EF Johnson Technologies 3800 series User Manual

Section

1

Section 13800 Information

1.1 General Description

The EF Johnson Technologies 3800 Series Digital Repeaters are designed specifically for radio trunking
operations. The 3800 integrates the functions of radio repeater and trunking channel controller into one
unit. See Figure 1.1.

Figure 1.1 3800 Series Digital Repeater

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3800 Information

The radio
component provides a transmitter and receiver with software programmable frequency and power
selection. Transmitter and receiver signals are encoded and sampled by dual Digital Signal Processors
DSP).

Channel controllers in each repeater manage the control and traffic channels for frequency assignments
and transmitter power level. The local site controller is integrated into one of the repeaters. The Trunked
IP25 System supports the ability to have backup site controllers, but only one site controller is required
per site.

Multiple repeaters may be used per site to accommodate multiple frequencies, traffic level, and provide
radio channel backup. One repeater is required for a control channel and one or more repeaters for traffic
channels.

A built-in ethernet interface lets the repeater communicate over the Trunked IP25 System IP network to
other system components.

1.1.1 Models & Features

The 3800 Series Repeater consists of various models and features. Please refer to the 3800 Digital
Repeater Service Manual for descriptions of the different models, identification and part number
information.

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3800 Information

1.2 Functional Description

The EF Johnson Technologies 3800 Series Digital Repeater is a trunked repeater with built-in trunking
control. The Trunked IP25 System Channel Controller function is integrated into the repeater subsystem.

The 3800 Repeater uses frequency synthesizer and Digital Signal Processor (DSP) technologies to
provide digital control of the radio channels. Software defined configurations allow for quick updates and
programmable operating frequency, output power, and other key functions.

Multiple repeaters may be used per site to accommodate multiple frequency bands and provide radio
backup. The 3800 is comprised of the following functional modules
( Figure 1.2):

Figure 1.2 3800 Repeater Subsystem Functional Diagram

Channel Controller

All channels are managed by the integrated Channel Controller. The controller provides overall channel
control for control and traffic channels in a repeater. It manages the radio transmitter and receiver
frequency assignments and power lev els. Th e Chan nel Controller checks channel status and reports any

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3800 Information

channel failures or processing errors to the Site Controller. One Channel Controller is used for each radio
repeater subsystem (in multiple repeater systems).

TXDSP Module

The TXDSP module manages the repeate r radio transmitter interface. This module prov ides chann el
encoding with forward error detection and correction coding. It receives data packets from the channel
controller and creates a signal for the transm itter.

Radio Transmitter

The Radio Transmitter is digital synthesizer based to ensure on-frequency and high stability operation. It
converts the processed signal from the TXDSP module into a radio frequency (RF) signal for
transmission.

Radio Receiver

The Radio Receiver is digital synthesizer based to ensure on-frequency and high stability operation. It
receives and converts the radio frequency signals for processing by the RXDSP module.

RXDSP Module

The RXDSP module manages the repeater radio receiver interface. It processes the received signal
samples from the radio receiver into data packets. The module then sends the data packets to the Channel
Controller.

Ethernet Inte rface

The repeater communicates over its Ethernet interface with the Site Controller, Dispatch Console, and
Network Management System (NMS).

EIC Module

The EIC module provides a user interface to the repeater including a 2-line display and push button rotary
knob for menu navigation.

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3800 Information

Power Supply

The power supply accepts the AC line power input and converts it into the various DC power
requirements of the repeater.

1.3 System Configuration

The 3800 Repeater is typically used as the repeater component in an EF Johnson Technologies Trunked

TM

IP25
IP network configuration lets a system administrator manage the radios and system components exactly as
if they were computers on a LAN. See Figure 1.3.

Configuration of 3800 repeaters is performed through the Network Management System (NMS). Refer to
Section 3.3, “Trunked System Operation”in this manual for system operating information.

System. This is an Internet Protocol (IP) Local Area Network (LAN) based radio system. Using a

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3800 Information

Figure 1.3 Trunked IP25 System

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3800 Information

1.4 Safety Information

This repeater emits radio frequency (RF) energy when transmitting. Make sure to observe

all RF energy exposure standards when installing, testing, repairing, and operating this radio equipment.

The FCC has adopted a safety standard for human exposure to RF energy. Proper operation of this
repeater under normal conditions results in user exposure to RF energy below the Occupational Safety
and Health Act and Federal Communication Commission limits.

- Do not allow the antenna to touch or come in very close proximity with the eyes, face, or any

exposed body parts while the repeater is transmitting.

- To comply with FCC RF exposure limits, do not operate the transmitter of a stationary radio (base

station or marine radio) when a person is within fourteen (14) feet [four (4) meters] of the antenna.

- Do not operate the repeater in explosive or flamm ab le atm ospheres . The tran sm itte d repeater energ y

could trigger blasting caps or cause an explosion.

- Do not operate the repeater without the proper antenna installed.

- Do not allow children to operate transmitter equipped repeater equipment.

Note The above warning list is not intended to include all hazards that may be encountered

when using this repeater.

This device complies with Part 15 of the FCC rules. Operation is subject to the condition that this device
does not cause harmful interference. In addition, changes or modification to this equipment not expressly
approved by EF Johnson Technologies could void the user’s authority to operate this equipment (FCC
rules, 47CFR Part 15.19).

The information in this document is subject to change without notice. EF Johnson Technologies will not
be liable for any misunderstanding due to misinformation or errors found in this document.

1.5 More Information

Additional information is available for the 3800 Digital Repeater. Contact your supervisor, site radio
administrator or EF Johnson Technologies representative should you need one of these additional
manuals. Refer to the following:

- EF Johnson Technologies 3800 Digital Repeater Installation Manual

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3800 Information

- EF Johnson Technologies 3800 Digital Repeater Service Manual

- EFJohnson Trunked IP25 System Installation & Configuration Manual

- EFJohnson Trunked IP25 System Administration & Maintenance Manual

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Section

2

Section 2Controls & Indicators

Most controls and indicators on the 3800 are located behind the front panel. Figure 2.1 shows the 3800 with its front
panel removed. 3800 controls and indicators are located on the Site Controller card, Channel Controller card, and the
External Interface card. These are described and illustrated in greater detail in the following sections.

Figure 2.1 3800 Repeater with Front Panel Removed

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Controls & Indicators

Site Controller Controls and Indicators

Auxiliary Status LED

LED Indication

Software Version < 3.0

Software Version > or = 3.0

On Solid

Ethernet link datarate = 100 Mbps

Site controller is in standby as redundant

Flashing

NA

Site Controller is active in Trunking

Off

Ethernet link datarate = 10 Mbps

NA

2.1 Site Controller Card

The site controller card provides the high-level call processing for the entire site. Unless using backup site controllers,
only one repeater in each system contains a site controller card. The Site Controller card’s controls and indicators are
illustrated in Figure 2.2 and described following.

Figure 2.2 Site Controller Controls and

Indicators

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controller.

Mode.

Controls & Indicators

Ethernet Link Status

This indicates the main Ethernet link data rate. If this LED is on, the rate is 100 Mbps. If this LED is off,

Reset Switch

Pressing this switch resets the controller card.

the rate is 10 Mbps.

2.2 Channel Controller Card

The channel controller card controls either a single t raf fic chann el or a single control channel for a particular 3800
repeater system. The Channel Controller card’s controls and indicators are illustrated in Figure 2.3 and described
following.

Figure 2.3 Channel Controller Card Controls and Indicators

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Controls & Indicators

Channel Controller Controls and Indicators

Ethernet Link Data Rate LED

This indicates the main Ethernet link data rate. If this LED is on, the rate

Ethernet Status LED

If on, the repeater is connected to Ethernet.

Reset Switch

Pressing this switch resets the channel controller card.

is 100 Mbps. If this LED is off, the rate is 10 Mbps.

Note Both of the Channel Controller card LEDs should be ON continuously after you initialize the repeater.

(Two LEDs are not used in the field.)

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