William Nielsen's Utah Built Crystal Sets
I got interested in radio when my son asked me to build a one tube radio for a school project. I have an old electricity text that had a set that called for a # 30 tube.I knew nothing of how to even find a tube let alone the rest of the parts. Well, after lots of research and 5 years later, I have collected some parts so I decided to build something other than the ones I collected on Ebay.
The circuit for the crystal radio is from the Radio receiver projects book by Homer L. Davidson. The face and bottom are made of 1/2 inch plexyglass. The dial is an original Atwater Kent dial I found in a friends junk pile, With the variable cap still attached. The crystal set is project #4 The permeability-tuned set in the project book. The coil has 2 windings L1= 25 turns #24 enameled and L2= 97 turns same wire.
The crystal detector is completely hand made from the design of the pacient detector. I turned all the brass on a lathe and the round bottom is plexyglass also. I added the diode later and its from an old military receiver also from the junk box.
The small black dial for the grounding cap. was salvaged from an old thermal resistance meter. Lots of great parts on those things. The ground and aerial posts are also original Atwater Kent parts also.
The coil slider coil is wound on a PVC form. I threaded brass rods to hold it together and the contact is made from a cabinet door bullet catch, Most hardware stores have them.
Last of all, The baldy phones were found at a local garage sale, I think brand new. Nathianel Baldwin radio works was located just 5 miles from my house. The building is still standing and is now converted into many small shops.
I think its great to receive a radio signal LOUD, Without batteries. Thanks again,