Dave's #10 Crystal Radio "The Old Buzzard"
Looks like you made it to my #10 set, or did you skip to this one? Now that I have completed 10 crystal sets, it is time that I make a new directory on my website. This one is getting pretty crowded! So you will be seeing a 11-20 link soon! I am also giving the radios a name after I build them. This one is The Old Buzzard. My friend George, K2XL uses that term for this old fart stuff.
This set isn't completely homebrew. One of the fun things about this hobby is find something around and make it fit and work in the situation that you pick. This is what I did here. I have become an "ebay junkie". Maybe I shouldn't let this secret out as many of you might go there and compete with my bidding. Dave doesn't like to pay much for his stuff. I got a really good deal from Big Al a week or two ago. I bought a bunch of capacitors, coils, etc on an auction and mixed in was this coil and capacitor all connected together. I noticed that there was a second coil inside the first one. The wheels started turning right away. So I hooked up a diode and earphone, connected to my antenna and ground and I was receiving signals!
One thing I noted was that this crystal set was pretty loud, but not much for selectivity. That is perhaps the wire isn't the high Q litz wire. However it was great having a chance to listen to a crystal set made with some really old buzzard parts.
I won't go into many construction details except I used a scrap piece of my 3/16 inch Garolite®. That is why the knob is taller than the panel. I stained a piece of oak with Minwax red oak stain, and then applied some shellac. There is a groove cut in the wood and the panel is force fit in that slot. Hopefully it won't splinter the wood, but so far, so good. I would like to use a smaller tuning knob but I had to use that one because of a feature of that knob. The capacitor will turn round and round, non stop. There is a wire braid attached between the rotor and a terminal. If that capacitor were turned a lot in one direction, that wire would break. So hidden under the knob is a little homebrew stop that I made. The knob has a groove inside that the stop will travel in. The knob will then stop when the end is reached. Problem solved!
Other than that this set is kind of a plain circuit, but great on looks. I like this one already!
So stay tuned for more sets. I have more tube sets coming along with plans to build a loop antenna. Please bookmark this site and tell your friends! 73, Dave