Dave's #5 Set. Ain't That Brass Pretty?
I finished it! I won't tell you how much money I have been spending on these sets. But, I am having a ball. Thanks for hanging in with me this far. This crystal set is an experimental model. I wanted to test some of the fabrication processes and circuits before going on. My next set will have the black Garolite® material mounted on an 8x10 inch box. I took some leftover mini plywood, splashed a little Minwax stain on and drilled the holes using my new drill press. The holes turned out pretty well, but I have to take the time to clamp my work before drilling.
I was especially anxious to try making a tap switch. Dan, W7OIL sent me a picture of a tap switch he had fabricated. The design was simple and easy to build. I found a piece of 3/8 inch wide brass strip. I drilled a couple of holes and mounted a little button (a half inch wood hole plug button). The picture below shows the detail of the construction of my tap switch. I went to Lowes and found some fixture knurled thumb screws, 8-32 size. I also found some mail order but so far not in quantity. These make the switch tap contacts. They don't look like they are solid brass, only brass color. The switch arm is likely to scratch the finish, but then my set will look antique.
The exact circuit for this radio is not yet available, but
is close. A major difference is that I am using a spider web coil
with litz wire. These coils are very nice when you don't have a lot
of height to play with. Gone are the budweiser coil forms. I purchased
some "store bought" coil forms. They take a little getting used to as
the dimensions are somewhat different from the "Bud" forms.
So far, the radio performance is standing up. It seems to have better sensitivity than all the others (#4 is pretty good too).
This set has brass hardware. I used 8-32 fillister head screws (because I like them), washers and nuts. I also purchased some matching thumb nuts. This gives my crystal set "the look". I plan on using this hardware in some of my future radios.
There is better selection for advanced antenna matching. The antenna coil/capacitor combination can be in series or parallel or the antenna variable capacitor can be switched out completely. I have 3 antennas that I am able to test these sets with and I will be adding a fourth (about 30 feet long) in the near future.
So as an experimental radio, I am quite pleased. No one, except for you all will know this was a test set. Please don't tell anyone.