Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdahl!pyramid!prls!philabs!ttidca!sorgatz From: sorgatz@ttidca.TTI.COM ( Avatar) Newsgroups: sci.electronics Subject: early wireless receivers Message-ID: <4367@ttidca.TTI.COM> Date: 4 May 89 21:14:35 GMT References: <736@ultb.UUCP> <11170005@hpfcdj.HP.COM> Reply-To: sorgatz@ttidcb.tti.com (Erik Sorgatz - Avatar) Organization: Citicorp/TTI, Santa Monica Lines: 16 In article <11170005@hpfcdj.HP.COM> myers@hpfcdj.HP.COM (Bob Myers) writes: +As mentioned above, many minerals can be used - I seem to recall reading of +a WW I (or II?) "survival tactic" which involved building yourself a crystal +radio out of a lump of coal balanced on the edges of two razor blade nailed +into a block of wood! + Another method for creating a diode semiconductor useful to this purpose is to mount a razor blade flat against the breadboard (literally!) and use a safety-pin as a carrier for a piece of graphite, ordinary pencil "lead"! Again, not much current carry but enough to activate those fabulous megaohm Philmore headphones! ..those were the days! -- -Avatar-> (aka: Erik K. Sorgatz) KB6LUY +-------------------------+ Citicorp(+)TTI *----------> panic trap; type = N+1 * 3100 Ocean Park Blvd. (213) 450-9111, ext. 2973 +-------------------------+ Santa Monica, CA 90405 {csun,philabs,randvax,trwrb}!ttidca!ttidcb!sorgatz **