On Thu, 2007-04-26 at 11:07 -0400, Gene Heskett wrote: > On Thursday 26 April 2007, 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. > > > I suspect they got lost someplace in the vector math, or the fourier > transforms. Both are damndably hard to explain to someone, like me, sorely > lacking in the math background to understand it. One of the disadvantages of > having only an 8th grade formal education. Beyond that, I'm self taught, and > have occasionally caught the teacher out & made him go back to the books. :) > Aptly put. Math was my strong point, but I began my interest in electronics in grade 6. I also tormented one prof who had no real world expertise by pointing out his errors, and disproved one of his facts with a demonstration when he called me on one of my objections. I did not sign up for any more of his classes after I finished that one. > >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. > > Yup, sideband analysis tends to break down when the circuit to do the analysis > is not physically realizable. The hand on the pot has the final word anyway. > > >-- > >(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. > > > > -- > Cheers, Gene > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author) > There is something in the pang of change > More than the heart can bear, > Unhappiness remembering happiness. > -- Euripides > -- Guy Fraser Network Administrator The Internet Centre 1-888-450-6787 (780)450-6787
