Freeview viewers in the Swansea area and parts of south and central Wales may need to retune their TV equipment on July 17 to continue watching some programmes.

Some Freeview channels are moving to new airwaves to allow for the future development of new mobile broadband services.

Following a decision by the UK Government, transmitters are being updated region by region as part of a major engineering programme being carried out between now and 2020.

The required changes will take place at transmitters in the areas listed below:

Engineering work at the Carmel and Kilvey Hill main transmitters will begin shortly after midnight and Freeview channels will be off-air overnight until 6am. After this, any viewers receiving their TV signal from these who find they are missing channels can retune.

Work at smaller local transmitters will take place during the day and services may be subject to disruption until late afternoon. Satellite and cable TV are not affected.

Around 200,000 homes are served by the affected transmitters. Freeview will be running an information campaign to prepare people for the change, including advertising and on-screen messages.

Retuning should be straightforward and some TV equipment will retune automatically. Some older aerials may need to be replaced to continue receiving all channels. Viewers may be eligible for free in-home support, including aerial work if needed.

Anyone who needs advice, or who finds they are still missing services after retuning, can visit the Freeview website at freeview.co.uk/tvchanges or contact the Freeview Advice Line free on 0808 100 0288.

Further information is available online at freeview.co.uk/tvchanges.