The British Amateur Television Club has made available videos of the talks given at the CAT17 event held at the Finningley Amateur Radio Club Sept 9-10
 
Among the videos are: 

• Es'hail 2 satellite update by Dave G8GKQ
• DigiTwist an experimental low-cost satellite tracker by Brian G4EWJ
• Introduction to Optical Communications by Bernie G4HJW
• 5.7 GHz Linear Amplifiers for the ADALM Pluto by Brian G4EWJ 

CAT17 BATC Videos - https://www.youtube.com/channel/UCUWLnUZllytlcCFd93tnBzw/videos
 
BATC - http://www.batc.org.uk/