It was originally built in the 1980s as a fill-in relay for UHF analogue colour television covering the communities of Erwood, Llandeilo Graban and Llansteffan.

It consists of a 20 m self-supporting lattice steel mast standing on a hillside which is itself about 215 m above sea level.

After the switchover process, analogue channels had ceased broadcasting permanently and the Freeview digital TV services were radiated at an ERP of 2 W each.

The UK's digital switchover commenced at Carmel (and therefore at Erwood and all its other relays) on 26 August 2009.

Channel 60 was replaced by the new digital BBC A mux which started up in 64-QAM and at full power (i.e. 2 W).