Foundations Of Amateur Radio

Foundations of Amateur Radio Previously I've explained how Radio-teletype or RTTY works from a technical perspective. If you recall, it uses a technique called Frequency Shift Keying, or FSK to encode digital information. It does this by transmitting a carrier across two alternating frequencies, allocating one as a SPACE and the other as a MARK, or as a binary 0 and a binary 1. There are several other ways of encoding information and today I'm going to look at Phase Shift Keying, or PSK, which I find humorous, because Phase is spelled with a P, but it sounds like an F, which links the FSK and PSK together, but then I've always had a strange sense of humour. Imagine if you will a sine wave. It's the one you learned in high-school, nothing sophisticated about it, just keeps going up and down over time. Now imagine another one. Also going up and down over time. If these two sine waves are synchronised, going up and down at the same time, the difference between them is 0. If one of the sine waves is going up,