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Science Buddies: "Ask an Expert" • Only hearing static
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Only hearing static

Posted: Tue Apr 09, 2013 6:20 am
by ninoschkabaca

My daughter who is in 3rd grade put together the crystal radio. Her project is due on April 16th (Tues).

Question: Should we clearly hear the local AM radio station (KGO Newstalk radio 810)? We live in the San Francisco Bay Area, zip code 94030, area code 650. We ask because we only hear static.

Question2: We are not sure which one is the diode vs the resistor. Unfortunately these items were removed from the baggies before I could make a note.

- One item is mostly beige with lines

- Second item is clear with 2 red/pink colors and a green color (that is not centered)


Re: Only hearing static

Posted: Wed Apr 10, 2013 4:18 pm
by k4gfwgerry
The resistor is the one with the red, red, green bands. It's value is 2200 ohms (see color code chart at http://www.elexp.com/t_resist.htm). The other one is the diode. The anode (+ side) is the one without the stripe. Current flows from the anode to the cathode which is the end with the stripe. I hope that helps.