On Thu, 2007-04-26 at 17:45 +0930, Tim wrote: > Tim: > >> Sounds like they need to, also, employ someone who used to be a teacher. > >> Someone who's used to the idea of having to train, as the main thing > >> that they do. > > Gene Heskett: > > On the face of it, that is a good idea. Till that old saw about > > "those who can't do, teach" comes crawling up out of the back of my > > mind, having had it quite amply demonstrated in my nearly 57 years of > > chasing electrons for a living. The other corollary to that is that > > those who can do, and then try to teach, have a hell of a time trying > > to reduce the language to something that actually works for TV-101 > > classes. > > ;-) Generally, we had the opposite problem at college. Teachers who > learnt electronics at college, then became teachers, were worse than > those who worked in the industry, then became teachers. For one thing, > they knew the difference between theory and practice. > > 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. > 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. > Yes, I know that you can put a 1 kHz signal on top of a 1 MHz one, and > then filter one away from the other. Theoretically, that's fine. But > it doesn't get around the fact that I had grabbed the pot and changed > the carrier level. It sure didn't have a constant carrier level in my > hands. > Apples and Oranges. The resulting signal is technically not the carrier because you just modulated it. The resulting signal is more complex than what you perceive, but in the most simplistic terms it appears to be the carrier at varying levels. Without learning the complex math and physics that constitute a communication system you can not feasibly determine what constituents are diminished to the point that they can be ignored. It is the same with software development and design, you can leave out some subroutines or invocations of a subroutine in some circumstances depending the actual conditions that are used to trigger its use, but by not using it where it is required will diminish the quality of the resulting program. > -- > (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. >
