Elfinblues, My uncle was a radar specialist during WW2, and I have read many books about the RAF during WW2 and been to many museums.
May I ask you what was the trade or profession of your Grandfather before the war, and also after the war, please?
My research indicates that many men recruited into the RAF on Wireless and Radar had been employed in similar fields in Industry by such companies as the BBC, EMI, GEC, Mullard BTH etc.