A fine day and and very little breeze, it must be time for park activity. Harry, ZL1BK had already set up vertical and horizontal antennas for the ongoing signal / noise comparison experiments when Dave, ZL1DL arrived with a new kite. There was near zero wind at ground level, suggesting it might be a struggle flying a kite, but higher up, tree leaves were gently rustling.
Dave’s previous “antenna lifter” could elevate a 1/4 wave wire (on 40m) when the wind was noticeable. Of course a 1/4 wave is problematic in that you want the feedpoint to also connect to ground or radials – not the easiest when your top support won’t stay still. By using a halfwave, the feedpoint does not need to be tied down at the ground. Also, the high current part of the antenna (the centre of the dipole) gets substantially elevated, and so the antenna should provide superior performance over a quarter wave wire.
So, today we are trying to lift a 1/2 wave in a lighter breeze than we historically needed for a quarter wave. Twice the antenna in less breeze? As Gimli, the dwarf, in the Lord of the Rings so eloquently put it: “Certainty of death, small chance of success. What are we waiting for?”
Actually, the new kite has a 2m wingspan compared to the 1.6m width for the previous “junior” version and so just might provide the increased lift capability we are looking for.
As always – click an image for a bigger version
The kite was launched and then the top of the antenna was attached to the kite string, some tens of metres down from the kite The kite line was then reeled out until the the feeder coax started leaving the ground. With around 10m of coax in the air, the kite line was anchored. The breeze was so relatively calm and the kite so stable that the kite line did not need a person managing it.
Unfortunately, 40m propagation was not playing ball and the only contact made was to a SOTA station; otherwise all was very quiet. It will be interesting to test the new kite’s stability and lifting capability in a slightly higher breeze. With a max allowable flight height of 120m, an 80m 1/2 wave endfed / full wave on 40 is a possability!
Somewhat difficult to capture the kite, antenna and operators in the same pic!
And if you were wondering what Harry was looking upwards at, while lying on the ground; he was concentrating on taking the photo that shows all:
