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</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-GB link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><a name="_MailEndCompose"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>I’m going back a bit, but I recall Longley Rice only being useful for VHF between 70Mhz - 250MHz. Either side, other models need to kick in. I also remember there being a lot of fudge factors.<o:p></o:p></span></a></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Anything that is line of sight you could always use; Free Space Loss = 20log(d km) +20log(f MHz) +32.4. Then subtract a bit for buildings and trees, and a bit if the signal path is over water or damp ground, subtract a bit more for cabling and connectors and then multiply by the antenna gain… or just use software to do it for you! <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The above is useless for AM band propagation of course. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Kind Regards</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Alan<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><a href="http://www.letstalkbusinessonline.com/"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>Hear Alan Every Week on Let’s Talk Business The UK’s Premier Radio Programme For Current and Future Entrepreneurs - Now Broadcast To 4.3 Million People </span></a><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'> <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Email - </span><a href="mailto:alan.coote@5digital.co.uk"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>alan.coote@5digital.co.uk</span></a><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Phone - 0800 949 6655<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Mobile - 07801 518858<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Twitter - </span><a href="http://www.twitter.com/TheAlanCoote"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>@TheAlanCoote</span></a><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Web - </span><a href="http://www.5digital.co.uk/"><span style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>http://www.5digital.co.uk</span></a><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><img border=0 width=200 height=71 id="Picture_x0020_2" src="cid:image001.gif@01CFD808.0E7E7420" alt="cid:image001.gif@01CE03CD.223AC920"><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>The Media Production, Broadcasting and Training Company<o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> cma-l-bounces@mailman.commedia.org.uk [mailto:cma-l-bounces@mailman.commedia.org.uk] <b>On Behalf Of </b>Two Lochs Radio<br><b>Sent:</b> 24 September 2014 11:32<br><b>To:</b> The Community Media Association Discussion List; Martin Steers<br><b>Cc:</b> Ian Hickling<br><b>Subject:</b> Re: [cma-l] Community Radio on AM<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>The only Ofcom community AM coverage plot I have happened to look at in the past simply drew a nominal 5km radius circle - despite it being over a hilly city with a river through it! <o:p></o:p></span></p><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> <o:p></o:p></span></p></div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>The Canadian CRC's LRCOV online propagation calculator covers 20 MHz to 40 GHz <span class=st>using the standard Longley Rice propagation model, but as you say analyzing the antenna propagation pattern is a prerequisite for sensible results. The standard NEC tools will cover the AM frequencies quite happily, but at such long wavelengths the effects of ground proximity and nature and nearby metalwork/support guys make it a fairly uncertain process unless you are dealing with high wires in large open fields as used by the major broadcasters.</span></span><span style='font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal><span class=st><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>Also AM propagation varies dramatically between day and night, though this is generally of concern only to wide area broadcasters, not community stations received from the surface wave unless they are interfered with at night by a far distant sky wave.</span></span><span style='font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'><br><span class=st>Alex</span></span><span style='font-family:"Calibri","sans-serif"'><o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'> <o:p></o:p></span></p></div><div><p class=MsoNormal><span class=st><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>(</span></span><span style='font-family:"Calibri","sans-serif"'>----- Original Message ----- <o:p></o:p></span></p></div><blockquote style='border:none;border-left:solid black 1.5pt;padding:0cm 0cm 0cm 4.0pt;margin-left:3.75pt;margin-top:5.0pt;margin-right:0cm;margin-bottom:5.0pt'><div><p class=MsoNormal style='background:#E4E4E4'><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a href="mailto:transplanfm@hotmail.com" title="transplanfm@hotmail.com">Ian Hickling</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>To:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> <a href="mailto:martin@martinsteers.co.uk" title="martin@martinsteers.co.uk">Martin Steers</a> ; <a href="mailto:cma-l@mailman.commedia.org.uk" title="cma-l@mailman.commedia.org.uk">The Community Media AssociationDiscussion List</a> <o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Sent:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> Tuesday, September 23, 2014 4:02 PM<o:p></o:p></span></p></div><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Subject:</span></b><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'> [cma-l] Community Radio on AM<o:p></o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p></div><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>I haven't done any real appraisals apart for the Farnborough station which manages about a 2-mile radius in daytime hours which is be barely adequate but does at least cover the core population. <o:p></o:p></span></p><div><p class=MsoNormal><span style='font-family:"Calibri","sans-serif"'>I'm not aware of any computer coverage software that will cope with MF - and of course there's the question of exactly the EMRP value - and even more indeterminate - the antenna propagation pattern.<br>I'm sure other members will have first-hand information.<o:p></o:p></span></p></div></div></blockquote></div></body></html>