Re: LF: Quadrocopter antenna, sri, a bit OT

[M0FMT <m0fmt@yahoo.co.uk>]

Hi Stefan and all

 

Just dumped the old BT 19th century land line for seriously fast Tooway Data Sat Broad band and can watch all the videos in Hi Def now.

 

Just amazing footage of the Quad/Hex copters. Could one haul a wire ant to 7000ft? I guess you will try Stefan... Good luck! We will be listening.... 8kc/s?

73 es GL Pete M0FMT IO91UX

From: Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>
To: rsgb_lf_group@blacksheep.org
Sent: Tuesday, 6 August 2013, 0:11
Subject: Re: LF: Quadrocopter antenna, sri, a bit OT

Hi Warren, LF/VLF,

I just found this: http://www.youtube.com/watch?v=G3yR-GxD1is  Take a look at it. I can't find the words. I think i must have one :-)
That must be SEVERAL 100m above ground. I think we could even do VLF experiments with such a copter. Maybe a 500m vertical? I remember the weight of the wire in my 300m kite antenna test was about 1.5 kg, not more. So with 500m we could come lower than 5.17 kHz, like i did in 2010/2011.

73, Stefan/DK7FC


Am 06.08.2013 01:02, schrieb Warren Ziegler:

Stefan,

    But 100m is not better than your kite experiments!

Yes you gain control but not height. 

You will still need a battery to land the quadcopter in the event of a failure of the power carrying wire.

73 W

On Mon, Aug 5, 2013 at 6:53 PM, Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de> wrote:

Hi all,

I just gathered some informations from the web. Just one example for a, probably, suitable hexacopter to carry a LF transmit antenna.

For example a DJI F550, see a video at http://www.youtube.com/watch?v=veDrtdE6njo or http://www.youtube.com/watch?v=2QC9so2so3Y). Looks like they can easily lift 1 kg! You can fly about 10 minutes with a 5.3 Ah battery. The battery voltage is to 11.1V...14.8V. So the power consumption may be 200...300 W ! With a compact SMPS on the copter and a 2 wire line it could be possible to carry the antenna. And 100m is no problem too!!
I consider to buy one! And look this, most fascinating. http://www.youtube.com/watch?v=JecyY79K7kY

73, Stefan/DK7FC


Am 05.08.2013 15:25, schrieb Stefan Schäfer:

Am 04.08.2013 17:52, schrieb DK1IS:

[...]But with nowadays quadrocopters and a "little" reduction of the demands it should be possible to feed them from the ground with DC (or AC plus converters for reduction of current) via 2 wire line and having a good antenna too.

73,
Tom, DK1IS

That's it! So, Markus, could you ask your friend abot some technical details? What is the supply voltage of the system and power consumption (or lifetime at a certain battery charge)? Is it possible to lift 1 kg and how does it change the power consumption? It should be no problem to feed DC to the system or a compact power supply in the sky and normal 230V mains at ground (todays PSUs have an input voltage range of 85...240V AC, so a certain voltage drop on the thin wire should be no problem.
Maybe you can do some tests?

The advatages are clear. A quadrocopter keeps the position and height, even in smaller wind blasts while a balloon bounces left and right. The costs of Helium will quickly overcome the costs for a quadrocopter. Ah and such a project is simply more interesting i guess :-)

73, Stefan/DK7FC

--
73 Warren K2ORS
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