Dave's #12 German Style Crystal Radio
I don't think I could call this one sexy because it looks german. My twelfth set is a distant copy of a German crystal set that I saw on an online museum. I wasn't interested in making an exact copy, but I liked how this one looked. The low box with the spider web coil looked pretty nice.
One feature of my set is the diode is on top. Why? Because they used to put the detectors on the outside of sets. That was called selling! This set allows me to try different diodes, so there is a side effect. The box is the same one as I have used in some of my tube sets. The box has been cut down. I was able to get enough cuts for three crystal sets, so you will be seeing this box often here. This was the top section. After it was cut, there was no bottom. I grabbed a piece of my ebay 3/4 inch oak lumber and cut it so when the box was placed on top, the sides had equal distances between the box and the edge of the oak. After putting on a nice edge, I used wood conditioner on the wood. Then I stained both pieces with Minwax Red Oak Stain. A step that I added was to use some fine steel wool to lightly sand the finished wood. This smooths it off very nice. Then I used Deft spray gloss finish. After all this dried, I attached the box to the oak base with 4 wood screws coming up through the bottom. Then, I attached the two 5/8 x 3/4 inch pieces of wood that will hold the T-Nuts in place.
I used 1/8 inch Garolite® here. A piece of 3/16 inch would have looked
better here. I used the 1/8 inch material because the it gives the
capacitor shafts just a little longer length for fastening the knobs.
Speaking of the knobs, I decided that I wanted to try a simpler knob. After all, the last 11 sets had the numbered knobs, this one had to be different.
The circuit is the same as my #8 set. So I transplanted the circuit to this page. I did put in a small 470 pf capacitor across the headphone jack on this one. But I have to say that there isn't much difference between having it and not. Perhaps my old ears can't detect the difference.
I used the Belden 8011 which is 12 gauge tinned copper
wire. This makes the set stand out when opened up.
There is not much that I can add, but I am very proud of this radio. It didn't take to build and I fewer construction errors.
I built another crystal radio using this same circuit. Have a look.
Best wishes until set #13 -- Dave N2DS