Return-Path: Received: from mtain-da08.r1000.mx.aol.com (mtain-da08.r1000.mx.aol.com [172.29.64.80]) by air-dc03.mail.aol.com (v129.4) with ESMTP id MAILINDC032-86274c7e7c3f125; Wed, 01 Sep 2010 12:15:59 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-da08.r1000.mx.aol.com (Internet Inbound) with ESMTP id 48C5438000090; Wed, 1 Sep 2010 12:15:57 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Oqpwx-0003UM-8x for rs_out_1@blacksheep.org; Wed, 01 Sep 2010 17:14:11 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Oqpww-0003UD-Ow for rsgb_lf_group@blacksheep.org; Wed, 01 Sep 2010 17:14:10 +0100 Received: from out1.ip07ir2.opaltelecom.net ([62.24.128.243]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Oqpwr-0001Q8-FE for rsgb_lf_group@blacksheep.org; Wed, 01 Sep 2010 17:14:10 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Av0EAKcYfkxcEY6J/2dsb2JhbACPXQORAHG/HYU5BIFXi0s X-IronPort-AV: E=Sophos;i="4.56,304,1280703600"; d="scan'208,217";a="459337548" Received: from unknown (HELO xphd97xgq27nyf) ([92.17.142.137]) by out1.ip07ir2.opaltelecom.net with SMTP; 01 Sep 2010 17:13:57 +0100 Message-ID: <002501cb49f0$acabccb0$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <000a01cb493d$fb8f3410$0401a8c0@xphd97xgq27nyf><4C7E2046.536.2C4F91@v.d.heide.on-line.de> Date: Wed, 1 Sep 2010 17:13:53 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001 Subject: Re: LF: VLF THOUGHT Content-Type: multipart/alternative; boundary="----=_NextPart_000_0022_01CB49F9.0DF697E0" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE autolearn=no version=2.63 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-aol-global-disposition: G x-aol-sid: 3039ac1d40504c7e7c3c5c8e X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none ------=_NextPart_000_0022_01CB49F9.0DF697E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable With all the energy concentrated into a single tone on 8.97 Kcs it co= uld well travel a considerable distance with a few Kilowatts of audio= beamed in an arranged direction, especially along a valley. I am surprised that the high voltage 50 Hz electricity overhead distri= bution network is not heard over great distances by ear. g3kev =20 ----- Original Message -----=20 From: Warren Ziegler=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Wednesday, September 01, 2010 3:31 PM Subject: Re: LF: VLF THOUGHT Rik, Krakatoa exploded with the equivalent force of 200 Megatons of TN= T, bigger than the largest Hydrogen bomb and 13,000 times the size of= the nuclear explosion that destroyed Hiroshima. That said, I believe that what was hear at a distance was still= the low frequency rumble, 100Hz is attenuated at only 0.3dB/km while= 10kHz is attenuated over 150dB/km. Best to stick with EM waves as opposed to sound. -=20 73 Warren K2ORS WD2XGJ=20 WD2XSH/23 WE2XEB/2 WE2XGR/1 On Wed, Sep 1, 2010 at 3:58 AM, Rik Strobbe wrote: All, here some real "DX":The explosion of the Krakatoa (1883) was heard= in Perth (Australia), 3100 km away, and on the island of Rodrigues,= 5000 km away. 73, Rik ON7YD ________________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@black= sheep.org] namens Klaus von der Heide [v.d.heide@on-line.de] Verzonden: woensdag 1 september 2010 9:43 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: VLF THOUGHT Hello All, two years ago someone disturbed my breakfast by a deeply hammering disco sound. So I took my car to search for the source. Surprisingly, the sound decreased to nearly zero when I drove some kilometers in that direction where the sound seem to come from. The Odyssey took 45 minutes. But finally I found the open-air disco 20 km from my home in a lonely wood. Indeed, the sound took nearly 60 seconds from there to my home. That's more than a thunder usually reaches. More than thousand square-kilometers where contaminated, including 23 protected nature resevats. Yes we can, but Mankind should not do everything what it can. 73! Klaus, DJ5HG - =20 ------=_NextPart_000_0022_01CB49F9.0DF697E0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
With all the energy concentrated into= a single tone=20 on 8.97 Kcs  it could well travel a considerable distance wi= th a few=20 Kilowatts of audio beamed in an arranged direction, especial= ly along a=20 valley.
I am surprised that the high voltage= 50 Hz=20 electricity overhead distribution network is not heard over great= distances=20 by ear.
 
g3kev
 
----- Original Message -----
From:=20 Warren= Ziegler=20
Sent: Wednesday, September 01= , 2010 3:31=20 PM
Subject: Re: LF: VLF THOUGHT<= /DIV>

Rik,

   Krakatoa exploded with the equivalent force of 200= Megatons=20 of TNT, bigger than the largest Hydrogen bomb and 13,000 times the= size of the=20 nuclear explosion that destroyed Hiroshima.
 
   That said, I believe that what was hear at a dista= nce was=20 still the low frequency rumble, 100Hz is attenuated at only 0.3dB/km= while=20 10kHz is attenuated over 150dB/km.

Best to stick with EM waves as opposed to sound.

- 
73 Warren K2ORS
         = ;  =20     WD2XGJ 
          &nb= sp;  =20   WD2XSH/23
             =  =20 WE2XEB/2
               = =20 WE2XGR/1

On Wed, Sep 1, 2010 at 3:58 AM, Rik Strobbe= <Rik.Strobbe@fys.kuleuven.be>=20 wrote:
All,

here= =20 some real "DX":The explosion of the Krakatoa (1883) was heard in= Perth=20  (Australia), 3100 km away, and on the island of Rodrigues,= 5000 km=20 away.

73, Rik=20  ON7YD
________________________________________
Van: owner-rsgb_l= f_group@blacksheep.org=20 [owner= -rsgb_lf_group@blacksheep.org]=20 namens Klaus von der Heide [v.d.heide@on-line.de]
Verzonden:=20 woensdag 1 september 2010 9:43
Aan: rsgb_lf_group@blacksheep.org
Onderwe= rp:=20 Re: LF: VLF THOUGHT

Hello All,


two years ago someone di= sturbed my=20 breakfast by a deeply
hammering disco sound. So I took my car= to search=20 for
the source. Surprisingly, the sound decreased to nearly
= zero when=20 I drove some kilometers in that direction where
the sound seem= to come=20 from. The Odyssey took 45 minutes.
But finally I found the open= -air disco=20 20 km from my home
in a lonely wood.

Indeed, the sound= took nearly=20 60 seconds from there to my
home. That's more than a thunder us= ually=20 reaches.

More than thousand square-kilometers where=20 contaminated,
including 23 protected nature resevats.

Ye= s we can,=20 but Mankind should not do everything what it=20 can.


73!

Klaus,=20 DJ5HG



= -
 
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