Honeycomb coils make good receivers for homemade radio sets. They offer an advantage over other types of receivers because the coils are interchangeable. This means the radio operator can tune them to any wavelength. Honeycomb coils also take up less room than other types of coils, and they operate more efficiently. To make honeycomb coils, build or purchase a coil former so you can wind wire with a coil in a honeycomb pattern.
Pare down either end of the dowel to form handles 0.79 inches wide on either side. Sand any rough edges smooth.
Drill small holes all around both handles of the dowel, at the edge of each handle towards the centre. Drill 16 holes on each side, and space holes evenly.
Fix the knitting pins into the holes on both ends of the dowel. Secure with carpenter's glue and let dry. These will make the pegs for your winding form. You'll wind the honeycomb coil around these pegs.
Coat a thick strip of paper in wax. Rub the waxed paper around each metal peg of the winding form. This ensures you'll be able to remove your coil easily after you're finished winding it.
Begin winding your wire around the coil form. You can use any number of winding patterns to form a variation on the honeycomb pattern. Weave the wire over and under the pegs on either side. Try a pattern such as over one, under four, or over two, under three, or whatever pattern best suits your needs.
Apply a thin layer of varnish or finish to the coil. Let dry, then slide the coil off of the winding form.
Things you need
- Thick wooden dowel, 1.95 inches in diameter, 3.15 inches long
- 32 knitting pins
- Carpenter's glue
- Thick paper
- Copper wire, 0.02 inches in diameter