TT, A friend from way back had a "crystal" radio, where the capacitor was a crystal that you pushed a mounted sharp wire against, depending where on the crystal you pressed the different frequencies came through.
The more regular crystal radio taught me a lot about the electromagnetic spectrum, then subsequently the broadcast side. An alternating current that changes so fast the resulted fields created by the movement do not have time to collapse and are radiated away. The electrons in the crystal radios antenna move according to the broadcast signal and the diode clips this to one direction only (DC) and the very sensitive earphone vibrates accordingly. Thanks for the (off thread) memories. Tony On Friday, March 20, 2020 at 9:48:10 AM UTC+11, TiddlyTweeter wrote: > > One can! On radio the simple crystal set works to pick up AM, so long as > it broadcasts. I'm sure many kids like me ruined a ear on one :). > > They consist of a diode, a variable capacitor (for tuning) a very long > wire for the arial,and an earpiece. Earthing is advised too (using it > during an electrical storm could be fatal :). > > They don't need batteries. The AM signal itself generates the power needed. > > TT, x > > -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/6d21a93f-38ee-42b3-a00a-ed07889bc4c5%40googlegroups.com.
