1. Introduction & Foreword
2. Issues to Note
3. Solutions
1. Solution #1 – 88MHz
2. Solution #2 Using 99.8 (2BR becomes 100.1)
3. Solution #3 Using 99.8 / 99.9 (2BR becomes 102.2 or 102.1)
4. Solution #4 94.6 Making use of the Holme Moss / Emley Moor transmitter
4. Conclusion
5. Further Information and Clarification
6. Getting these changes made a reality
7. Appendix
8. References & Bibliography

1 Introduction & Foreword
This document is based on an initial idea and frequency planning thoughts from Dr Paul Groves, to whom we are most grateful. A simplified version of this document and some of Dr Groves’ frequency planning ideas can be found on his new web site Frequency Finder UK located at : - http://mysite.freeserve.com/freq_find/index.html).

The idea revolves around creating a new frequency for West / South Yorkshire. In order to create a new frequency a gap must be first sought and therefore other services currently available juggled to make better use of the spectrum. This document uses the frequency listing in the appendix as a platform. Is can be seen the spectrum in this part of the country is very packed. This frequency list encompasses both the BBC and Independent broadcasters technical parameters and pixel plots have been carried out by using a program named Radio Mobile.

The area of interest is based in Northern England and is highly populated, with the major towns of Manchester, Leeds, Sheffield and Huddersfield in cross proximity to the area of interest. It is common for cities to have a large number of independent radio stations, which makes space quite sparse. Hence by producing a spare frequency for this region may invoke interest from interested parties in any of these cities. It would also mean that bidding might come from a large proportion of interested parties, which makes this frequency of great financial benefit.

Figure 1- Yorkshire and the North of England. ^[1] © Microsoft World Atlas.

What should also be noted is that due to the hilly terrain this means than some distant "local" transmission are received clearly in areas of greater elevation. This also means that any frequency used here could also be picked up in the distant local area.

Holme Moss transmits no less than 3 different BBC local services from but each transmits in a different direction to reach its target audience.

These factors have to be taken into account when swapping and adjusting frequencies.

Figure 3- Holme Moss coverage for BBC Sheffield (pale orange colour) ^[2] Map © BBC.

Figure 4- Holme Moss coverage for BBC GMR (pale orange colour) ^[2] Map © BBC.

These figures are assumed to be relatively accurate as these were plotted by the BBC to show the level of coverage. As these plots are quite old, it’s possible that the coverage is understated.

The new service could either use Holme Moss or Emley Moor – using a power in the region of 5kW; the service could aim for the reception produced by amalgamating the BBC Leeds and BBC Sheffield coverage areas (in the case of a Holme Moss service).

Using Radio Mobile and a power of 5kW the following plots are produced for coverage at Holme Moss and Emley Moor (the two most likely transmitters for a new service).

Figure 5 – 5kW from Holme Moss [3]

Figure 6 – 5kW of Power from Emley Moor. [3]

Since there are no complaints currently one can only assume that the current system works if is somewhat wasteful. As the region is very hilly some frequencies are re-used on either side of the Yorkshire moors – since the moors themselves act to reflect the transmissions away from the other area using the same frequency.

However, when taking into account a new service, the service available in the area must be taken into account but also number of non-Yorkshire services do spill over into Yorkshire.

Figure 7- Sutton Coldfield coverage for BBC West Midlands at 12kW ^[2] Map © BBC.

Standard Frequency planning parameters are :

• Any transmissions from the same or adjacent (geographically) transmitters must have at minimum a 400kHz separation.
• At absolute minimum transmissions of the same services but from adjacent (geographical) transmitters could have a channel separation of 304kHz as was proved by the BBC’s 1996 research on an In fill transmitter for London at Crystal Palace. The report is entitled "The Crystal Palace FM filler experiment" and can be downloaded from [http://www.bbc.co.uk/rd/pubs/reports/1996-06.pdf]
• From 87.5 to 88MHz is typically used for RSL’s (Restricted Service Licences) covering special events – it is unlikely that any suggested frequency usage in this band will be accepted by Ofcom.
• Broadcasts in the 107 to 108MHz band are subject to a power limit due to possible interference with Air crafts and emergency services. The typically limit towards the top of the FM / VHF band is 100 Watts.
• Receiver IF’s (Intermediate Frequency’s) are typically 10.7MHz – that means any broadcasts from the same or adjacent transmitters should not be 10.7MHz apart. Interestingly though some receivers are 10.6 MHz and likewise some 10.8MHz.
• All frequencies which this report derives must be checked by Ofcom to ensure that the I.F’s of these frequencies does not fall onto the frequency of any emergency service or authorised user of the out of band region.

However it can be deduced from the Appendix that a number of transmitters share frequencies and others have a channel separation of less than 300kHz – as stated above this must work in some cases.

There are a number of small holes on the band, but none of these are really large enough to fit a service in directly. Hence a degree of frequency shuffling and reordering is necessary to create a space wide enough to fit in the extra service.

The location of the gaps are :-

• 200kHz between Holme Moss and Beecroft Hill (Leeds) – allowing for maximum deviation. However Holme Moss is the major transmitter for this area and hence this frequency is a poor choice. (This gap occurs in the BBC Nationals and Classic FM sub bands).
• A 200kHz gap between the Independent Local Radio service of 2BR from Pendle Forest running at 0.75 kW and Classic FM from Idle (Bradford) at 0.5 kW.
• A 100kHz gap between Century Radio at Bilsdale and the Classic FM main transmitter for this region at Holme Moss. (100.9MHz – however as was proved by XFM in London, a 100kHz channel separation between this broadcast and another in Sussex caused interference to both parties concerned).
• There’s also a 100kHz channel separation between Woolmoor and Acklam Wold on 104.5MHz is again too small to fit a service in.

Sutton Coldfield uses the same power for Heart (100.7) this means that these services could be safely ignored in the frequency plan.  Although the Pennines do have a lot of elevation, a local service in a valley should be immune from interference. A new service for Huddersfield (for example) would be immune to interference from Sutton Coldfield due to the Peak National Park shielding transmissions.

Looking at the nationals from Sutton Coldfield

 

Figure 8- Sutton Coldfield coverage for BBC Nationals at 240kW ^[2]Map © BBC.

Again the data is slightly old but never the less gives a good idea. It may understate due to the nature of modern receivers being far more sensitive. Note on the map the furthest that this signal theoretically reaches is Chesterfield. This is just a few miles short of Sheffield and really could not be discounted for services in South Yorkshire. For a new service in the Huddersfield area with the natural blocking due to the Peak District National Park – the weaker signal could not over come this well and hence may not be received in the Huddersfield Area.

3. Solutions

3.1 Solution #1 (88.0MHz)
The first solution actually seems rather obvious and doesn’t involve swapping or changing frequencies. As Sutton Coldfield is apparently out of range, this allows for 400kHz separation to the next nearest frequency of 88.4 from Hebden Bridge. Which as can be seen from the next image is quite important.

 

Figure 10 – the separation must be 400kHz. The Huddersfield signal also travels a long way for very little power (200W). Hebden Bridge - Yellow, Huddersfield – Purple. [3]
(NB Sheffield is marked in the incorrect place on some maps due to a software error)

The frequency could be used for an ILR for Huddersfield (for example) which could go here (400kHz separation) – even though the Hebden Bridge mast is close, or alternatively any service as this would not suffer interference from Sutton Coldfield. So long as the mast used is not in the yellow area of figure 7 (as the channel separation is only 300kHz and is not enough!).

The transmitter at Huddersfield is at Ainley Top and is an ILR transmitter so, there would be no great problem with broadcasts from here using 88 also noting the presence of Hebden Bridge – only 25W but still important.

The intermediate Frequency of this is 98.7 (100kHz from Bilsdale BBC Radio 1 – but Bilsdale is too far away from the new service for it to cause any difficulties) and 109.4 (out of band).

On the face of it this is the only obvious gap to fit in a service, however by taking into account the power and locations of some of the transmitters in this area it may be possible to shoe horn in another service. It may also be potent to reduce the channel separation between the BBC services in order to make space further up the band. It may well be necessary to adjust the frequencies slightly of some of the current services as there are gaps in the band but not largest for a service.

However one advantage for the frequency planner, the Peak District National Park may well shield broadcasts from one side of Yorkshire to the other and Lancashire. It is from these details that some frequency re-arranging can be carried out in order to add in an extra service.

88MHz appears to be the best solution – and this could even work for a service (regional) from Holme Moss or Emley Moor producing better coverage for the new service but without causing a detrimental effect on current services. Note Ofcom rules also apply to 87.6 to 88.0 where these frequencies are used for Short Term (time wise) or small distance licences known as Restricted Service Licences (RSLs).

3.2 Solution #2 Using 99.8 (2BR becomes 100.1)
Making use of a little frequency re-shuffling it is possible to use 99.8. This is how - there is a gap between the ILR services of 2BR and Classic FM, but in terms of transmitters the two coverage areas do not overlap. Therefore the current channel separation can be decreased making better use of the band. This now leaves a gap – where 2BR was, for a new service to occupy. This service could be from Manchester where it is unlikely that signals transfer to far out.

Figure 12 – Shows Pendle Forest Yellow and Idle Blue. However, Burnley (2BR’s target area) is covered [3]

The coverage only overlaps in a few areas (marked green), for the national Classic fm station this may not be seen as a problem. Allowing for 2BR to be moved to 100.1 is within 200kHz of Classic FM to from Idle  on 100.3 (this giving 10.8 clearance to BBC R2 on 89.3 – which is the service from Holme Moss) could case some adjacent channel interference problems especially for listeners using receivers with poor selectivity.    Pendle Forest, however, carries BBC R2 – indicating that the reception of this signal in the Burnley area is poor – hence the interference may be minimal in Burnley but problematical towards the Northern reaches of the 2BR area.

It must also be considered that with 2BR on 100.1 there could be interference to Smooth on 100.4 and vice versa due to the resulting 300kHz relationship . The service which goes into the gap left by 2BR can only be a local based service from a transmitter which carries the BBC nationals (indicating that the signal from Holme Moss is poor in this area – where there 10.7 clearance to BBC R2).  Hence this option is limited in its scope.

3.3 Solution #3 Using 99.8 / 99.9 (2BR becomes 102.2)

Figure 14 – the Burnley signal v Belmont signal. [3]

Another option is in making 2BR 102.2, as the Belmont signal (6.4kW) of Lincs FM has minimal effect. 2BR would need to be 102.2, moving Galaxy down 100kHz closer to the low powered Sheffield mast (the Galaxy mast is an infill for Manchester), this would resolve things if there were a problem. Note I say IF, this is because Ofcom has allocated a new frequency on 97.7 in Manchester, 100kHz away from BBC Radio 1 from Pendle Forest – this means that the interference is minimal and hence 2BR does not necessarily need to be moved. If the signal strength of Galaxy is at least 7dB higher in Galaxy’s coverage area then there is not a problem.

Adding in Wigan’s Wish FM, shows some problems,

 

Figure 15 – Belmont (Yellow) v Burnley (Purple) v Wigan (blue). [3] If this is a problem for Wish (even though it is outside of their coverage area), then a new frequency can be sought (this is quite easy due to Wish’s small coverage area) – there is no interaction with Bradford.

This gives the required 400kHz to Woolmoor (the semi-transparent area) – as 2BR is now at 102.2 – making 102.1 makes life easier (as it is not an intermediate frequency of Radio 3). Ideal for a service from the Leeds or Bradford area. The new service should be given either 99.8 or 99.9 (it must be transmitter, which repeats the nationals from Holme Moss).

Figure 16 – Looking at 101.7 to 102.4 on the VHF band – using data from [4] & [5] – and taking into account the moving of 2BR.

Checking for Intermediate Frequency issues on these transmissions,

2BR would have an Intermediate Frequency of 91.5 since this lands right on the main Holme Moss transmitter of Radio 3, so it could be 102.1- 102.3 would not work as this is too close to the Halifax transmissions of Pulse at 102.5.The other IF is at 112.9. Galaxy is the same as previously – so if any complaints regarding IF are not due to changes made by this document!

Again 99.8 can be used for service from a transmitter which is also used for providing coverage of the BBC Nationals.

3.4 Solution #4 94.6 Making use of Holme Moss / Emley Moor transmitter
In order to broadcast a new regional service, the transmitter at either Winter Hill or Holme Moss should be used due to its prime location and excellent coverage.

By making use of the space at the top of the band due to the fact that the Sutton Coldfield transmission do not reach the target area and by some juggling of the current frequencies in particular the nationals this will allow for a new frequency to appear. This can be used for regional broadcasting – hence this licence is worth a great deal more and is of much more use to all parties concerned.

Referring to the Introduction, 5kW from Holme Moss and Emley Moor will travel a great distance. Either of these transmitters has a great advantage with its coverage of Manchester, Leeds, and Sheffield and perhaps on a good day even Liverpool!

 

 

By making this change creates a gap at 94.6MHz. This frequency is shared with BBC Stoke (from Alsagers Bank).

It is therefore unlikely that transmission would travel this far North (and if so could be limited a little), clearly transmissions South from Holme Moss would also be limited be the use of directional transmitters. (Coverage patterns such as that of figure 2 or figure 3 – would probably be the most potent).

It is also 100kHz to Chesterfield. Referring to page 5, this means that this is moved to either 88 or 88.1 (where there is a gap), or 99.9 (which as proved before is also a gap). There is a relay for each of the national stations at Chesterfield indicating coverage of the Holme Moss transmitter is poor.

Chesterfield does not have a large coverage area so it is possible for it to co-exist with another station the other side of the Pennines.

Giving Chesterfield 88.0MHz, Pendle Forest 88.2MHz and with Sutton Coldfield unchanged on 88.3MHz, produces the following plot.

 

Figure 21 – Shows areas of red (interference) where they are least wanted - in Chesterfield! [3]    This is allowing 300kHz from Sutton Coldfield to Chesterfield. Chesterfield 400W Yellow, Pendle Forest 1kW Blue, Sutton Coldfield Purple, 250kW. However 300kHz between Chesterfield and Sutton Coldfield is plenty.

This is not necessarily, the best solution, but the Pendle Forest, Chesterfield issue shows there is little or no interference between these too, Woolmoor co-exists with Sheffield so clearly the 99.9 option is best (allowing 400kHz to Idle (Bradford)). These are well screened by hills – this is OK!!

Figure 22 – Chesterfield - Purple, Idle – Yellow, Pendle Forest – Blue. [3]

With 400kHz clearance this would work in reality a 100kHz clearance between Idle and Chesterfield would be enough – these are well screened by hills.

Figure 23 – The new home for BBC Sheffield at Chesterfield is 99.9. [4] & [5]

Figure 24 – BBC Lincolnshire 94.9, 6kW, Yellow. BBC Stoke 94.6 Alsagers Bank – Blue. The new service on 94.6MHz must transmit North and East from Holme Moss or Winter Hill.  Its coverage area could possibly include Bradford or Hebden Bridge or Huddersfield. [3]

The coverage areas would not overlap with the new 5kW service – if they do there must be a 7dB difference between services.

Figure 25 – shows the area where the new service would go. [4] & [5]

4. Conclusion
A new service for the Yorkshire area is only possible if the current configurations are adjusted. By making use of space at thebottom of the band a service can be placed at 88MHz or alternatively a service taken from within the band to this region leaving a space in the band for the new service.

Unfortunately due to the hilly terrain this makes frequency planning quite difficult. The 250kW Holme Moss transmitter can be stumbling block with I.F. problems until it is realised that in-fill transmitters are only used where the coverage of the main transmitter is poor. Hence in these areas a frequency which has an IF that is the same or close to the value of the main Holme Moss transmitter can be used.

• A low powered ILR can be operated from any transmitter – as long as it is not in the indicated area of figure 7 – this means any transmitter can be used. It is possible for a Holme Moss or Emley Moor local service at low power.
• By moving 2BR to 100.1, a small gap is present where 2BR was moved from – this can allow a service to operate on a transmitter which also operates a BBC in-fill service. This is quite limited due to the possible interference to smooth on 100.4.
• Moving 2BR to 102.1, again allows the use of 99.8 and is prhaps the better solution offered here.
• All of the services above revolve around the use of locals service – for a regional service – the basis of this document then a frequency such as 94.6 is required, BBC Sheffield requires moving to 99.9.  With BBC Stoke being available across many parts of the North-West, then broadcasting may be possible on 94.6 from very directional aerials from Emley Moor to the North and East.  With the height advantage offered by the Emley Moor (or Holme Moss) site, and given a power of up to 5kW the service could be considered to be a regional one to the North and North-East of the transmitter site.
  

5. Getting these changes made a reality
Since the Radio Authority has been merged into Ofcom (January 2004), and now the new body has found its feet again it will be possible to forward opinions especially as Ofcom is attempting to find out more about what the people really think about their plans, and openly encourage participation.

6. Appendix
Contained with this document is a frequency listing showing the frequency holders, their powers and locations. Click here to download and view the spreadsheet.

7. References & Bibliography
The following sources have been used for information regarding this design idea;

• 1 - The maps are © Microsoft World Atlas 1998 Edition

• 2 - Mike Brown’s web site at www.mb21.co.uk, which has assisted with great pictures of the U.K transmitters and detailed transmitter coverage maps from BBC archives,

• 3 – Radio Mobile for Windows is an excellent pixel plotting software package and is also freeware!

• 4 - http://www.bbc.co.uk/reception/rpb/england.shtml – A list of all of the BBC VHF / FM transmitters, there locations and powers

• 5 – www.ofcom.org.uk – where a downloadable spreadsheet file contains all of the technical data (parameters) on MF, VHF and DAB broadcasts.

• Dr Paul Groves web site contains a wealth of information, and it also includes a simplified version of this frequency plan amongst others – well worth a visit. http://mysite.freeserve.com/freq_find/index.html