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A Top Band 1/4 wave vertical?
On 2015-04-18 08:38:31 +0000, gareth said:
This current interest (and privacy furore) about drones set me thinking, what an interesting way to elevate a TopBand vertical, but being a temporary structure, not breaching any planning permission (Brit) or zonal (Yank) restrictions. One problem would be the flight time / battery life, so one approach could be to power the drone through the antenna cable (much as with mast-head preamps), in which case, being tethered, it would no longer be a drone! The power considerations, however, would call for too heavy a cable to be lifted aloft, so, taking the cure from the electricity grids, perhaps the solution would be to power with 1kV AC (say, 10kHz, to reduce the sizes of aloft transformers) going up a twin feeder, with the top band excitation driving both of the AC feeder wires in parallel? (Not too dissimilar in principle from the electicity grid using Pilot Tone protection) Gareth G4SDW PS. By varying the frequency and / or phase of the 1kV AC, the positioning of the ex-drone woulc be controlled thatway. How about a tethered helium balloon instead? This way you don't have to worry about powering the thing. Bell wire will handle 100 watts all day without turning into smoke. You could use some SpiderWire kevlar fishing line to make a few tethers so that the balloon doesn't whip around too fiercely in the wind, and it would require no power at all. |
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