EV>TW>I built my first crystal set up in Great Falls Montana in 1947. At night   
   EV>  >I used to pick up XERO the Full Power Mexican Station down near   
   EV>  >Clint Texas.   
      
   EV>Since reading about your building a Crystal Set, it made me remember the   
   EV>one I built in High School Radio I Class 1957-1958.   
      
   EV>One thing I remember is Shellacking the Toilet Paper Roll's CORE and   
   EV>winding a long piece of wire on it, and then winding a second Coil over   
   EV>the first one.   
      
   EV>I've noticed the CORE has a bigger diameter Now than when I was younger.   
      
   EV>I can remember each Roll having 365 sheets on them back in the late   
   EV>1960's to early 1970's (when I married the YF) and a package of Four   
   EV>Rolls cost 79 cents U.S.   
      
   EV>Now a "Double Roll" in a package purchased recently has about 2/3rd's of   
   EV>the paper on it as it was back in the good old days of the late '60's.   
      
   EV>And since the Core is so large it would take a much longer length of   
   EV>wire to wrap 400 (+ or -) turns on the core.   
      
   EV>Wouldn't that change the Inductance in the Circuit???   
      
   Inductance of a coil is dependent on 4 factors.   
   Wire Diameter, Number of turns of wire, coil diameter, and the Relative   
   Permeability of the coil core material.   
   Air has a permeability factor on 1 so it is really not a factor in air   
   core inductors.   
   I used and on line calcualtor to check and doubling the diameter of the   
   coil almost doubles the Inductance of the coil.   
      
   EV>BTW, I didn't use a Germanium Detector with a Wire Contact when I made   
   EV>mine, I had to go to get a 1N34A Crystal Detector when I built 'MY'   
   EV>Crystal Radio Set.   
      
   EV>I think I paid 99 cents U.S. for the 1N34A in 1957.   
      
      
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