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To: Alan Ibbetson <alan@g3xaq.demon.co.uk>, <rsgb_lf_group@blacksheep.org>, <colin@g3psm.net>
From: John W Gould <jwgould@iee.org.uk>
Date: Thu, 24 May 2007 11:35:14 GMT
Message-ID: <Zen-1HrBb9-0000NV-1D@pythagoras.zen.co.uk>
Subject: Re: LF: RE: 500kHz Distance
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Alan, thanks for your comments appreciating the work that has gone on these past years to get to this position.  As I said in my reply to Laurence it's very much a team effort as you appreciate, with thanks to Colin and also RSGB HQ.

Noted your comments re power.  

Your less of a novice that I as you are at least on the band!

73 John, G3WKL

Alan Ibbetson <alan@g3xaq.demon.co.uk> wrote :

> John,
> 
> I think your group has done a fantastic job getting UK amateurs the 
> first general operating permits for 500K in Europe.
> 
> I'm interested in aerial experiments but, to make this offer some 
> returns on the effort, I would favour a power limit at the aerial input, 
> as we have on the higher bands. That way I will be motivated to make my 
> electrically small aerial as efficient as possible within its domestic 
> setting.
> 
> I don't really mind what that power limit is. Although 20W or more might 
> be nice for DXing, it doesn't seem necessary for inter-UK contacts. I 
> would be happy with 4 or 5W, which is what most people seem to be 
> running. Once other countries gain access to the band I think there will 
> be stronger case for higher power.
> 
> I'm a newcomer to the band, so treat these comments as "from a novice".
> 
> 73,
> 
> Alan G3XAQ
> 
> In message ,&amp;lang=en">Zen-1HqyLJ-0000Zb-HL@heisenberg.zen.co.uk>,
> John W Gould 
> &amp;lang=en">jwgould@iee.org.uk>
> writes
> >Thought that I had better respond to Laurie's e-mail, now a few days ago.
> >
> >This is because the matter of the power level is to an extent under 
> >review by Ofcom.  If you recall we, RSGB, asked back in 2004 for a 1W 
> >ERP limit as that was consistent with experience at 136kHz.  A ERP 
> >limit also gives Ofcom a real view as to what the likely coverage would 
> >be at any particular bandwidth.  That we were offered -10dBW ERP 
> >reflects both a bold step by Ofcom and also some caution, given that 
> >they have to an extent taken an interesting view of ITU Radio 
> >Regulation 5.58 to our benefit.  RR 5.58 defines 500kHz as an 
> >international distress and calling frequency for Morse radiotelegraphy. 
> >Ofcom may have taken the decision as they may expect to be withdrawn at 
> >WRC07, and on knowledge that in this part of the world 500kHz is no 
> >longer used as an international distress calling frequency.  Other 
> >authorities have not been so minded, as Dick, PA0SE, recently 
> >discovered; they prefer to wait until such time as RR 5.58 has been
> deleted.
> >
> >Whilst we are currently limited to -10dBW RSGB/Ofcom are keeping the 
> >matter under review and it may be timely, now that we have a good body 
> >of experience to request that the limit be reconsidered.  As far as I 
> >am aware no interference complaints, or even local RFI problems have 
> >been received, and our operating and conformance to licencing 
> >conditions have been exemplary.  From comments on this group it may be 
> >better to request say a 10 or 20W power limit at the aerial feed-point, 
> >for reasons mentioned by Laurie.  Whatever change to the limit is 
> >agreed, if indeed any in the near term, it will have to be a cautious 
> >change until such time as the Radio Regulations are more helpful in 
> >allowing administrations to consider proper secondary allocation to the 
> >Amateur service.  This may or may not happen for a while, as we are 
> >only really working at present to get the matter firmly on the WRC2011 
> >agenda, such is the speed of the ITU.  There is good practical reason 
> >for making a request of this nature as one of the reasons why the ITU 
> >process seems so slow is that for normal protocol to be followed one 
> >needs to have had technical studies completed that relate to the new 
> >proposals for the part of the spectrum in question.  Our activity 
> >between 502 and 504kHz, along with that by the US, Germany and Sweden 
> >may qualify as such a study, so continuing the experiments at a higher 
> >power, with the added challenge of maximising ERP from a fixed 
> >feed-point power limit would add some breadth to our work.
> >
> >Of course, the unexpected could always happen, and we get something 
> >sooner in the margins of Agenda Item 1.14 at this year's WRC.  However, 
> >as Agenda Item 1.14 is to review the operational procedures and 
> >requirements for GMDSS and other related provisions our chances are 
> >slim, as the Maritime service is likely to want to reuse the frequency 
> >around 500kHz.  However, it is an agenda item concerning this part of 
> >the spectrum so the possibility, however distant, must be there.
> >
> >I'd be interested in any further views to Laurie's proposal; I'am open 
> >to suggestions as to the power level, but it will be important to hit a 
> >target that is both challenging to the experimenter, helpful for 
> >continued propagation research and also one that will not provide too 
> >much risk for Ofcom in terms of coordination with the primary user service.
> >
> >73 John, G3WKL
> >RSGB HF Manager
> >IARU Region 1 LF Coordinator
> >
> >
> >
> >
> >
> >
> 
> -- 
> 
> Cheers,
> 
> Alan G3XAQ
> alan@g3xaq.demon.co.uk