Next Wednesday 31st October, viewers in parts of Wales will need to retune their Freeview TVs as frequencies change to ensure a smooth rollout of 4G mobile services in the area next year. 4G mobile will use frequencies previously used for TV in the UK. Viewers that don't retune will lose entire groups of channels.
Transmitters affected by the retune event are largely in West Wales, especially in and around Pembrokeshire and Aberystwyth. The full list appears below.
Pop up messages on channels including ITV1 and S4C will run for five days in the run up to the event advising viewers of the forthcoming event. Due to technical constraints, the BBC multiplex will be unable to transmit these pop up messages.
The details of next week's retunes are as follows -:
note: BBC B=HD multiplex, so if you haven't got Freeview HD, disregard this. BBC-A is the main multiplex carrying BBC One, Two, etc, D3&4 is the ITV/S4C/C4/C5 multiplex. ARQ B is the commercial multiplex broadcasting channels such as Film 4.
Preseli BBC B moves from ch50+ to ch40+ and ARQ B moves from ch49- to ch39+;
Relay sites:Aberystwyth D3&4 moves from ch61 to ch49;
Beddgelert BBC A moves from ch62- to ch50;
Briton Ferry temporary power change on all services to 32W ERP until March 2013
Broad Haven BBC A moves from ch61 to ch51 - power boost from 8W to 16W ERP;
Croeserw HP/VP BBC A moves from ch61 to ch49;
Cwrtnewydd power boost from 4W to 8W ERP only
Dolgellau BBC B moves from ch62- to ch50;
Fishguard BBC A moves from ch61 to ch49;
Glyncorrwg BBC A moves from ch49 to ch39;
Haverfordwest BBC B moves from ch48 to ch47 - power boost from 100W to 200W ERP;
Llewyn Onn power boost from 7W to 14W ERP only
Mynydd Pencarreg BBC A moves from ch61 to ch49;
Newport Bay D3&4 moves from ch51+ to ch41;
Penrhyn Coch BBC A moves from ch62- to ch50.
Pembroke Dock BBC A moves from ch61 to ch49 - power boost from 5W to 10W ERP;
Rheola BBC B moves from ch62- to ch50;
Trefin power boost from 50W to 100W ERP only
Tregaron D3&4 moves from ch62- to ch50;
Ynys Pennal power boost from 4W to 8W ERP only
Ystumtuen BBC A moves from ch49- to ch39 - power boost to 20W ERP.
Changes at the Preseli main transmitter will be conducted overnight and completed by 6am, but many relay sites will not see services back to normal until later in the day, with the final sites having had their frequencies changed by 3pm. Interruptions to the Freeview HD service are expected at all relays of Preseli, as they rely on the main transmitter's feed, although satellite back up is available for relay sites to work off.
It is possible that some viewers near the West coast of Wales, who have modern TVs that can encode MPEG4 may pick up Irish Saorview from Mount Leinster transmitter in SE Ireland when they do their retune. Saorview is now available on a new frequency, which is not blocked by the Preseli transmitter in Pembrokeshire as was the case until now.
- Further retunes around North Wales, the Isle of Man and the Border TV region take place on the 14th November. Full list of all sites click here.
Although Digital UK has been kept alive beyond the end of switchover to be responsible for retunes such as these, once 4G mobile comes on air it will be the responsibility of a new organisation called Digital Mobile Spectrum Limited (DMSL) to provide assistance to households with resulting interference who rely on terrestrial (Freeview) reception on their main set and do not already have satellite or cable.