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Date: Thu, 08 Aug 2013 20:34:11 +0200
From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= <Stefan.Schaefer@iup.uni-heidelberg.de>
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References: <5202DE92.4040507@virginbroadband.com.au> <001101ce9428$e14548e0$0201a8c0@marco09cqcdi12>
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Subject: Re: LF: Re: [OT] Quadrocopter antenna
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Status: O

Hi Marco,

Am 08.08.2013 13:17, schrieb Marco Cadeddu:
> Beyond my concerns, my congrats in advance if somebody will try it!
>
> 73 de Marco IK1HSS

Yesterday i had a phone call to a German shop who sells that DJI F550 
hexacopter. I got some more technical deteils and prices. Without the 
camera option, just the flying hexacopter, LiPo accus, remote control, 
GPS navigation + sensors, 2.4 GHz link hardware, charging station, the 
costs are in the range of 1000 EUR.
That is more expensive than my car (10 years ago)! :-)
Of course it would be most fascinating, not only for amateur radio 
experiments. Anyway i still fight with myselfe if i should invest so 
much money for that stuff.

On the other side i'm dreaming (!) ;-) about a 500m vertical or so. 
Think about a MF transmitter that is connected to an antenna wire of 
variable length. The ground losses are low, maybe here on the top of the 
building. An amperemeter is already connected. The current is low, 
first. Then you start the hexacopter and start to lift it. The wire is 
rolled up and connected at the far end. Then the height reaches lambda/4 
and you can suddenly see the antenna current rising :-) As long as the 
system is running on batteries only, one could use a simple 
non-conducting line, say 20m long. Guess there will be no EMS problems 
then. A power supply from the ground is a complete differnt thing.

Could it be possible to rise a lambda/4 for 2200m?

I have an idea: You will buy the equipment and i do the experiments, for 
you, and will inform you about the results! :-)

73, Stefan/DK7FC