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[98.139.165.165]) by mx.google.com with ESMTPS id ci8si2211307pad.245.2013.08.06.05.37.21 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Tue, 06 Aug 2013 05:37:31 -0700 (PDT) Received-SPF: pass (google.com: manual fallback record for domain of sentto-85080895-3279-1375792638-daveyxm=virginmedia.com@returns.groups.yahoo.com designates 98.139.165.165 as permitted sender) client-ip=98.139.165.165; Authentication-Results: mx.google.com; spf=pass (google.com: manual fallback record for domain of sentto-85080895-3279-1375792638-daveyxm=virginmedia.com@returns.groups.yahoo.com designates 98.139.165.165 as permitted sender) smtp.mail=sentto-85080895-3279-1375792638-daveyxm=virginmedia.com@returns.groups.yahoo.com; dkim=pass header.i=@yahoogroups.co.uk DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoogroups.co.uk; s=oscaro; t=1375792639; bh=yCiO6vivcBii4EpHQWIO6TbOHaxMn7rTTdj76aiq9yQ=; h=Received:Received:X-Yahoo-Newman-Id:X-Sender:X-Apparently-To:X-Received:X-Received:X-Received:X-Received:X-Received:X-Received:References:To:In-Reply-To:X-MB-Message-Source:X-Received:X-MB-Message-Type:X-Mailer:Cc:Message-Id:x-aol-global-disposition:x-aol-sid:X-Originating-IP:X-eGroups-Msg-Info:From:X-Yahoo-Profile:Sender:MIME-Version:Mailing-List:Delivered-To:List-Id:Precedence:List-Unsubscribe:Date:Subject:Reply-To:X-Yahoo-Newman-Property:Content-Type; b=MnvWqp+Hr+SrzrOONoZHst4INEOoeBGVandLmgBBxpJZbGXcB+0Nej2L+2uZ2Iheg2zmMbnB3I3xtu0M01iBcYRXHANORGamnX7suJI6iGsNz9dh3NU82crvJc7csDR21GkOX81tofm4bJYQokP+18QWuQ0sRkVP4OlLdFY5H3o= DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=oscaro; d=yahoogroups.co.uk; b=dvIvct7dMh9KwfOHZ55GnYuImAhpKdPj3SWyfffNUx3mNTqDqxiaGAJCXjUBrUqj5tGqKxEXnFciIAujlPhxsQBsE6HuKFIqHpoLd1JiQd7X6PZ7UqA7+FYOUOg2kZe4ws9fAf0ktln2KOndTIPcnGh3MHWHgPPw/zpJpicWl/Q=; Received: from [66.196.81.180] by ng18.bullet.mail.bf1.yahoo.com with NNFMP; 06 Aug 2013 12:37:19 -0000 Received: from [10.193.39.5] by tg8.bullet.mail.bf1.yahoo.com with NNFMP; 06 Aug 2013 12:37:19 -0000 X-Yahoo-Newman-Id: 85080895-m3279 X-Sender: markusvester@aol.com X-Apparently-To: rsgb_lf_group@yahoogroups.co.uk X-Received: (qmail 48082 invoked by uid 102); 6 Aug 2013 12:37:02 -0000 X-Received: from unknown (HELO mtaq2.grp.bf1.yahoo.com) (10.193.84.33) by m1.grp.bf1.yahoo.com with SMTP; 6 Aug 2013 12:37:02 -0000 X-Received: (qmail 32369 invoked from network); 6 Aug 2013 12:37:02 -0000 X-Received: from unknown (HELO omr-d01.mx.aol.com) (205.188.252.208) by mtaq2.grp.bf1.yahoo.com with SMTP; 6 Aug 2013 12:37:02 -0000 X-Received: from mtaomg-mb05.r1000.mx.aol.com (mtaomg-mb05.r1000.mx.aol.com [172.29.41.76]) by omr-d01.mx.aol.com (Outbound Mail Relay) with ESMTP id B40A670000081; Tue, 6 Aug 2013 08:37:02 -0400 (EDT) X-Received: from core-dfe002a.r1000.mail.aol.com (core-dfe002.r1000.mail.aol.com [172.29.55.135]) by mtaomg-mb05.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id 7B9A8E000081; Tue, 6 Aug 2013 08:37:02 -0400 (EDT) References: <52003135.1040807@iup.uni-heidelberg.de> To: rsgb_lf_group@blacksheep.org In-Reply-To: <52003135.1040807@iup.uni-heidelberg.de> X-MB-Message-Source: WebUI X-Received: from 194.138.39.53 by webmail-m221.sysops.aol.com (64.12.107.171) with HTTP (WebMailUI); Tue, 06 Aug 2013 08:37:01 -0400 X-MB-Message-Type: User X-Mailer: Webmail 37953-BASIC Cc: rsgb_lf_group@yahoogroups.co.uk Message-Id: <8D060B8C892D2CF-2024-995@webmail-m221.sysops.aol.com> x-aol-global-disposition: G x-aol-sid: 3039ac1d294c5200edee77a3 X-Originating-IP: 10.193.84.33 X-eGroups-Msg-Info: 1:12:0:0:0 From: Markus Vester X-Yahoo-Profile: df6nm Sender: rsgb_lf_group@yahoogroups.co.uk MIME-Version: 1.0 Mailing-List: list rsgb_lf_group@yahoogroups.co.uk; contact rsgb_lf_group-owner@yahoogroups.co.uk Delivered-To: mailing list rsgb_lf_group@yahoogroups.co.uk List-Id: Precedence: bulk List-Unsubscribe: Date: Tue, 6 Aug 2013 08:37:01 -0400 (EDT) Subject: [rsgb_lf_group] Re: LF: Quadrocopter antenna, sri, a bit OT Reply-To: rsgb_lf_group@yahoogroups.co.uk X-Yahoo-Newman-Property: groups-email-ff-m Content-Type: multipart/alternative; boundary="--------MB_8D060B8C89EB9AF_2024_24F7_webmail-m221.sysops.aol.com" Status: O X-Status: X-Keywords: X-UID: 3845 ----------MB_8D060B8C89EB9AF_2024_24F7_webmail-m221.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Hi Stefan, LF, =C2=A0 the quadrocopter which we tried was a DJI Phantom. It is smaller than the F= 550 and currently goes for around 570 Euro (ready to fly, including battery= and a 2.4 GHz remote control). A similarly equipped model, Blade 350QX, sh= ould become available soon for about 450 Euro. Very light quadrocopters can= be had for as little as 60 Euro but they could presumably lift only short = and very thin wires. =C2=A0 With GPS, gyro and compass sensors, the Phantom was indeed extremely easy t= o fly even by an unexperienced person like me. With 11.8V 2.2Ah LiPo batter= y it will stay aloft for 10 to 15 minutes, so power consumption must be aro= und 120 W. The motors are said to be able to stand continuous duty. Lifting= capability should be around 0.3 kg, and my friend intends to install a fir= st-person-view video cam later. We have not tried to lift a wire or string = yet, so I don't know how much the behaviour would be affected eg. by wind d= rag on the wire.=C2=A0With 6 m/s climb rate, the heli could theoretically g= o up to 2000m and more on a battery charge. The remote control is specified= for 300m range, which could probably be fixed by a higher gain 2.4 GHz tra= nsmit antenna.=20 =C2=A0 Yes power could be fed continuously by making the LF antenna a twin wire. O= n the ground either an Austen transformer or a bifilar wound loading coil c= ould be used (maybe by splitting up groups of strands in the RF litz). The = heli then cannot be separated by a distance from the antenna tip which may = aggravate potential EMC issues. Alternatively, I am still wondering whether= enough charging power could be extracted by capacitive coupling to the LF = transmission... =C2=A0 Currently in Germany there seem to be no general restrictions about flying = light helis (less than 2 kg) even over inhabited terrain. I am not sure tho= ugh about legal implications of a tethering wire or going to higher altitud= es. Basic liability insurance seems definitely recommended and can be obtai= ned eg by joining a model flight club. While hovering over houses after sun= set with bright green and LED bars on, we were confronted by one neighbour = who strongly expressed her dislike of the activity. People mostly seem to b= e concerned of "Papparazzi drones" invading their precious privacy, the aco= ustic noise when flying low, and surely the fear that these things might en= d up falling onto their heads. =C2=A0 Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Stefan Sch=C3=A4fer <Stefan.Schaefer@iup.uni-heidelberg.de> An: rsgb_lf_group <rsgb_lf_group@blacksheep.org> Verschickt: Di, 6 Aug 2013 1:43 am Betreff: Re: LF: Quadrocopter antenna, sri, a bit OT Hi Warren, LF/VLF, I just found this: http://www.youtube.com/watch?v=3DG3yR-GxD1is=C2=A0 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 experi= ments with such a copter. Maybe a 500m vertical? I remember the weight of t= he wire in my 300m kite antenna test was about 1.5 kg, not more. So with 50= 0m 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, =C2=A0 =C2=A0 But 100m= is not better than your kite experiments! Yes you gain control but not height.=C2=A0 You will still need a battery to land the quadcopter in the event of a fail= ure of the power carrying wire. 73 W On Mon, Aug 5, 2013 at 6:53 PM, Stefan Sch=C3=A4fer <Stefan.Schaefer@iup= .uni-heidelberg.de> wrote: Hi all,=20 I just gathered some informations from the web. Just one example for a, pro= bably, suitable hexacopter to carry a LF transmit antenna.=20 For example a DJI F550, see a video at http://www.youtube.com/watch?v=3DveD= rtdE6njo or http://www.youtube.com/watch?v=3D2QC9so2so3Y). Looks like they = can easily lift 1 kg! You can fly about 10 minutes with a 5.3 Ah battery. T= he 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=3DJecyY79K7kY 73, Stefan/DK7FC Am 05.08.2013 15:25, schrieb Stefan Sch=C3=A4fer:=20 Am 04.08.2013 17:52, schrieb DK1IS: [...]But with nowadays quadrocopters an= d a "little" reduction of the demands it should be possible to feed them fr= om 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 detail= s? What is the supply voltage of the system and power consumption (or lifet= ime 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 vol= tage 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 o= f Helium will quickly overcome the costs for a quadrocopter. Ah and such a = project is simply more interesting i guess :-) 73, Stefan/DK7FC --=20 73 Warren K2ORS =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 WD2XGJ=20 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 WD2XSH/23 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 WE2XEB/2 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 WE2XGR/1 Re: LF: USA issued 68 to 76 kHz band with 10 W ERP=20 Von: Markus Vester <markusvester@aol.com>=20 An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>=20 Datum: So, 4 Aug 2013 9:47 am=20 =C2=A0 ...Yesterday night a friend showed me his new GPS-stabilized quadrocopter. = It's stunning how it could just about be parked in midair, despite some lat= eral winds. Seems that would make a great antenna carrier! Not all of the n= eighbour's seemed to enjoy it as much as we did...=20 =C2=A0 Best 73, Markus (DF6NM) ----------MB_8D060B8C89EB9AF_2024_24F7_webmail-m221.sysops.aol.com Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable  
=20=20=20=20=20=20 =20=20=20=20=20=20

Hi Stefan, = LF,
 
the quadrocopter which we tried was a DJI Phantom. It is smaller than = the F550 and currently goes for around 570 Euro (ready to fly, including ba= ttery and a 2.4 GHz remote control). A similarly equipped model, Blade 350Q= X, should become available soon for about 450 Euro. Very light quadrocopter= s can be had for as little as 60 Euro but they could presumably lift only s= hort and very thin wires.
 
With GPS, gyro and compass sensors, the Phantom was indeed extremely e= asy to fly even by an unexperienced person like me. With 11.8V 2.2Ah LiPo b= attery it will stay aloft for 10 to 15 minutes, so power consumption must b= e around 120 W. The motors are said to be able to stand continuous duty. Li= fting capability should be around 0.3 kg, and my friend intends to install = a first-person-view video cam later. We have not tried to lift a wire or st= ring yet, so I don't know how much the behaviour would be affected eg. by w= ind drag on the wire. With 6 m/s climb rate, the heli could theoretica= lly go up to 2000m and more on a battery charge. The remote control is spec= ified for 300m range, which could probably be fixed by a higher gain 2.4 GH= z transmit antenna.
 
Yes power could be fed continuously by making the LF antenna a twin wi= re. On the ground either an Austen transformer or a bifilar wound loading c= oil could be used (maybe by splitting up groups of strands in the RF litz).= The heli then cannot be separated by a distance from the antenna tip which= may aggravate potential EMC issues. Alternatively, I am still wondering wh= ether enough charging power could be extracted by capacitive coupling to th= e LF transmission...
 
Currently in Germany there seem to be no general restrictions about fl= ying light helis (less than 2 kg) even over inhabited terrain. I am not sur= e though about legal implications of a tethering wire or going to higher al= titudes. Basic liability insurance seems definitely recommended and can be = obtained eg by joining a model flight club. While hovering over houses afte= r sunset with bright green and LED bars on, we were confronted by one neigh= bour who strongly expressed her dislike of the activity. People mostly seem= to be concerned of "Papparazzi drones" invading their precious privacy, th= e acoustic noise when flying low, and surely the fear that these things mig= ht end up falling onto their heads.
 
Best 73,
Markus (DF6NM)

-----Urspr=C3=BCngliche Mitteilung-----
Von: Stefan Sch=C3=A4fer <Stefan.Schaefer@iup.uni-heidelberg.de>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Di, 6 Aug 2013 1:43 am
Betreff: Re: LF: Quadrocopter antenna, sri, a bit OT

Hi Warr= en, LF/VLF,

I just found this: http://www.youtu= be.com/watch?v=3DG3yR-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 weig= ht 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:=20
Stefan,=20
    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 S= ch=C3=A4fer <Stefan.Schaefer@iup.uni-heidelberg.de> wrote:=
Hi all,

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

For example a DJI F550, see a video at http://www.youtube.com/watch?v=3DveD= rtdE6njo or http://www.youtube.com/watch?v=3D2QC9so2so3Y). Looks li= ke they can easily lift 1 kg! You can fly about 10 minutes with a 5.3 Ah ba= ttery. The battery voltage is to 11.1V...14.8V. So the power consumption ma= y be 200...300 W ! With a compact SMPS on the copter and a 2 wire line it c= ould 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=3DJecyY79K7kY

73, Stefan/DK7FC


Am 05.08.2013 15:25, schrieb Stefan Sch=C3=A4fer:=20

Am 04.08.2013 17:52, schrieb DK1IS:=20
[...]But with nowadays quadrocopters and a "little" reduction of the d= emands it should be possible to feed them from the ground with DC (or AC pl= us converters for reduction of current) via 2 wire line and having a good a= ntenna too.

73,
Tom, DK1IS

That's it! So, Markus, could you ask your friend abot some technical detail= s? What is the supply voltage of the system and power consumption (or lifet= ime 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 vol= tage 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 o= f 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
                WD2XGJ
                WD2XSH/23
                WE2XEB/2
                WE2XGR/1

Re: LF: USA issued 68 to 76 kHz band with 10 W ERP
Von: Markus Vester <markusvester= @aol.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Datum: So, 4 Aug 2013 9:47 am
 
...Yesterday night a friend showed me hi= s new GPS-stabilized quadrocopter. It's stunning how it could just about be= parked in midair, despite some lateral winds. Seems that would make a grea= t antenna carrier! Not all of the neighbour's seemed to enjoy it as much as= we did...
 
Best 73,
Markus (DF6NM)

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