Prior to Townend it used to be Tameway Tower. Prior to that it was Little London House, a 16 storey block of flats in Caldmore.
Mb21 says " July 2019 - Transmitter moved to Walsall Townend House following demolition of the building on this site". By demolition of building I presume they mean the one on the roof as Tameway is still there lol. Assume something to do with conversion of Tameway Tower from office space to residential