Technical Manual

Technical Manual

1. General Description

The MX940 series employs state of the art design and construction methods to deliver

a range of high performance, very reliable radio base stations and repeaters. They are

ideally suited for use in VHF or UHF two-way voice communications radio systems.

Fractional synthesizers’ and the two-point modulation method give the added

advantage of linear frequency and phase response from DC to 3 kHz for accurate

reproduction of voice and low frequency digital signalling systems. The Receiver and

Exciter circuits are contained in single special aluminium housing together with the

associated audio processing and digital control on a single circuit board. The Power

Amplifier is also contained in its own extruded aluminium housing and can be easily

removed from the main chassis. The MX940 also incorporates ‘Plug and Play’

technology and performs automatic self-calibration. A complete module changeover is

field replaceable in very short time.

The MX940 employs some unique features in its design and much thought and

consultation has been used to provide a product that offers an extreme degree of

flexibility for the installer and service person. For example, all options may be easily

field retrofitted at a later date. In addition, servicing is simplified with PCB's having

all components on one side of the PCB. This permits the Technician to diagnose

problems while either still connected in the chassis or powered simply and

independently on the test bench.

The flexibility of the MX940 series allows it to be configured for a wide range of

applications without removing any covers.

Standard MX940 applications include:

 Analog Voice Repeater

 DMR Repeater

The MX940 incorporates special technical features, of which the key ones are listed

below:

 Extremely low conducted emissions

 Extremely low transmitter spurious

 Fast transmitter on time

 Transmitter frequency response down to DC

 Low group delay distortion

 Full sub band RF switching bandwidth

 No re-tune design for receiver and transmitter

 Fully software programmable

 Built in diagnostics

 CTCSS, Full duplex DCS, DMR Colour codes and many other options included

as standard

 Programmable channel spacing

 Flash upgradeable