Thanks kindly..
I did think it was to do with comms but he doesn't ever speak about it, its just that generation I guess pluss hes 93, he says he cant remember his serial number or squadron but I find that a little hard to believe, I do have his Warrant officer wrist badge which does have some very faint writing on the back of it, I'll be buying an eye loupe then...lol.
Much obliged.