I really like Marc's (AL6JV) videos. It is great fun and very educational to watch him and his team troubleshoot some of the old gear they work on. There is also a lot of humor.
In this video Marc delves into the circuitry of the Phase-Locked Loop. I didn't know that the PLL circuitry has its origins in the space program. NASA needed a circuit that would permit very narrow band reception of a signal that was undergoing the kind of Doppler shift that spacecraft produce. Viola! Enter the PLL. Far beyond Apollo, PLL circuits started to show up in ordinary radio gear. The General Electric (and JC Penny!) CB transceivers that we rescued from 11 meter infamy used PLL as the frequency determining circuit.
Marc gives a really good explanation of how the PLL circuit works. Thanks Marc.
However, Marc gives an incorrect pronuniation of "kludge" (it should sound like fudge). But he is a computer guy and is originally from France, so all is forgiven. He also redeems himself by making fun of the inaccuracies that appear in what he calls "data shites."
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