Only two small speakers form this makeshift phone in its simplest version.
With the use of two transformers we can increase its reach.
The speakers work in their normal function and also as microphones, generating small currents when we speak near one of them. With this, when someone speaks in front of one of the loudspeakers we can hear it in the other, albeit with a small volume.
The low volume is due to the inexistence of an amplifier, but as curiosity the experiment is interesting.
The speakers can be of any type or size. In the version with transformers, it (transformers) can be of the type of output of radios, small transformers of force, etc. the reader should experiment.
Without transformer the wires should be at most 10 meters long, but with transformer, the distance can be much higher, reaching more than 100 meters. The wires need not be shielded.
Material:
FTE1, FTE2 - Standard loudspeakers
T1, T2 - Transformers - see text
Miscellaneous:
Wires, welding, etc.
