The radio   Kleinfunksprechgerät KL 4

was a UHF radio for short distances used by different authorities. Pictures in the handbook hint it was built to be used by the army. Other editions also were built e.g. for firefighters.
It can be used with rod or wire antennas. It is a tube radio, the vibrator is built in. The housing is watertight.
It uses a silver-zinc-battery with four cells. One cell is for filament, the other three cells provide the voltage for the vibrator.

Frequency range:

172.0 ... 172.7 MHz

Channels:

6

Frequencies:

172.0; 172.1; 172.3; 172.4; 172.5; 172.7 MHz

Mode:

Frequency modulation, F3

Output HF:

400 mW

Sensitivity:

1.5 µV

Bandwidth NF:

300 ... 3000 Hz

Operation hours:

7 .. 8 hrs with one battery load

Antennas and range:

Rod antenna: 3 ... 5 km

Wire antenna (extra bag) 8 ... 12 km

Undisturbed view: up to 50 km

Tone call:

1750 Hz, button on the hand mike

Battery:

Silver-Zinc-Battery 4 cells à 1.5 V, 10 Ah

1 cell for filament;

3 serial cells for the vibrator

Tubes:

9  tubes DF 906

10 tubes DF 904

3  tubes DL 907

Year of issue:

1952 / 1953

Built by:

Lorenz