U.S. / German WWII genuine Lichtsprechgerät 80 LiSpr.80 in top condition. In this condition very hard to find ! It comes out of a big radio collection . What you see is what you get !

This is a 2-way audio communication equipment.
The signal is transferred on a light beam from a 5-watt bulb.

The light beam is modulated with a light phase modulator.
The light beam is AM-modulated with a moving prism.
The position of this prism is manipulated of the transmitter audio amplifier.

Red and IR filter can be inserted in the beam.
Receiver and transmitter have one lens each.
Light detector is placed 250 mm behind the receiver lens.
Diameter on the light detector is less than 1 mm,
so the direction of the unit is very important.
Diameter of the light beam is only 1.4 meter at 250 meter from the transmitter lens.
This will give a diameter of 7 meter 1 km away.
An RV2P800 tube is connected directly to the light detector as a preamplifier.
Diameter on the receiver and transmitter lens is 80 mm.
Manufactured by Carl Zeis Jena.