Mendip DSO

The MENDIP transmitter and all its relays are about to be switched to digital.

On Wednesday 24 March 2010, BBC2 will be switched off at Mendip and its relays. Full power multiplex PSB1 will take its place. That means viewers unable to receive Mendip, and thus rely on a relay will get BBC3, BBC4, CBBC, CBeebies, BBC News 24 and BBC Parliament through an aerial for the first time, as well as BBC1 and BBC2 in digital.

Wednesday 7 April 2010, the remaining analogue channels will be switched off at Mendip and all its relays. Mendip, Bristol Ilchester Crescent and Bristol Kings Weston (which already broadcast all 6 muxs) will get full power versions of all 3 PSB and all 3 COM muxs. The remaining relays, e.g. Bath, Bruton will get PSB2 and PSB3.

So to those in the affected area, are you looking forward to the switchover? Are you ready for it? Any gripes? I have one gripe: the Bath relay only getting the 3 PSB muxs. Three or four years ago, I read somewhere on the web that was one of 120 then analogue-only relays which would get all 6 muxs at switchover (Poole and Weymouth were also listed in that group). I'd like to know who decided Bath would only get 3 PSB muxes after all, just like the smaller relays (e.g. Bruton, Crewkerne, Cerne Abbas).

Not quite!

Considering your usual attention to unnecessary detail, I thought I'd point out that it's analogue Ch61 (currently ITV1) which closes on 24/03/10 and is replaced by BBCA.

Analogue ITV1 then moves to Ch64 to replace analogue BBC Two.

The decision was taken long before DSO actually started. I live in the area served by the Selkirk main transmitter and its relays. Selkirk was the first main station to switch off analogue. It was originally proposed that the relays at Hawick, Peebles, Eyemouth and Berwick-upon-Tweed would radiate all six muxs, with the remaining sites at Bonchester Bridge, Clovenfords, Galashiels, Innerleithen, Jedburgh, Stow and Yetholm only broadcasting the public service channels. But, over a year before switchover, the thinking changed. It was decreed that no relays, other than those already broadcasting all six muxs, would have anything other than the three PSB muxes on them. There was a fair level of protest locally and MPs took up the issue. But, it was said, it was a commercial decision. Because of the hills and valleys in the Selkirk service area, almost half the viewing population actually use the relays for terrestrial TV. BTW, Berwick-upon-Tweed is now an analogue relay of Chatton and won't switch until 2012. Even more frustrating for viewers served by relays is the daft, in my view, decision to drop ITV3 and ITV4 from the PSB services, but still have ITV2 plus 1 and Channel 4 plus 1.

Yes I know that. Also at Bath relay, analogue BBC2 on channel 28 will be switched off. Analogue ITV1 which is currently on channel 25 will temporarily move to BBC2's current analogue frequency, channel 28. This is so that mux BBCA (PSB1) can begin on channel 25. I just didn't want to make my original post too long-winded.

Anyhow, I'm surprised BBCA (PSB1) is going on channel 61 at Mendip. Being the BBC mux, I thought they would put it on BBC1's analogue frequency - channel 58 at Mendip, and thus move analogue BBC1 temporarily to channel 64. I expected D3&4 (PSB2) to go on to analogue ITV1's frequency channel 61 at Mendip.

It's going to have to move again, around 2012, because Ofcom have recently decided to flog off Ch 61 and 62 too, trading them for Ch 39 and 40. To keep everything in the correct aerial groupings BBCA will be moving down to 51 I think.

http://www.ofcom.org.uk/consult/condocs/800mhz/800mhz.pdf

Isn't the lack of 6-mux relays a result of Arqiva/NGW/CrownCastleInternational deciding not to fund them as they deemed the extra cost not justified by the extra revenue they would generate for their spectrum sales to 3rd party broadcasters? (In other words - it would cost them more money than it would make - a commercial decision?)

You could argue that such a decision is due more to shortsighted legislation and/or OFCOM incompetence.

The legislation should have required OFCOM to ensure that the COM multiplexes had to be offered from every tx, using SFNs if necessary to overcome the lack of frequencies. The current arrangements are based on the geography and topology of the country as it stood 40 years ago or more, and planned around everybody getting 4 UHF services (even if they didn't all get c4 when it launched the capacity was there for it to happen).

It's a postcode lottery, and thus unacceptable. The fact that it is, in part, to allow the Government to flog of frequencies makes it even less justifiable.

Six Mux coverage ........

The original plan was to equip the all the analogue main transmitters and as many of the larger population covering relays to account for 20% of the total transmitter numbers around 200-220 in total. The ITC went as far as listing all of the proposed 200 sites. They relented following the failure of ITV Digital and when they offered the three ITVD muxes out for refranchising the language was made softer and finally Ofcom decided to allow the mux licence holders to decide without direction.

I suspect that in the master unpublished current frequency plan that allocations for the three com muxes are included should a future licensee decide to increase coverage they will do so.

I partly agree there, the Government should have at least insisted that the three COM multiplexes be transmitted from the 120 then analogue-only relays (e.g. Bath, Poole, Weymouth) earmarked for 6 multiplexes, even if the rest of the then analogue-only relays e.g. Crewkerne would only carry the 3 PSB multiplexes.


In what respect? Do you mean the fact that they're re-using the same transmitter sites and frequencies as for analogue? Are you suggesting that completely new transmitter sites should have been chosen for DTT, to provide optimum DTT coverage (i.e. 99% population coverage of all 6 muxes)? For example, in the case of the West region, should a new main mast have been built at Dundry for DTT, thereby rendering Mendip (Pen Hill north of Wells) redundant? Could one enormous mast on Dartmoor have provided 6 DTT muxes to the whole of the Westcountry (ex Westward/TSW) region without any relays?

I believe that some plans were made pre OND to recast the transmission network, there are some areas which would benefit obviously from this, however the reliance of some sites continuing requirements for FM rapidly indicated that this wasn;t practical. What I can see come 2013 is a review of some relay sites. I'm fairly certain that some will be surplus to requirements once the entire network is complete and real time measurements taken.

We do have one example of recasting albeit limited with Storeton's role where a few analogue transmitting sites have shutdown completely.

Edit ....

Wonder if a spare set of frequencies were available for a retransmit of the West version of the three PSB Muxes, on a SW through SE beam, from the old ITV 405line (now single FM service) St Hilary site, this would be useful for North Devon and Somerset, where reception from Mendip is difficult.

Simply that transmitters are where they are based on providing 4 services to the populated parts of the UK as they were in the sixties. Centres of population change, and many now densely populated areas are served by relays and will get this second rate version of digital TV.

It just seems a very unjust decision that people who happen to live in areas which just happen to be served by a relay transmitter get a poorer service.

It certainly feels like a second class service up here in Whitehaven. Our main transmitter is Caldbeck but our relay at Whitehaven provides reduced channel coverage. We had hoped to make freeview our main provider but then ITV 3&4 disappeared and it became clear we were never going to get the same selection of channels as the majority.
Ended up going with Freesat as i I can't stand being ripped off by SKY but I can imagine the two tier sysem will only benefit SKY as people won't want to miss out on channels.