User Manual Part 1

SECTION 1 GENERAL INFORMATION

1.1 SCOPE OF MANUAL

This service manual contains operation, programming, alignment, and service information

for the E.F. Johnson Company 4300 series VHF mobile radio.

1.2 TRANSCEIVER DESCRIPTION

1.2.1 GENERAL

The 4300 series mobile transceivers operate on various types of channels and with various

signaling protocols (see following information).

VHF: 136-174 MHz, 20 watts

1.2.2 ANALOG/DIGITAL OPERATION

The 4300 transceivers use a digital signal processor (DSP) to provide IF and audio filtering

and signal modulation functions. This allows operation on the following types of channels,

backwards compatibility with existing equipment, and also the ability to operate on various types

of radio systems.

Narrow Band Analog - FM modulation is used with a maximum deviation of 2.5 kHz. This

mode is usually used in systems with a channel spacing of 12.5 or 15 kHz.

Wideband Analog - FM modulation is used with a maximum deviation of 5 kHz. This mode is

usually used in systems where the channel spacing is 25 kHz or 30 kHz.

Project 25 Digital - Operates on Project 25 compatible systems. The voice is digitized, error

corrected, optionally encrypted, and then transmitted using C4FM modulation according to the

Project 25 standard. This mode uses a channel spacing of 12.5 kHz.

1.2.3 OPERATING PROTOCOLS

The 43xx transceivers can be programmed for all the following operating protocols. The

conventional analog protocol is standard and the others are optional (available only if enabled by

factory programming). Refer to Section 3 for more operation information.

• Conventional analog

• Conventional Project 25 (digital)

• Trunked Project 25 (digital)

• Trunked SMARTNET

/SmartZone

analog or digital