It was originally built in the 1980s as a fill-in relay for UHF analogue colour television covering the communities of Brechfa, Horeb and Aber Goleu.

It consists of a 12 m self-supporting lattice steel mast standing on a hillside which is itself about 290 m above sea level.

Brechfa transmitter re-radiates the signal received off-air from Carmel about 30 km to the south.

After the switchover process, analogue channels had ceased broadcasting permanently and the Freeview digital TV services were radiated at an ERP of 3.6 W each.

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