Tim: >> I could never get any lecturer to give a sane explanation of AM. They'd >> tell us that the carrier was a fixed amplitude. I'd argue that AM was >> modulating the carrier, therefor it has a varying one. I'd even >> demonstrate by cranking the pot up and down to give a 1 Hertz AM. None >> of them could give a reasonable explanation. Yes, they could give >> strange ones, but none that fitted the situation demonstrated. Guy Fraser: > It isn't that simple unless you are only learning the basics. If you > are learning theory and fundamentals it is far more complex. You did > not do a detailed analysis of the signal you generated to determine > the constituent parts of the resulting signal, so your demonstration > was in no way a proof. Well, proof in as much as I was "modulating the carrier" as the name AM implies. And with simple detection, you could get the modulating signal back out the other end. Elsewhere I'd used circuitry where you fed carrier and signal into a VCA, and created AM in a similar method, albeit less "hands-on". ;-) i.e. Signal was actually modulating carrier strength, it wasn't a case of "mixing" signal with carrier. I could never get any lecturer to explain what AM really was, if it wasn't actually AM. They seemed to treat much of it as if it were some religion, that you'd have to accept on faith. But, yes, this was the basic introductory part of the course to RF, some 20 odd years ago. And thanks to the lack of good teaching in that part of the course, I didn't continue on with RF. I left that alone, and did other aspects. If they couldn't teach the basics, what's the point of having the same lecturer for the next part of the course? I don't do learning by rote, and have very little respect for anybody who does. I did ask other students if they understood it, and didn't find any that did. You can't do that sort of thing without understanding it, certainly not properly. They all treated it like some sort of magic. I'm sure the same (useless) approach is taught with computing, these days. It might explain why so much is so bad. -- (This box runs FC6, my others run FC4 & FC5, in case that's important to the thread.) Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists.
