Nazis win the war because of interferring with history..?

I'm absolutely positive this episode was in TFTDS, with James Coburn stating : 'Well, that's what happens when you interfere with history!'
A man, named Charlie, who's a 'radio ham' hears German radio over the airwaves, translating it and finding out, it is a wartime transmission. The message has a sinister tone for Charlie, as he determines it's a Nazi U-Boat - that's not all - he finds out the ship they are about to sink is the one his dad died on! (The dad he's never seen, of course).
So... being a radio ham, Charlie tries his hand at 'sending' a message back in German (Never mind there's no code!). He transmits back, 'not' to sink the ship.
The following morning, Charlie wakes to find his dad alive, stating to him : 'I did it, I did it, Dad, I saved you'. Of course, his dad doesn't know what he's talking about. But the Dad gives Charlie a kind of 'badge/permit' thing for him to wear, saying to him that he should wear it, 'as if we haven't enough trouble already' he says! Charlie is then greeted by a guy in a black uniform - an SS uniform!! He says hello to Charlie and his dad. Charlie looks out of the window, sees the 'Swastika' flying everywhere, notices on his badge even, there is a small swastika, German cars, I think outside and a newspaper with a swastika on it, mentioning news from 'The Chancellor'!! Yes - you've guessed it! Charlie's however good intentions, changed the course of the war and the Nazis won!!! But I don't see this episode listed anywhere - can anyone help? I was sure it was TFTDS, especially as I remember James Coburn at the end stating
about interfering with history?????????