenna can act as a capacitor against ground. Dry air breakdown voltage is about 33kV/cm with smooth surfaces. Test with other wire antennas shows, with a gap of about 2 mm, the potential difference was in the order of 6kV. Build up 1-2 times a second.

The bleeder resistor across the antenna and ground prevents the charge building up to any significant level. The bleeder resistance should be non-inductive and has to be large enough not to add any reactance and have no effects for the antenna characteristics.

Tnx Patrick (ON4CLP) who got the right components on the shelf. Everything was build in an aluminum enclosure. We used 4 x 1mOhm resistors combined with a gas discharger. Like you can see on the picture above, the antenna feed will be connected to the red connector and ground will be connected to the black connector. For the ground we have a copper tube of 80 centimeters with cable towards the connector.

On the back of the enclosure, you will find a PL-connector, we will use a coax cable to feed the MFJ – Antenna Tuner Verso II.

PS: The antenna bleeder can not be used as a LIGHTNING protector. It only will discharge our wire, while he is hanging on the kite. Due to the wind, and air conditions, static charge could build up. Even dry & cold air is more dangerous then when we have some moisture

Kite Antenna Project

The idea of the Kite Antenna is still in the CONCEPT phase.

We know yet that we would like to bring a wire of 41 meters in vertical position in the air. We bought a Kite and did already some test flights. Without wind and also without success

First time without wind; location Beerse

 

24 April 2011, location Diepenbeek

 

1 May 2011, location Nokia Siemens Networks, Herentals.

Last flight on 1st of May, we broke one front spoon (carbon), so we went next Saturday to the shop to get some carbon and also fiberglass spoons.

But during this flight we were able to put a GPS logger  (Agps 747A+), connected on the Kite (thanks Andre ON2ADR). We could measure the height during the flight. The final result was 70 meters, so good enough to connect a wire of 42 meters

Meanwhile the Antenna Bleeder is ready thanks to Patrick (ON4CLP) for the fast manufacturing of the concept we had in mind. Fixing the carbon spoon and we are ready for take of next time. Then we will add some measurements we did for the antenna. There are a lot of parameters we would like to know before we are starting to transmit on HF.

Stay tuned, more to come…

73 de ON3HF, Alex