Tech:FFOBZB

FF OB/ZB
FF OB/ZB deployed in Vienna on EH19

The designation FF-OB/ZB stands for "Field telephone, local battery/central battery operation". The unit consists of a fiberboard box with a flap under which the connections, handset and other accessories are housed. As an optional accessory, there is a plug-on dialing attachment that allows operation on a trunk line or on a private branch exchange. An exchange cord and a battery extension cable, both housed in the device cover, are supplied with the device as accessories. The battery extension cable can be used at particularly low temperatures to stow the battery in the hopefully warm trouser pocket to prevent an unwanted discharge. The handset is not a simple telephone handset. The handset has a button that turns on the microphone when pressed. When placed on the housing cover, this button safely separates the microphone from the earpiece to prevent unintentional eavesdropping. This is the reason for the note on the housing cover "Replace handset or risk of eavesdropping".