Someone who knows Morse code or just going to study it, can build a simple device, shown in the figure. On a plywood Board install the battery B and the lamp L of the flashlight. Contactor In the manufacture of contact plate faulty relay. Now connect the parts to each other by wires. To increase the “range” of the Telegraph, put a lamp made from tin or heavy paper tube — a tube length of 20 cm.
Recommend to read
THE SIMPLEST FLASHLIGHT
Yes, it's probably easier to not think. For the manufacture of such "Firefly" will need only a flat battery, the light bulb is 3.5 V and the two rubber rings or a bit of adhesive tape....
ATV-KOMBI
Not so often, unfortunately, in the magazine there are descriptions of the improvised structures that exceed the current level of production of the Russian, and especially Western...
