1. The PRM 4700 is a VHF FM Transceiver. The equipment can be used in manpack, vehicle or ground station roles. DESCRIPTION 2. I ho PRM 4700 is a fully waterproof, extremely compact and lightweight transceiver which operates in the frequency range 30-88MHz. Manual frequency access and nine programmable channels are available, channel selection being carried out by a single switch. 3. Channels may be programmed manually using the front panel keyboard or by using the MA 4073B Programmer or MA 4083B Fill Gun. 4. The radio may be programmed to operate in either simplex or two frequency simplex (half duplex) mode. All nine channels can be programmed for single frequency operation, two frequency operation or a mixture. 5. If required, frequency selection can be carried out manually using the front panel keyboard frequency controls. In this mode, Single Frequency operation only is available. 6. The radio can accept 16k bit/sec digital signals and this allows the use of an optional external encryption device. (MA 4423). 7. A Built in Test Equipment (BITE) facility is provided to check the transceiver each time it is used. This facility checks the accuracy of programmed channels, the control system and the receiver functions. In transmit, power output is confirmed by the presence of sidetone in the handset. 8. The keyboard provides a simple means of operational control incorporating snap action keys. When the handset is connected an audible tone is given confirming that a key entry has been made. 9. As a manpack, the PRM 4700 is normally powered by a 10V nickel cadmium rechargeable battery MA 4705A attached to the base of the unit. The battery can be recharged in situ via a front panel socket. The MA4705B non-rechargeable battery, using primary cells, is available as an alternative. (Battery life is extended by the use of 'economy1 circuits in the receive mode). The PRM 4700 can be powered by a regulated supply from the TA 4703A VHF Amplifier or the MA 4704A Interface Unit. 10. The transceiver is designed to provide automatic rebroadcast facilities using the MA 4009B Rebroadcast Unit (Voice signals) or the MA 4709A Rebroadcast Unit (Voice or 16k-bit signals). 11. In the vehicle role, the PRM 4700 is used with the Vehicle Interface Unit (VIU) MA 4704A, or VIU and 25 Watt amplifier TA4703A. Associated AMU's are the BCC 587B (Band Switched) or the BCC 588 (Wide Band).