4 Wire Analog Telephone or Audio FOM II Modem

These serial data modems are currently in use in the UK in an unusual application. This application involves military aircraft development. Fighter aircraft have to be able to operate in very demanding environments, including those with close proximity to high power RADAR and other transmitters. In order to ensure that the sophisticated electronics on board will work properly, part of the design process demands that the aircraft are "illuminated" by such RADAR systems at distances of tens of feet. The essential communications required during such tests means that the use of copper conductors between the control center and the aircraft is simply not possible. Only fiber can accommodate the distances required and "tune out" other interference.

In the UK, the problems of distance and interference on board these aircraft have been solved by the use of a system which incorporates two F272xB VERSITRON four wire converters. Contained in a fully screened unit, each piece of equipment allows for the use of up to four standard aircraft headsets. Thus, giving perfect clarity of communication.