Mobile VHF direction finder PV-1-B, manufactured by Standard Telephone and Cables Ltd.

After the Second World War, aeronautical communications were relocated from shortwaves into the VHF air band also in Switzerland; the 108 - 118 MHz range was used for radio navigation and 118 - 136 MHz for radiotelephony.

The PV-1B VHF direction finder system was permanently installed at Dübendorf airfield and a system was also used for mobile applications.

• Principle: VHF direction finder
• Operation modes:
• Frequency range: VHF aeronautical radio range 100 - 156 MHz
• Accuracy: 3 % with a maximum DF range of 200 km

• Mains operation:

• Main direction finding console with two crystal controlled receivers, bearing display on cathode ray tube
• Remote control console, remote operation via two-wire line, max. distance 32 km
• Adcock H antenna with vertical auxiliary antenna

The PV-1B VHF direction finding system was also used at Dübendorf Airfield after the Second World War to provide bearings for aeroplanes approaching with bad weather conditions.

The direction finding system was controlled from the main console or from a remote operating console that could be operated at a distance of up to 32 km.

The system was developed by Standard Telephone and Cables Ltd.

The P-710 f/m is the name given in the documents for the automatic VHF band direction finder type PV-1B, which was apparently in mobile and also permanently installed use by the air force from around 1951.

P-710 / PV-1B