Return-Path: Received: from mtain-mg12.r1000.mx.aol.com (mtain-mg12.r1000.mx.aol.com [172.29.96.212]) by air-mf06.mail.aol.com (v129.4) with ESMTP id MAILINMF064-8bf04ced49e1be; Wed, 24 Nov 2010 12:22:41 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg12.r1000.mx.aol.com (Internet Inbound) with ESMTP id B825C38000184; Wed, 24 Nov 2010 12:22:37 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PLJ25-0007hG-5Y for rs_out_1@blacksheep.org; Wed, 24 Nov 2010 17:21:25 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PLJ24-0007h7-Fy for rsgb_lf_group@blacksheep.org; Wed, 24 Nov 2010 17:21:24 +0000 Received: from mail-wy0-f171.google.com ([74.125.82.171]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PLJ22-0006cq-Ac for rsgb_lf_group@blacksheep.org; Wed, 24 Nov 2010 17:21:24 +0000 Received: by wyb38 with SMTP id 38so2804393wyb.16 for ; Wed, 24 Nov 2010 09:21:16 -0800 (PST) Received: by 10.227.157.79 with SMTP id a15mr9791715wbx.208.1290619274882; Wed, 24 Nov 2010 09:21:14 -0800 (PST) Received: from Win7Pro (5e0728f8.bb.sky.com [94.7.40.248]) by mx.google.com with ESMTPS id i19sm5089916wbe.23.2010.11.24.09.21.12 (version=SSLv3 cipher=RC4-MD5); Wed, 24 Nov 2010 09:21:13 -0800 (PST) From: Terry GW0EZY To: References: <861077.53684.qm@web28512.mail.ukl.yahoo.com> <863803.39905.qm@web28510.mail.ukl.yahoo.com> <001701cb8aec$6dd12890$0301a8c0@your91hoehfy9g> <4CEBEEEA.5050403@iup.uni-heidelberg.de> <001701cb8bb4$1088b540$0301a8c0@your91hoehfy9g> In-Reply-To: Date: Wed, 24 Nov 2010 17:21:11 -0000 Message-ID: <000001cb8bfb$fe8a26b0$fb9e7410$@com> MIME-Version: 1.0 X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: AcuLwpzAaOKGvOtTSSSjndys3DvBGAAC7Zyw Content-Language: en-gb X-Spam-Score: 0.9 (/) X-Spam-Report: autolearn=disabled,DNS_FROM_RFC_WHOIS=0.879,HTML_MESSAGE=0.001 Subject: RE: LF: Re: VLF Transmissions Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01CB8BFB.FE8A26B0" 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_40_50,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: 3039ac1d60d44ced49dd3917 X-AOL-IP: 195.171.43.25 ------=_NextPart_000_0001_01CB8BFB.FE8A26B0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Sorry for the regulatory jargon below but for interest/information, so= me relevant agenda items at the next WRC 2012 (all publicly available= information from the ITU and CEPT/ERO websites) =20 1.10 (safety systems for ships and ports);=20 1.16 passive systems for lightning detection in the meteorological aid= s service, including the possibility of an allocation in the frequency= range below 20 kHz 1.23 an allocation of about 15 kHz in parts of the band 415- 526.5 kHz= to the amateur service on a secondary basis =20 The CEPT Conference Preparatory Group is developing the European Commo= n Positions and Briefs for the WRC (as CEPT members the UK and German= (etc) administrations will have agreed these)=20 =20 Some extracts of CEPT positions already developed for the items above= : =20 1.10 CEPT supports the exclusive primary allocation to the MMS in the= band 495=E2=80=91505 kHz 1.16 CEPT supports a primary allocation for MetAids in the band 8.3 -1= 1.3 kHz for passive applications. 1.23 that studies have taken into account CEPT proposals under agenda= 1.10 in this frequency range; some (CEPT) administrations are of the= view that an additional allocation of 15 kHz to the amateur service= in the frequency band 415-526.5 kHz is not feasible because it would= result in unacceptable harmful interference to the stations operating= in the radiocommunication services allocated in the mentioned frequen= cy band. There is no common position yet and discussions continue. =20 Further info on 1.16: =20 Although the maximum spectral emission of cloud to ground lightning st= rikes is centred between about 5 and 20 kHz, spectrum bandwidth of lig= htning stroke can reach several megahertz. The possible operation rang= e of systems for lightning detection is determined by the used frequen= cy band. In the frequency range 5-20 kHz the sky waves propagate over= very large distances with relatively little attenuation. Thus, it is= possible to receive the emissions from the cloud to ground strokes at= thousands of kilometres from the stroke location. The optimal frequency for ATD spectral emission measurements is around= 9.766 kHz. However, the frequency 13.733 kHz is successfully used by= the existing ATD systems for measurements, with a reduction of existi= ng system performance seen at 9.766 kHz. =20 Long-range lightning detection using observations near 10 kHz has been= performed in the UK since 1939, originally with a very manpower-inten= sive system measuring the direction from which signals were received,= and then since 1987 with an automated Arrival Time Difference system= (ATD) using the time differences of signal received to derive strike= locations. Now, with modern sensor systems and communications it is= possible to monitor the radio frequency received at the sensor in rea= l time. Recent monitoring since [2004] has shown that it was not pract= ical to use the frequency 9.765625 kHz at all the sensor sites, becaus= e of powerful transmissions near 10 kHz in some locations which preven= ted the operation of the passive sensors. Thus, the current system is= operating at 13.733 kHz as noted in Fig. 1 =20 The 3 dB bandwidth of existing lightning detection systems is approxim= ately 2.5 kHz and hence an allocation of between 3 and 5 kHz bandwidth= would be required =20 Currently the spectrum below 9 kHz is not allocated to any service but= the following footnotes apply: =20 5.53 Administrations authorizing the use of frequencies below= 9 kHz shall ensure that no harmful interference is caused thereby to= the services to which the bands above 9 kHz are allocated. 5.54 Administrations conducting scientific research using frequ= encies below 9 kHz are urged to advise other administrations that may= be concerned in order that such research may be afforded all practica= ble protection from harmful interference. =20 Because of the agenda item at the next WRC. I guess administrations (a= nd Met organisations) are a bit jumpy about allowing precedents for ot= her services before a decision is taken by the WRC. The chances of a= common CEPT agreement on access conditions for amateurs before the WR= C is dreamland stuff!! If each country waited, nothing would happen.= Each administration is playing it by ear and trying to demonstrate it= is complying with the Radio Regulations =E2=80=93 however illogical= the individual conditions might appear to amateurs. =20 =20 Finally, has anyone on this forum seen proposals for a =E2=80=9CNew 50= 0 kHz network=E2=80=9D? =20 http://olivier.marsan.free.fr/N5NTW/NEW500KHZNETWORK.html =20 ------=_NextPart_000_0001_01CB8BFB.FE8A26B0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Sorry for the regulatory jargon below but for interest/informat= ion, some relevant agenda items at =C2=A0the next WRC 2012 (all public= ly available information from the ITU and CEPT/ERO websites)

 <= /p>

1.10 =C2=A0(safety systems for shi= ps and ports);

1.16 passive systems for lightning detection in the meteorological ai= ds service, including the possibility of an allocation in the frequenc= y range below 20 kHz

1.23 an allocation of about 15 kHz in parts of the band 415- 52= 6.5 kHz to the amateur service on a secondary basis<= /p>

 

The CEPT Conference Preparatory Group is de= veloping the European Common Positions and Briefs for the WRC (as CEPT= members the UK and German (etc) administrations will have agreed thes= e)

 <= /o:p>

Some extracts of CEPT= positions already developed =C2=A0for the items above:

 

1.10 CEPT supports the exclusive primar= y allocation to the MMS in the band 495=E2=80=91505 kHz

1.16 CEPT supports a primary= allocation for MetAids in the band 8.3 -11.3 kHz for passive applicat= ions.

1.23 that studies have taken into account CEPT proposals under agenda 1.= 10 in this frequency range; some (CEPT) administrations ar= e of the view that an additional alloc= ation of 15 kHz to= the amateur service in the frequency band 415-526.= 5 kHz is not feasible because it would= result in unacceptable harmful interference to the stations operating= in the radiocommunication services allocated in th= e mentioned frequency band. There is no common position yet and discus= sions continue.

 

Further info on 1.16:=

 

Although the maximum spectral= emission of cloud to ground lightning strikes is centred between abou= t 5 and 20 kHz, spectrum bandwidth of lightning stroke can reach sever= al megahertz. The possible operation range of syste= ms for lightning detection is determined by the used frequency band.= In the frequency range 5-20 kHz the sky waves propagate over very lar= ge distances with relatively little attenuation. Thus, it is possible= to receive the emissions from the cloud to ground strokes at thousand= s of kilometres from the stroke location.

The optimal frequency for ATD spectral emiss= ion measurements is around 9.766 kHz. However, the frequency 13.733 kHz is successfully= used by the existing ATD systems for measurements, with a reduction of existing system performance seen at= 9.766 kHz.

 

Long-range li= ghtning detection using observations near 10 kHz has been performed in= the UK since 1939, originally with a very manpower-intensive system= measuring the direction from which signals were received, and then si= nce 1987 with an automated Arrival Time Difference system (ATD) using= the time differences of signal received to derive strike locations.= Now, with modern sensor systems and communications it is possible to= monitor the radio frequency received at the sensor in real time. Rece= nt monitoring since [2004] has shown that it was not practical to use= the frequency 9.765625 kHz at all the sensor sites, because of= powerful transmissions near 10 kHz in some locations which prevented= the operation of the passive sensors. Thus, the current system is ope= rating at 13.733 kHz as noted in Fig. 1

 

The 3 dB bandwidth of existing lightning detecti= on systems is approximately 2.5 kHz and hence an allocation of between= 3 and 5 kHz bandwidth would be required

 

Currently the spectrum below 9 kHz is not allocated to= any service but the following footnotes apply:

<= p class=3DMsoNormal> 

5.53=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0 Administrations= authorizing the use of frequencies below 9 kHz shall ensure that no= harmful interference is caused thereby to the services to which the= bands above 9 kHz are allocated.

5.54=C2=A0=C2=A0=C2=A0=C2=A0= =C2=A0=C2=A0=C2=A0 Administrations= conducting scientific research using frequencies below 9 kHz are urge= d to advise other administrations that may be concerned in order that= such research may be afforded all practicable protection from harmful= interference.

 

Because= of the agenda item at the next WRC. I guess administrations (and Met= organisations) are a bit jumpy about allowing precedents for other se= rvices before a decision is taken by the WRC. The chances of a common= CEPT agreement on access conditions for amateurs before the WRC is dr= eamland stuff!! If each country waited, nothing would happen. Each adm= inistration is playing it by ear and trying to demonstrate it is compl= ying with the Radio Regulations =E2=80=93 however illogical the indivi= dual conditions might appear to amateurs.

 

 

Finally, has anyone on this forum seen proposals for a =E2=80= =9CNew 500 kHz network=E2=80=9D?

 

http://olivier.marsan.free.fr/N5NTW/NEW500KHZNETWORK.html<= o:p>

 

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