Microwave relay system HK1; manufactured by Brown Boveri Cie.

A first microwave relay system was developed by Brown Boveri around 1949 under the designation HK1.

• Principle: transceiver, microwave relay system
• Operation modes: FM (F3)
• Frequency range: ?
• Sensitivity: AM (A3) / Selectivity:

• Mains operation

• mm, kg

• Dipole antennas with reflectors (similar to those in the TLD) were used as standard antennas

The HK1 was the first microwave communications system developed by Brown Boveri around 1949.

The HK1 microwave relay system was in use from 1951 to 1964; one system is on display in the Dübendorf Air Force Museum.