This
is the easiest part of the radio to build from scratch (homemade,
homebrewed). The parts are easy to obtain at a variety of places.
We will use a coil close to the same coil as on the "Beginners #2"
crystal radio with
a few changes. The same coil on the "Beginners #2" set can be used
also. This is just a little different way to roll the coil.
Materials Needed
1 Quaker Oats box (4" Diameter size)
1 100 foot spool of #24 or #22 solid
plastic
insulated
wire Sometimes called "bell
wire"
Suppliers: Just
about
any hardware store. Radio Shack. Wire should
be solid, not stranded. It should be copper wire and not "tinned" wire
if possible. Tinned wire is OK to use, but copper wire is better.
Tinned wire is copper wire that has ben "tinned" which make the wire look like it is silver
on the outside of the wire (under the insulation). Stranded wire should
be avoided if at all possible.
Radio Shack #278-1215
Construction
Take the Quaker Oats container (empty of coarse) and
on the
open
side, come up from the bottom about a 1/2" and poke two holes
(careful). Poke the
wire
through the right hole and back through the second hole like shown
below
at the top. Pull about a foot of wire out. On the inside of the oats
box,
place a piece of tape on the wire and the two holes. This will keep the
wire from slipping out.
Wrap 25 turns of wire around the oats box going up the
box. At
this point (25 turnes) make a "tap"in the wire. See illistration below.
Roll ten more turns (total 35 turns) and make
another tap.
Roll 10 more turns (total 45 turns and make the last tap. Roll 10 more
turns (total 55) and poke two
holes next to the last turn of wire.
Cut the
wire off the spool of extra wire about a foot long. Poke the wire into
the first hole and back out the second hole. Place a piece of tape on
the
inside like on the top. This will keep the wire tight on the oats box.
Go up 1/4" from the end of the first coil amd poke two more
holes and start another coil. Wrap 10 turns of wire around the
oats box. Poke two holes next to the last turn of wire.
Cut the
wire off the spool of extra wire about a foot long. Poke the wire into
the first hole and back out the second hole. Place a piece of tape on
the
inside like on the top. This will keep the wire tight on the oats box.
You now have your coil wound like in the illustration below .
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