The idea of communicating over large distances not only interested
government agencies, but piqued the curiosity others. Soon folk
were thumbing through what literature there was and building their own
equipment. A really handy experimenter could find the bits and pieces
required by looking around his house. A transmitter spark coil could
be a cast off car's ignition coil. A receiver detector could be made
by using a razor blade and safety pin. Coils are easy enough to make.
Capacitors can be made Leyden jar fashion, tin foil on either side of a
piece of glass or mica.
Higher resolution image
here.
Early amateurs on the Canadian west coast used their initials as call
signs and communicated with anyone they heard, from other amateurs to local
shipping.
This station uses a rotary spark transmitter. The receiver provides a
choice of detectors: a vacuum tube (20) or a crystal diode (18). This
drawing is of a high end station for the time.
