I am an electronic engineer (HNC & City & Guilds Full Tech. Cert), formerly working for many companies in the UK including Ferranti, Mullard, Plessey & most recently Siemens. I am now retired and to keep my brain active I restore vintage radio receivers. I also sometimes add a bluetooth module to them to make them more useful in the current age. I am competent with both valve & transistor circuits. I am a member of the UK Vintage Radio organisation and have several articles on that website.