The BATC organises conventions known as CAT (Convention for Amateur Television) at locations around the UK.
Details of previous CATs, including presentations and videos of the event can be found on the batc wiki pages:
CAT19 Finningley: https://wiki.batc.org.uk/CAT_19_Finningley
CAT18 and the BATC General Meeting was held at the Midland Air Museum on the weekend of September 15th and 16th 2018 – https://wiki.batc.org.uk/CAT_18
CAT17 was held at Finningley Radio club – https://wiki.batc.tv/CAT_17
Videos from previous CATs can be found on the BATC Youtube channel – https://www.youtube.com/channel/UCUWLnUZllytlcCFd93tnBzw
BATC also attends various radio rallies around the country with the BATC shop and Portsdown Clinic.
Full details of these events are posted on the BATC forum
A full list of rallies in the UK can be found on the RSGB website.