[cma-l] Signal Strength

Fri May 21 17:11:21 BST 2010

Hi Alan

Signal strength is a difficult thing to determine and is not of course directly related to propagated ERP.

CR stations have to put up with lower signal strengths than commercial broadcasters and generally thst isn't a problem.

It would be very difficult to plan a level of ERP that a CR would have to have for instance 64dbuV/m throughout its desired coverage area and there are many constraints involved which anyone who has had to wait the usual 4 months to get a frequency cleared and has asked why will know.

CRs don't get a blanket 25W - many have more and some have a great deal more, as looking them up on Ofcom's TX Parameters list will reveal.

The process is "tell us what area you wish to cover and how you propose doing it and if we license you we'll do our best to give you the power you need".

Ian Hickling

Partner

transplan UK

From: alan.coote at btinternet.com
To: transplanfm at hotmail.com; cma-l at commedia.org.uk
CC: philipfurnivall at aol.com; neal at nealuk.com; robert.pobjoy at hexwebs.co.uk; keepitlampy at googlemail.com
Subject: RE: Signal Strength
Date: Fri, 21 May 2010 14:25:00 +0100

Hi Ian,

I agree that 75dBuV/m is more than enough for modern receivers, after all the standards were drawn up in the 60s. Also 66dBuV/m is a good working signal strength however many CRs (including mine) do not achieve that. 

My Point is that it is incorrect to give blanket ERP of 25W is to each CR. Who is to say that in an extreme case 570W isn’t right for a station with challenging a environment.  

The analogy is, if you’re trying to hear a conversation with other people shouting in the room, then everyone must shout to be heard. The BBC and early Commercial stations were given very generous TX power and channel  spacing. Hence it is very difficult for the whispers of CR to be heard in crowd. 

It is logical therefore to increase CR TX allowances to compensate. A downside may be some adjacent channel interference in marginal areas, but that is no worst than now and allows better penetration in licensed coverage areas.  

Alan

From: Ian Hickling [mailto:transplanfm at hotmail.com] 
Sent: 20 May 2010 8:21 AM
To: alan.coote at btinternet.com; cma-l
Cc: Philip Furnivall; neal; robert.pobjoy; Doug Stewart-Hale
Subject: Signal Strength

Alan
This isn't going to happen unfortunately, because CR stations inherently serve different-sized areas and terrains.
Also, signal strength, measured in dBuV/m is a function of where the receiver is - not the source ERP.
48dBuV/m in our experience is perfectly adequate for resolved mono and 64 for good stereo.
Raising the standard for stereo to 75 would require a nominal factor of 11,7 increase in transmitter power - taking the usual 50W to 570W.
Not I suggest within the scope of most existing transmitters - and certainly not within Ofcom's brief or current mind-set!
The solution is better attention to the present FM spectrum - and if course the full complete and efficient eradication of all illegal broadcasters.
Both an essential part of Ofcom's practical brief in my view.
Ian H

From: alan.coote at btinternet.com
To: transplanfm at hotmail.com; jaqui.devereux at commedia.org.uk
CC: cma-l at commedia.org.uk
Subject: RE: [cma-l] CMA Proposals for Jeremy Hunt - Secretary of State for Culture, Olympics, Media and Sport
Date: Wed, 19 May 2010 00:24:08 +0100

I agree with Ian, on the Pirate radio issue and add;

I know that Ofcom have an obligation to tackle pirate radio and actively do so where practical.  The issue of community radio’s limited ability to combat pirate radio is down to the paltry transmitter power and therefore signal strength. 

We should insisted that ALL community radio stations are permitted to increase their signal field strength to 75uV – the ITU standard. Currently, most if not all are significantly less than this and therefore very susceptible to interference and poor penetration in urban areas. 

The key advantages are that nearly all station will be able make this change at no cost and increase their viability through better audience reach, while not effective legitimate broadcaster.  Surely this is a no brainer? 

Regards

Alan

Alan Coote
Managing Director 
The Bay Radio
Office 01202 580200
Studio 01202 571028
Mobile 07801 518858

Email alan.coote at thebayradio.com
Web www.thebayradio.com      

From: cma-l-bounces at mailman.commedia.org.uk [mailto:cma-l-bounces at mailman.commedia.org.uk] On Behalf Of Ian Hickling
Sent: 12 May 2010 9:19 PM
To: Jaqui Devereux
Cc: cma-l
Subject: [cma-l] CMA Proposals for Jeremy Hunt - Secretary of State for Culture, Olympics, Media and Sport

Yes, Jaqui, there is.
My quoted extract from your response below is not strong enough by a long way.
Ofcom will never countenance allocating more power to Community Radio licensees in order to fight pirate radio interference.
That's working backwards.
What it can do, and indeed should do, but what it won't do without the motivation empowerment and funding from Government is to actively and effectively eradicate pirate radio and positively source usable FM channels for new Community Radio stations in every location where there is a demand - rather than shut the door on applications before it has done its homework.

That's what you should be asking - nay - demanding.

Ian Hickling
Partner
transplan UK

> Date: Wed, 12 May 2010 19:47:08 +0100
> From: jaqui.devereux at commedia.org.uk
> To: transplanfm at hotmail.com
> CC: cma-l at commedia.org.uk
> Subject: Re: [cma-l] Jeremy Hunt MP confirmed as Secretary of State for Culture, 
> Olympics, Media and Sport
> 
> Arguing to ensure that the growth of community media (radio, TV and
> internet based projects) is recognised, valued and funded in
> appropriate ways, through appropriate funding and spectrum allocation
> policies (including power transmission issues for those of you
> fighting pirate radio)
> 
> Let us know if we have missed anything you would like us to put forward.
> 
> Best wishes
> 
> Jaqui
> 
> Director, Community Media Association
>  		 	   		  
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