Spider Coil Form
Deployed to Iraq I decided to build another Radio. As opposed
the usual MW AM band I decided to build a SW Radio that would tune from
about 3MHz to 17MHz. This radio was literally built from junk
gathered over a two week period while I was there. The only
parts I brought that were used are one diode and the fahnstock
clips. The PVC pipe was left over from a shower trailer
done by the Navy C.B.'s. The Plexi-glas was acquired after a
guard shack was built that checks I.D.'s at a control point.
wire was pulled from a few blown transformers to wrap the coils and the
homemade capacitor was also built from parts that were found in the
transformers case. Notice that several of the fins are pulled
back and to the right out of the way so they do not mesh?
was a unique design I thought of while making it. The whole
slides in and out to increase and decrease the capacitance.
you add fins, you change the overall max. and min. capacitance.
This way you can use the same design for a trimmer, ATU, Main
tank or what ever you need. I actually documented what each
will give you as a reference in case I decide to build a few more for
other projects. Instead of boring you with schematics and
building instructions, here
is the link I used to help me out. It's basically a mystery
with a coupled antenna tuning coil. I do have to mention one
thing that the author of this radio also suggests.
is crucial! There are about 12 different ways to hook up the
antenna, ground and coils. That's the beauty of this set,
versatile you can have fun with it for as long as you want.