1. The PRM 4700 is a VHF FM Transceiver. The equipment can
be used in manpack, vehicle or ground station roles.
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
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.
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
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).