On 14th February 1922 the Marconi Company began to broadcast a five
minute programme of speech and music within the weekly half hour
calibration transmission. The broadcasts were made weekly on Tuesday
made using the callsign 2MT from an ex-army hut in the village of
Writtle near Chelmsford. Initially the station had only 200 Watts and
transmitted on 700m (428 kHz) using an inverted-L antenna.

The enthusiastic team, led by Captain Peter Eckersley, assembled their 
transmitter together with a gramophone player, microphone, and on 
occasions a piano from the local public house, to entertain listeners. 
The regular announcement; "This is Two Emma Toc, Writtle testing, 
Writtle testing", became quite well known.
This was the first regular wireless broadcast for entertainment in the 
UK and its success provided the foundation for the formation of the BBC 
later in 1922.
Members of Chelmsford Amateur Radio Society (CARS) will operate a 
special event station to commemorate this historic event. A special 
callsign, GB100-2MT, is active during February - and on 14th February 
will operate from Writtle, close to where the original broadcasts were 
made. Operating will be on HF, as well as locally on VHF/UHF.
QSOs will be confirmed on LOTW and eQSL. Sorry no QSL cards, or bureau.
For further information - see the CARS: Website: www.g0mwt.org.uk or 
follow on twitter @ChelmsfordARS
(via Southgate 
http://www.southgatearc.org/news/2022/february/gb100-2mt-marking-the-centenary-of-british-broadcasting.htm)
(Mike Terry via bdxc-news io group)