Return-Path: X-Spam-DCC: paranoid 1169; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=BAYES_00,HTML_50_60, HTML_MESSAGE,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id s9AAMvYL031513 for ; Fri, 10 Oct 2014 12:23:00 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1XcXE7-0002E5-Db for rs_out_1@blacksheep.org; Fri, 10 Oct 2014 11:15:11 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1XcXE7-0002Dw-0l for rsgb_lf_group@blacksheep.org; Fri, 10 Oct 2014 11:15:11 +0100 Received: from smtpa1.mediabeam.com ([194.25.41.13]) by relay1.thorcom.net with esmtps (TLSv1.2:DHE-RSA-AES256-GCM-SHA384:256) (Exim 4.82) (envelope-from ) id 1XcXE4-0007DI-I4 for rsgb_lf_group@blacksheep.org; Fri, 10 Oct 2014 11:15:09 +0100 Received: from MAILBACKEND3 (cluster06.xworks.net [10.100.1.80]) by smtpa1.mediabeam.com (Postfix) with ESMTP id 4A6886148E for ; Fri, 10 Oct 2014 12:15:07 +0200 (CEST) X-DKIM-Result: Domain=kabelmail.de Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kabelmail.de; s=mail; t=1412936107; bh=z/vlmCE4WCLn4LqkD06IWk8pS6l9uD6g0AXafGyp8tU=; h=Date:From:To:Subject:References:In-Reply-To; b=sNvSl7HaKD46QHmk3Dns3TcyKWbUK6gELR46LkYJgrsNvSYE2TDddkeTJwBYsnQ2d kiQV2RqbtDFEBpMvOTiud1mkJXvfdffqVUfp5CXro9yhZUmfNN3mkIjY28i4pyoTPF aUiaFiEsCsNQaHD/fQ6EkmfnkICGRSi8WrtTmeng= Received: from [192.168.178.33] (ip25042136.dynamic.kabel-deutschland.de [37.4.33.54]) (authenticated bits=0) by smtpa.mediabeam.com with ESMTP id s9AAF28M005068 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Fri, 10 Oct 2014 12:15:04 +0200 X-mediaBEAM-Originating-IP: [37.4.33.54] X-mediaBEAM-AUTHID: [DK1IS@kabelmail.de] Message-ID: <5437B1B5.6070007@kabelmail.de> Date: Fri, 10 Oct 2014 12:15:17 +0200 From: DK1IS User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.6.0 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <8D1B1F63855FC23-95C-9269@webmail-vm139.sysops.aol.com> <5436F6CC.5070504@gmail.com> In-Reply-To: <5436F6CC.5070504@gmail.com> X-mediaBEAM-AuthCheck: route13 X-mediaBEAM-AuthScore: 0.0/5.0, scanned in 2.117sec X-Scan-Signature: c7a664e36c9ca637ce420897bb72a08a Subject: Re: LF: ELF communications ? Content-Type: multipart/alternative; boundary="------------010906090509080701020904" X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: RO X-Status: X-Keywords: X-UID: 741 This is a multi-part message in MIME format. --------------010906090509080701020904 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by smtpa.mediabeam.com id s9AAF28M005068 Hi Stefan, interesting stuff! Keep in mind these oil burner ignition transformers=20 are designed to feed a spark with high ignition but low burning voltage=20 - nearly short circuit. So they have a large stray inductance and=20 resistance and a current limiting characteristc. Furthermore they are=20 only suitable for intermittend service (33% within 3 minutes as you see=20 from the label) and the middle of the secondary is usually connected to=20 the case. I used 6 of them in parallel for feeding a tesla-transformer=20 built by students during my former job at FH Amberg. But you shold try=20 it anyway. Nice your high power capacitor battery - reminds me to an own project=20 during my promotion at TU Braunschweig in the 70s of last century ;-).=20 Our institute made R+D on arcs and sparks and built a synthetic switch=20 testing facility for medium voltage vacuum switches. Before breaking an=20 LC circuit made a current of 50 kA for two halfwaves of 50 Hz and after=20 breaking there was a recovering voltage abot 60 kV at some kHz. Dont=20 know the components data anymore but there was a lot of stored energy=20 and we had to develop special fuses for each capacitor to avoid=20 explosions in case of a component failure. At that time I devloped the=20 central electronic control unit for the whole testing site - some severe=20 emc problems had to be solved successfully! Later on the had a lot of=20 trouble substituting all those large PCB filled capacitors ... Verdammt=20 lang her, verdammt lang her! Wishing you good results with your test! 73, Tom, DK1IS www.qrz.com/db/dk1is Am 09.10.2014 22:57, schrieb DK7FC: > Hi Markus, > > Thanks for the calculations. We will see the results. > I do take care. In my promotion project at TU Darmstadt i daily worked=20 > with a capacitor battery having 15 kV / 12000 uF, see an image showing=20 > 1/3 of the battery at=20 > https://dl.dropboxusercontent.com/u/19882028/IMG_8073.JPG Would be=20 > fine for a tube PA ! :-) > > Once again the PA has some EMC problems and i cannot run the full=20 > power. Hope to fix that tonite... > > 73, Stefan > > > Am 09.10.2014 18:35, schrieb Markus Vester: >> Stefan, >> this could work. In the capacitive near-field range, the electrical=20 >> field would be >> E =3D voltage * capacitance * effective height / (2 pi epsilon0) /=20 >> distance ^3 >> With 10 kV on your antenna capacitance and height, you'd get about=20 >> 0.15 mV/m at 2.4 km, maybe 14 dB stronger than ZEVS. >> Take care! Touching 10 kV on 136 kHz will severly burn you. But on=20 >> 136 Hz it would kill you, unless the current is safely limited to a=20 >> few mA. >> 73, Markus >> >> >> -----Urspr=C3=BCngliche Mitteilung----- >> Von: DK7FC <73dk7fc@googlemail.com> >> An: rsgb_lf_group >> Verschickt: Do, 9 Okt 2014 2:51 pm >> Betreff: LF: ELF communications ? >> >> >> >> >> Hi ELF, >> >> =20 >> >> This afternoon i'm attempting to transmit on my INV-L on 136.172 Hz = (not >> >> kHz!). Just preparing my H bridge VLF PA and i intend to use an old = 10 >> >> kV transformer which i got from an old furnance (to inflame the oil >> >> stream), see >> >> https://dl.dropboxusercontent.com/u/19882028/VLF/10kV%20Trafo.jpg =20 >> >> =20 >> >> Will that work on 2.4 km distance? It's well inside the near field. >> >> Which mode could be possible? QRSS-3? CW? >> >> The 2200000 m band, or 2.2 Mm band :-) A near field of 350 km !! >> >> I hope i can apply 10 kV to the antenna. It will not be resonated. A= nd >> >> maybe i will see harmonics as well, because the input is rectangular= .... >> >> =20 >> >> 73, Stefan/DK7FC >> >> =20 >> --------------010906090509080701020904 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by smtpa.mediabeam.com id s9AAF28M005068
Hi Stefan,

interesting stuff! Keep in mind these oil burner ignition transformers are designed to feed a spark with high ignition but low burning voltage - nearly short circuit. So they have a large stray inductance and resistance and a current limiting characteristc. Furthermore they are only suitable for intermittend service (33% within 3 minutes as you see from the label) and the middle of the secondary is usually connected to the case. I used 6 of them in parallel for feeding a tesla-transformer built by students during my former job at FH Amberg. But you shold try it anyway.

Nice your high power capacitor battery - reminds me to an own project during my promotion at TU Braunschweig in the 70s of last century ;-). Our institute made R+D on arcs and sparks and built a synthetic switch testing facility for medium voltage vacuum switches. Before breaking an LC circuit made a current of 50 kA for two halfwaves of 50 Hz and after breaking there was a recovering voltage abot 60 kV at some kHz. Dont know the components data anymore but there was a lot of stored energy and we had to develop special fuses for each capacitor to avoid explosions in case of a component failure. At that time I devloped the central electronic control unit for the whole testing site - some severe emc problems had to be solved successfully! Later on the had a lot of trouble substituting all those large PCB filled capacitors ...=C2=A0 Verdammt lang her, verdammt lang her!

Wishing you good results with your test!

73,
Tom, DK1IS
www.qrz.com/db/dk1is


Am 09.10.2014 22:57, schrieb DK7FC:
Hi Markus,

Thanks for the calculations. We will see the results.
I do take care. In my promotion project at TU Darmstadt i daily worked with a capacitor battery having 15 kV / 12000 uF, see an image showing 1/3 of the battery at https://dl.dropboxusercontent.com/u/19882028/IMG_8073.JPG Would be fine for a tube PA ! :-)

Once again the PA has some EMC problems and i cannot run the full power. Hope to fix that tonite...

73, Stefan


Am 09.10.2014 18:35, schrieb Markus Vester:
Stefan,
=C2=A0
this could work.=C2=A0In the capacitive near-field range, the electrical field would be
=C2=A0
=C2=A0E =3D voltage * capacitance=C2=A0* effective height=C2=A0/ (2 pi ep= silon0) / distance ^3
=C2=A0
With 10 kV on your antenna capacitance and height,=C2=A0you'd get=C2=A0about 0.15 mV/m at 2.4 km, maybe=C2=A014 dB stronger than=C2=A0ZEVS.
=C2=A0
Take care!=C2=A0T= ouching 10 kV on 136 kHz=C2=A0will severly burn you. But on 136 Hz=C2=A0it would kill you, unl= ess the current is safely limited to a few mA.=C2=A0
=C2=A0
73, Markus


-----Urspr=C3=BCngliche Mitteilung-----
Von: DK7FC <73dk7fc@googlemail= ..com>
An: rsgb_lf_group <rsgb_lf_grou= p@blacksheep.org>
Verschickt: Do, 9 Okt 2014 2:51 pm
Betreff: LF: ELF communications ?




Hi ELF,=20

 =20

 This afternoon i'm attempting to transmit on my INV-L on 136.172 Hz (not=
 =20

 kHz!). Just preparing my H bridge VLF PA and i intend to use an old 10 =20

 kV transformer which i got from an old furnance (to inflame the oil =20

 stream), see =20

 https://dl.dropboxuserco=
ntent.com/u/19882028/VLF/10kV%20Trafo.jpg=20

 =20

 Will that work on 2.4 km distance? It's well inside the near field. =20

 Which mode could be possible? QRSS-3? CW?=20

 The 2200000 m band, or 2.2 Mm band :-) A near field of 350 km !!=20

 I hope i can apply 10 kV to the antenna. It will not be resonated. And =20

 maybe i will see harmonics as well, because the input is rectangular...=20

 =20

 73, Stefan/DK7FC=20

 =20

--------------010906090509080701020904--