Why do grown men build crystal radios is the real question!!! For me it is the first circuit I built with my Dad. There is no practical use for one of these circuits. Introducing young children to electronics is BS. Buy them a Legos set!!! The hobby is nothing more than a bunch of old men throwing big money around to relive the past. I am guilty of that also!!!
I got the Crystal Radio Bug again! So I started reading and reading. Over the years I have built dozens of crystal radio circuits. Now that I moved out here to Lancaster PA I fired up some of the old circuits. In New Jersey using a Mystery Crystal Radio circuit and a 10 foot piece of wire and ground I got 6 loud stations. Out here in PA, Zilch! I went to 30 feet of wire and still nothing! I hung an amp on the circuits and stations appeared even DX. So I decided it was time for some real headphones. After getting better headphones I could hear two stations. One stations is one thousand watts and the other is 800 watts. Now I had a 30 foot antenna and a ground. Using the Crystal Radio Test Bed see above I could now test the circuits. I won't go into great detail. Instead I will tell you what I found!
A one coil radio like the Mystery will pull in stations louder than a two coil radio. Signal is lost in the transfer of signal between coils. A single coil radio has several drawbacks. It may be inpossible to separate two different stations. You may also get a strong local all over the dial. You might also pick up a Short Wave station. I picked up the screaming preacher found on WICC shortwave.
A two coil radio has less audio. If your coils are not correct you might not get the whole dial. The circuits I build did not like stations below 1 MHZ. There is some interaction between the two circuits. You will also need more parts.
I spent weeks winding coils. The Mystery circuit is a good starting point. What you will discover is you need a 150 foot antenna or a 30 foot antenna 50 feet in the air! There are an specifications. Builder beware!
Email: John a quick question
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