Guardian G25AMK005 User manual

G25AMK005
G25AMK005
GUARDIAN 110W MOBILE RADIO
TECHNICAL MANUAL
Datron World Communications Inc. 3030 Enterprise Court
Manual Part No. G25AMK005 Vista, CA 92083, USA
Release Date: May 2002 Phone: [phone] Fax: [phone]
Revision: A E-mail: [e-mail]
www.dtwc.com

GUARDIAN VHF 110W MOBILE i
2000 Datron World Communications Inc. All Rights Reserved.
GuardianTM Technical Manual for use with the Guardian 110W mobile radio.
This manual, as well as the software described in it, are furnished under license and may only be
used in accordance with the terms of such license. This manual is furnished for informational
use only, is subject to change without notice, and should not be construed as a commitment by
Datron World Communications Inc. Datron assumes no responsibility or liability for any errors
or inaccuracies that may appear in this manual.
Except as permitted by such license, no part of this publication may be reproduced, stored in a
retrieval system, or transmitted, in any form or by any means—electronic, mechanical,
recording, or otherwise—without the prior written permission of Datron World Communications
Inc.
GuardianTM is a trademark of Datron World Communications Inc.
Written and designed at Datron World Communications Inc., 3030 Enterprise Court, Vista,
California 92083 USA.
For defense agencies: Restricted Rights Legend. Use, reproduction, or disclosure is subject to
restrictions set forth in subparagraph (c)(1)(ii) of the Rights in Technical Data and Computer
Software clause at 252.227-7013.
For civilian agencies: Restricted Rights Legend. Use, reproduction, or disclosure is subject to
restrictions set forth in subparagraphs (a) through (d) of the commercial Computer Software
Restricted Rights clause at 52.227-19 and the limitations set forth in Datron’s standard
commercial agreement for this software. Unpublished rights reserved under the copyright laws
of the United States.
The warranty is void if an unauthorized dealer opens or attempt maintenance on the radio.
Manual part number: G25AMK005. Specifications are subject to change without notice or
obligation.
This device made under license of one or more of the following US Patents: 5,164,986;
5,146,497; 5,185,795; 4,636,791; 4,590,473; 5,185,796; 5,148,482; 5,271,017; 5377229;
4,833,701; 4,972,460.
The IMBETM voice coding technology embodied in this product is protected by intellectual
property rights including patent rights, copyrights, and trade secrets of Digital Voice Systems,
Inc. The voice coding technology can only be used as part of the North American land mobile
radio communications system for the APCO Project 25. The user of this technology is explicitly
prohibited from attempting to decompile, reverse engineer, or disassemble the Object Code, or in
any other way convert the Object Code into human-readable form.
Made in the USA

ii GUARDIAN VHF 110W MOBILE
NOTICE TO USER
WARNING! Maintain a distance of at least 3 feet (1 meter) between the antenna
and people.
To satisfy RF exposure compliance, you, as a qualified user of this radio device
must control the exposure conditions of bystanders to ensure the minimum
distance is maintained between the antenna and nearby persons. The operation
of this transmitter must satisfy the requirements of the Occupational/Controlled
Exposure Environment for work-related use. Transmit only when people are at
least the minimum distance from the properly installed, externally mounted
antenna.
This radio is designed for initial setup by authorized technicians using a
computer and the GuardianTM programming software. Programming can enable
or disable many of the radio’s features from user access per user agency
security policy and legal restrictions. All, some, or none of the features and
functions described in this manual may be available to the user. To successfully
operate the radio, it is important to understand how the radio is programmed
prior to issuance by the user agency. Consult authorized agency personnel for
features and functions made available or restricted to the user. FCC licensees
are prohibited by federal law from enabling the radio to directly enter transmit
frequencies using the radio's controls.
NOTICE TO INSTALLATION TECHNICIANS
Use only a manufacturer- or dealer-supplied antenna.
Antenna minimum safe distance: 3 feet (1 meter).
The Federal Communications Commission (FCC) has adopted a safety
standard for human exposure to Radio Frequency (RF) energy that is below
the Occupational Safety and Health Act (OSHA) limits.
Antenna mounting: The antenna supplied by the manufacturer or radio
dealer must be mounted at a location so that during radio transmission
people cannot come closer than the minimum safe distance to the antenna,
i.e., 3 feet (1 meter).
To comply with current FCC RF exposure limits, the antenna must be
installed at or exceeding the minimum safe distance, and in accordance
with the requirements of the antenna manufacturer or supplier.
Base station installation: The antenna should be fixed-mounted on an
outdoor permanent structure. Address RF exposure compliance at the time
of installation.
Antenna substitution: Do not substitute any antenna for the one supplied or
recommended by the manufacturer or radio dealer. You may be exposing
people to harmful RF radiation. Contact your radio dealer or manufacturer
for further instructions.

GUARDIAN VHF 110W MOBILE iii
CONTENTS
CHAPTER 1: GENERAL INFORMATION ................................................................................................. 1-1
1.1 SCOPE ......................................................................................................................................................... 1-1
1.2 GENERAL DESCRIPTION .............................................................................................................................. 1-1
1.3 PERFORMANCE SPECIFICATIONS ................................................................................................................. 1-1
CHAPTER 2: HARDWARE THEORY OF OPERATION.......................................................................... 2-1
2.1 INTRODUCTION ........................................................................................................................................... 2-1
2.2 SYSTEM SPECIFICATIONS ............................................................................................................................ 2-1
2.3 SYSTEM BLOCK DIAGRAM .......................................................................................................................... 2-2
2.4 RECM CONTROL HARDWARE THEORY OF OPERATION.............................................................................. 2-4
2.4.1 Control Logic ..................................................................................................................................... 2-4
2.4.2 DSP .................................................................................................................................................... 2-7
2.4.3 Flash ROM......................................................................................................................................... 2-7
2.4.4 RAM .................................................................................................................................................. 2-7
2.4.5 TCXO................................................................................................................................................. 2-7
2.4.6 FPGA ................................................................................................................................................. 2-8
2.4.7 IF ADC............................................................................................................................................... 2-8
2.4.8 Clock Generation ............................................................................................................................... 2-8
2.4.9 Logic Audio CODEC......................................................................................................................... 2-8
2.4.10 Accessory Connector Interface and Filtering .....................................................................................2-8
2.4.11 Transceiver Interface and Filtering .................................................................................................... 2-8
2.4.12 Keypad Interface ................................................................................................................................ 2-8
2.4.13 Audio Interface................................................................................................................................... 2-8
2.4.14 Test Interface...................................................................................................................................... 2-9
2.4.15 LED.................................................................................................................................................... 2-9
2.4.16 RECM Power Consumption............................................................................................................... 2-9
2.5 RECM TRANSCEIVER SECTION .................................................................................................................. 2-9
2.5.1 Interface Section................................................................................................................................. 2-9
2.5.2 Receiver Section............................................................................................................................... 2-10
2.5.3 Digital/Analog Control..................................................................................................................... 2-13
2.5.4 Keypad Microcontroller ................................................................................................................... 2-14
2.6 AUDIO AMPLIFIER BOARD ........................................................................................................................ 2-14
2.6.1 Description ....................................................................................................................................... 2-14
2.6.2 Power Conditioning ......................................................................................................................... 2-14
2.6.3 Communication with Transceiver .................................................................................................... 2-15
2.6.4 Audio Amplifiers ............................................................................................................................. 2-15
2.6.5 Power Levels Detector, Converter, and RF/DC Combiner .............................................................. 2-15
2.6.6 PA ON/OFF Control (Bypass Mode)............................................................................................... 2-16
2.6.7 RF Power Indication ........................................................................................................................ 2-16
2.6.8 Audio Board Block Diagram............................................................................................................ 2-16
2.7 DISPLAY BOARD ....................................................................................................................................... 2-17
Figure 2-4: Guardian Keypad Board............................................................................................................... 2-17
2.7.1 Control Logic Interface .................................................................................................................... 2-18
2.7.2 Keypad ............................................................................................................................................. 2-18
2.7.3 Switch Interface ............................................................................................................................... 2-18
2.8 FRONT PANEL INTERFACE BOARD ............................................................................................................ 2-18
CHAPTER 3: SOFTWARE THEORY OF OPERATION ........................................................................... 3-1
3.1 FUNCTIONAL SYSTEM OPERATION.............................................................................................................. 3-1
3.1.1 General............................................................................................................................................... 3-1
3.1.2 Guardian Block Diagram ................................................................................................................... 3-1
3.1.3 Architecture........................................................................................................................................ 3-2
3.1.4 Board Identification ........................................................................................................................... 3-2

iv GUARDIAN VHF 110W MOBILE
3.1.5 Self-Test on Power-Up....................................................................................................................... 3-2
3.1.6 Flash Software Upgrades ................................................................................................................... 3-2
3.1.7 Voice Coder/Decoder (VOCODER) .................................................................................................. 3-2
3.2 RADIO CONTROL SOFTWARE ...................................................................................................................... 3-2
3.2.1 Audio Control .................................................................................................................................... 3-2
3.2.2 DSP Control Software........................................................................................................................ 3-2
3.2.3 Transceiver Board .............................................................................................................................. 3-3
3.2.4 DC Power Control.............................................................................................................................. 3-5
3.2.5 Monitoring ......................................................................................................................................... 3-5
3.2.6 Radio Control Drivers ........................................................................................................................ 3-5
3.3 DIGITAL SIGNAL PROCESSING..................................................................................................................... 3-6
3.3.1 DSP Transmit Chain .......................................................................................................................... 3-6
3.3.2 DSP Receive Chain ............................................................................................................................ 3-8
3.3.3 DSP Software................................................................................................................................... 3-11
3.4 KEYPAD MPU SOFTWARE ........................................................................................................................ 3-11
3.4.1 Overview.......................................................................................................................................... 3-11
3.4.2 General............................................................................................................................................. 3-11
3.4.3 Keypad Scanning ............................................................................................................................. 3-11
3.4.4 Push-to-Talk (PTT) Input................................................................................................................. 3-11
3.4.5 Switch Input ..................................................................................................................................... 3-11
3.4.6 LED Output...................................................................................................................................... 3-11
3.4.7 Backlight Control............................................................................................................................. 3-11
3.4.8 Serial Interface ................................................................................................................................. 3-11
3.5 DATA INTERFACE...................................................................................................................................... 3-12
3.5.1 CAI Data Interface ........................................................................................................................... 3-12
3.5.2 Synchronous Serial Data Interface................................................................................................... 3-12
3.5.3 CAI Data Link Layer ....................................................................................................................... 3-12
3.5.4 Transmit Physical Link Layer .......................................................................................................... 3-13
3.5.5 Receive Physical Link Layer............................................................................................................ 3-14
3.5.6 DES Encryption ............................................................................................................................... 3-14
3.5.7 Host Interface................................................................................................................................... 3-15
3.5.8 Flash Interface.................................................................................................................................. 3-15
3.5.9 Paging............................................................................................................................................... 3-15
3.5.10 Hardware Control............................................................................................................................. 3-16
3.6 CONTROLLER SOFTWARE.......................................................................................................................... 3-16
3.6.1 Overview.......................................................................................................................................... 3-16
3.6.2 Environment..................................................................................................................................... 3-16
3.6.3 Radio Store....................................................................................................................................... 3-18
3.6.4 Program/Fill/Control Interface......................................................................................................... 3-19
3.7 USER INTERFACE ...................................................................................................................................... 3-20
3.7.1 Display ............................................................................................................................................. 3-20
3.7.2 Optional DTMF Microphone ........................................................................................................... 3-20
CHAPTER 4: INSTALLATION, ADJUSTMENT, AND OPERATION .................................................... 4-1
4.1 RADIO CONFIGURATION ............................................................................................................................. 4-1
4.1.1 Channels............................................................................................................................................. 4-1
4.1.2 Zones.................................................................................................................................................. 4-1
4.1.3 Banks.................................................................................................................................................. 4-1
4.2 INSTALLATION AND ADJUSTMENT .............................................................................................................. 4-1
4.2.1 Hardware............................................................................................................................................ 4-1
4.2.2 Software ............................................................................................................................................. 4-1
4.3 OPERATING PROCEDURES ........................................................................................................................... 4-1
4.3.1 Connect the Power Source ................................................................................................................. 4-1
4.3.2 Connect the Antenna .......................................................................................................................... 4-1
4.3.3 Optional External Speaker ................................................................................................................. 4-1
4.3.4 Radio Programming ........................................................................................................................... 4-1

GUARDIAN VHF 110W MOBILE v
4.3.5 Radio Power Up ................................................................................................................................. 4-2
4.3.6 Choose a Channel............................................................................................................................... 4-2
4.3.7 Transmit a Voice Message ................................................................................................................. 4-2
4.3.8 Receive a Voice Message................................................................................................................... 4-2
4.3.9 Programming and Bypass Mode ........................................................................................................ 4-2
CHAPTER 5: RADIO SET AND ACCESSORIES ....................................................................................... 5-1
5.1 SYSTEM DESCRIPTION ................................................................................................................................5-1
5.1.1 Mobile Radio...................................................................................................................................... 5-1
5.1.2 Antenna .............................................................................................................................................. 5-1
5.1.3 Guardian PC Programmer .................................................................................................................. 5-1
5.1.4 Cloning Cable..................................................................................................................................... 5-2
5.2 CONTROLS, INDICATORS, AND CONNECTORS ............................................................................................. 5-2
5.2.1 Controls.............................................................................................................................................. 5-2
5.2.2 Indicators............................................................................................................................................ 5-3
5.2.3 Connectors ......................................................................................................................................... 5-4
5.3 TRANSCEIVER CHARACTERISTICS ............................................................................................................... 5-4
5.3.1 Transmitter Characteristics ................................................................................................................ 5-4
5.3.2 Receiver Characteristics..................................................................................................................... 5-5
5.4 COMMUNICATION SECURITY ...................................................................................................................... 5-5
5.4.1 Algorithms ......................................................................................................................................... 5-5
5.4.2 Keyfill ................................................................................................................................................ 5-5
5.4.3 Zeroize ............................................................................................................................................... 5-6
CHAPTER 6: SERVICING THE RADIO...................................................................................................... 6-1
6.1 GENERAL .................................................................................................................................................... 6-1
6.2 SELF-TEST AT POWER UP........................................................................................................................... 6-1
6.3 CAUTION..................................................................................................................................................... 6-1
CHAPTER 7: TROUBLESHOOTING........................................................................................................... 7-1
7.1 INTRODUCTION ........................................................................................................................................... 7-1
7.2 RADIO FUNCTIONAL TESTS......................................................................................................................... 7-1
7.2.1 Power-On Test ................................................................................................................................... 7-1
7.2.2 Buttons and Switches Test ................................................................................................................. 7-1
7.2.3 Transmit Test ..................................................................................................................................... 7-1
7.2.4 Receive Test....................................................................................................................................... 7-1
7.2.5 Audio Test.......................................................................................................................................... 7-1
CHAPTER 8: DEFINITIONS ......................................................................................................................... 8-1
CHAPTER 9: SIGNAL TONES...................................................................................................................... 9-1
CHAPTER 10: INTERFACE ...............................................................ERROR! BOOKMARK NOT DEFINED.
10.1 ACCESSORY CONNECTOR PINS AND FUNCTIONS....................................................................................... 10-1
CHAPTER 11: SCHEMATICS....................................................................................................................... 11-1
FIGURES
Figure 2-1: Guardian Interconnect Diagram .............................................................................................................2-3
Figure 2-2: Guardian Control Logic .........................................................................................................................2-4
Figure 2-3: RECM Power Supply .............................................................................................................................2-5
Figure 2-4: Guardian Keypad Board.......................................................................................................................2-17
Figure 3-1: Guardian Block Diagram........................................................................................................................3-1
Figure 3-2: Transmit DSP Chain...............................................................................................................................3-7
Figure 3-3: Receive DSP Chain ................................................................................................................................3-8
Figure 3-4: Controller Software ..............................................................................................................................3-16

GUARDIAN VHF 110W MOBILE 1-1
CHAPTER 1: GENERAL INFORMATION
1.1 Scope
This manual provides technical information for the Guardian 110 Watt mobile radio system.. This chapter gives a
general description and provides a system block diagram. Chapters 2 and 3 provided detailed theory of operation for
hardware and software portions of the radio. Chapter 4 provides general operation of the radio. Chapter 5 is the
physical description of the radio components and the available accessories. Chapters 6 and 7 describe servicing,
testing, and troubleshooting the radio system. The remaining chapters provide additional technical information and
schematics.
1.2 General Description
The Guardian 110W mobile radio system is compliant with the APCO project 25 FDMA common air interface, and
is also compatible with conventional wideband FM systems and newer narrowband FM systems. It provides fully
digital encrypted communication suitable for use by modern public safety and commercial users. The radio system is
built from a remote power amplifier and a control head. The 110W RF power amplifier mounts in a remote location
such as a vehicle trunk, while the control unit is mounted in the cabin. The two are connected by a single coaxial
cable. The cable carries both the RF signal and control signals (PTT, and power level setting).
1.3 Performance Specifications
Model Designation Guardian VHF Mobile Radio
General Model G25RMV110
Frequency Range 136.000 to 174.000 MHz
Banks, Zones, Channels, Shadow 4 banks, 16 zones, 256 channels, 7 shadow
Voice Digital Mode Voice Coding
Frame Re-sync Interval
Error Correction Method
IMBE™ 4.4 kb
180 msec
RS, golay, hamming
Input Voltage 13.6 Vdc, negative chassis ground
Current Drain @ 13.8V: Standby
Receive @ Rated Audio
Transmit @ Rated Power
0.5A
3.0A
28.0A
Mounting Dashboard mounted, including bracket
Dimensions 2.75” x 7.1” x 5.5” (H x W x D)
Weight
Control Head
Remote Unit
2.5 lb
12 lb
Case Metal and plastic
Temperature Range -30° to +60°C
Channel Spacing 12.5 and 25 kHz, selectable in 2.5 or
3.125 kHz steps
FCC Type Acceptance Number Pending
Industry Canada Pending

1-2 GUARDIAN VHF 110W MOBILE
Model Designation Guardian VHF Mobile Radio
Receiver (Measurements per TIA/EIA 603 Standards)
Sensitivity Digital Mode: 5% BER
Analog Mode: 12 dB SINAD
-116 dBm or greater
Spurious -70 dB
Intermodulation -70 dB
Audio Output Power 10W, 4Ωexternal, 5W, 8Ωinternal speaker
Audio Distortion (at 1000 Hz) 3%
Frequency Stability (-30° to 60°C) ± 1 ppm
Maximum Frequency Separation Full-band split
Transmitter (Measurements per TIA/EIA 603 Standards)
RF Power Output 25W to 110W, adjustable
Spurious and Harmonic Emissions -70 dB
FM Hum and Noise (wideband) -46 dB @ 25 kHz/-40 dB @ 12.5 kHz
FCC Modulation Designators 16K0F3E, 11K0F3E, 20K0F1E
Audio Distortion (at 1000 Hz) 2%
Audio Response (1000 Hz Ref.) ± 3 dB, 300 to 3000 (EIA/TIA 603)
Frequency Stability (-30°C to 60°C) ± 2.5 ppm
Maximum Frequency Separation Full bandwidth
Environment Specifications (MIL-SPEC)
Environment 810C 810D 810E
Method Procedure Method Procedure Method Procedure
Low Pressure 500.1 I 500.2 I 500.3 II
High Temp. 501.1 I, II 501.2 I, II 501.3 I, II
Low Temp. 502.1 I 502.2 I 502.3 I
Temp. Shock 503.1 I 503.2 I 503.3 I
Solar Radiation 505.1 I 505.2 I 505.3 I
Humidity 507.1 II 507.2 II (5) 507.3 II (5)
Salt Fog 509.1 I 509.2 I 509.3 I
Dust and Sand 510.1 I 510.2 I 510.3 I, II
Vibration 514.2 VII(W) 514.3 I (1) 514.4 I (1)
Shock 516.2 I, II, V 516.3 I 516.4 I

GUARDIAN VHF 110W MOBILE 2-1
CHAPTER 2: HARDWARE THEORY OF OPERATION
2.1 Introduction
The Control Module contains the Receiver Exciter Control Module (RECM), Audio amplifier
board, Interface board, and display and keypad assemblies. The RECM is a shielded assembly
containing the transceiver and all control and signal processing hardware and firmware, except
the RF and audio power amplifiers. The trunk-mounted RF power amplifier contains a single PC
assembly.
Schematics for all the boards are located in the back of the manual.
2.2 System Specifications
Table 2-1: Guardian G25RMV110 Technical Specifications
Specification Description
General
Frequency Range 136.000 to 174.0000 MHz
Banks, Zones, Channels, Shadow 4 banks, 16 zones, 256 channels, 7 shadow
Voice Digital
Mode Voice Coding IMBE4.4 kb
Frame Re-sync Interval 180 msec
Error Correction Method RS, golay, hamming
Mounting Under dashboard using bracket
Dimensions 2.94”x7.13”x7.06” (H x W x D)
Weight 5 lbs. Approximately
Case Metal and plastic
Temperature Range -30°to +60°C
Channel Spacing 12.5 and 25 kHz, selectable in 2.5 or 3.125 kHz steps
FCC Type Acceptance Number Pending
Industry Canada Pending
Receiver (Measurements per TIA/EIA 603 Standards)
Sensitivity
Digital Mode: 5% BER
Analog Mode: 12 dB SINAD
-116 dBm maximum
Spurious -70 dB
Intermodulation -70 dB
Audio Output Power 5W internal, 10W external speaker
Audio Distortion (at 1000 Hz) 5%
Frequency Stability (-30°to +60°C) ±2.5 ppm
Maximum Frequency Separation Full-band split
Transmitter (Measurements per TIA/EIA 603 Standards)
Duty Cycle 3%, 3 min continuous
RF Power Output 25W, 50W, 110W; also bypass mode
Spurious and Harmonic Emissions -70 dB
FM Hum and Noise (wide/narrowband) -48/-47 dB typical
FCC Modulation Designators 11K0F3E, 16K0F3E, 22K0F3E, 14K6F1E
Audio Distortion (at 1000 Hz) 5%
Audio Response (1000 Hz Ref.) ±3 dB 300 to 3000 (EIA/TIA 603)
Frequency Stability (-30°to +60°C) ±2.5 ppm

2-2 GUARDIAN VHF 110W MOBILE
Specification Description
Maximum Frequency Separation Full bandwidth
DES Encryption
Encryption Keys 16
Code Key Generator External
SBCF Analog DES Encryption Standard feature
Environmental Specifications MIL-STD-810F
Test Method/Procedure
Low Pressure (Altitude) 500.4/II
High Temperature 501.4/I, II
Low Temperature 502.4/I
Temperature Shock 503.4/I
Solar Radiation (Sunshine) 505.4/I
Humidity 507.4/I
Salt Fog 509.4/I
Sand and Dust 510.4/I, II
Vibration 514.5/I
Shock 516.5/I
Standard Accessories Optional Accessories
5W Internal Speaker 10W External Speaker
Palm Microphone DTMF Microphone
Mounting Bracket Key Variable Loader
14 ft Power Cable 25 ft Power Cable
2.3 System Block Diagram

GUARDIAN VHF 110W MOBILE 2-3
Control Head
Mounted Power Amplifier
Coax
Control
Cable
Antenna ConnectionIn/Out
Fused DC Cable
Power ON/OFF and R/T
switches
Control
Power
spliter
output power
control monitor
Filter&
combiner
AMP
AMP
power sensor
R
R
T
T
Fused DC Power
DB9
Speaker out
Ignition and Emergency Switch
DB25
System Control and
Programming
RECM
PA
control
Front panel interface
(LCD,Keypad and switches)
MIC
connector
DTMF
control
DC
connector
Figure 2-1: Interconnect Block Diagram

2-4 GUARDIAN VHF 110W MOBILE
2.4 RECM Control Hardware Theory of Operation
2.4.1 Control Logic
The control logic interfaces to the keypad logic, transceiver, internal audio, and Motherboard. The control logic
implements the main radio control function and all the baseband signal processing.
TCVR Module
DB25 Accessory Connector
Power Supply
Keypad Board and Front Panel Interface
Grey areas connect
through the 80-pin
connector on the
Motherboard.
Figure 2-2: Guardian Control Logic
2.4.1.1 Power Supply Unit
This block of circuitry takes the 7.8V regulated voltage together with a number of control signals to generate a
number of power supply outputs.

GUARDIAN VHF 110W MOBILE 2-5
2.4.1.2 On/Off Switching
The main continuous supply 10V control is passed through a front panel on/off switch to generate 10V SW from the
main radio supply. In normal operation the on/off switching is controlled by the radio on/off rotary switch by the
control /RADON. Once switched on the main controller can hold the radio on by setting PWRHOLD. In addition
to the radio rotary on/off switch, the on/off switching can be controlled by the external line /RADOFF via the
accessory connector. This line overrides the /RADON line and can be used to force the radio off regardless of the
rotary switch setting. However, the H8 controller uses the PWRHOLD and PWROFF lines to implement a clean
controlled switch off.
Figure 2-3: RECM Power Supply
2.4.1.3 Transmit Power Switching
A single FET switch controlled by CTX is used to provide a switched 10VTX high-current supply (1.5A) for the
transmitter.
2.4.1.4 4.5V Switch Mode Power Supply
This circuit uses a switch mode power supply device to generate a 4.5V supply at 450 mA maximum for the radio
logic. The switch mode device is synchronous and uses an externally provided power supply clock at 384 kHz. The
power supply circuit includes input and output filters to limit the conduction of the fundamental switching
components and their harmonics in the VHF band, both onwards into the logic and back into the power supply.

2-6 GUARDIAN VHF 110W MOBILE
2.4.1.5 3.3V Linear Logic Supply
The output from the 4.5V switch mode power supply is passed through 3.3V linear power supplies to remove any
remaining power supply switching noise on the main logic supply. One 3.3V supply is used for control logic, the
other 3.3V, 50 mA supply is used for control logic analog circuitry.
2.4.1.6 Reset Generator
This circuit uses a MPU supervisory device (MAX825) to generate a reset pulse of at least 140 ms whenever the
3.3V logic supply drops below 3.08V. The circuit also generates a reset signal when the watchdog input is asserted
by H8 or DSP.
2.4.1.7 5V Linear Logic Supply
This circuit generates a 5V logic supply at 50 mA maximum for use on the control logic.
2.4.1.8 Audio Supplies
Two linear regulators providing clean filtered supplies for the audio at 5V are provided. The audio power amplifiers
use the 5V, 800 mA audio supply. The audio supply is used for the low-current microphone amplifier. A linear 5V
bias supply to the internal microphone is also provided.
2.4.1.9 H8 Microcontroller
H8 is the main controller for the radio and is a HD6433044 ROM-less microcontroller. H8 is configured with an
expanded bus connected to the Flash, RAM, and DSP. The H8 integral bus arbitration logic allows H8 and DSP to
both have access to the Flash and RAM. H8 is clocked by the external TCXO.
H8 is powered from the 3.3V logic supply, and reset by the hardware /RES line. A watchdog output to the hardware-
reset circuitry is provided. H8 generates chip select outputs to allow the Flash, RAM, FPGA, and DSP host port to
be separately addressed.
One serial port of H8 is used to implement a bidirectional synchronous serial interface to the keypad board. This
interface is used to communicate with the keypad MPU and directly load the LCD controller. The clock on this
interface runs at 100 kHz. An associated interrupt input to H8 is used to initiate transfers from the keypad to H8.
This serial interface is also used to load the output expander in the FPGA, and also to configure the FPGA.
One serial port of H8 is used to implement a bidirectional asynchronous serial interface to an external PC used for
programming, filling, and controlling the radio. This interface uses programmable standard baud rates (default 9600
baud) and standard data formats. There are no handshaking parallel lines associated with this interface. Two parallel
I/O lines on H8 are used to generate an I2C interface to allow the EEPROM on the transceiver to be accessed. Four
parallel output lines on H8 are used to generate a synchronous serial output bus with clock and data and separate
strobe lines for the DAC, control shift register, and synthesizer on the transceiver.
One H8 DAC output is used to generate simple audio tones of varying volume for use as audio alerts. The second
H8 DAC output is available for VCTCXOP control. The six-channel ADC is used to measure: the raw supply
voltage, WRU radio input, reference crystal temperature, PA temperature, PA current, and RSSI. Two I/O lines are
used to implement software UART, used for debug outputs in the development environment.
2.4.1.10 H8 Input Requirements
The total requirements for parallel input signals to H8, which need to be polled on a regular basis are:
 OOL: Out-of-lock (OOL) signal from the transceiver synthesizer
 EXT PTT: External PTT
 PWROFF: On/off switch position
 CONFDONE: Configuration status of FPGA
2.4.1.11 H8 Output Requirements
The total requirements for parallel output signals from H8, which need to be controlled are as below. A serial load
output latch in the FPGA expands the output capabilities of H8.

GUARDIAN VHF 110W MOBILE 2-7
 LCDA0: LCD controller A0 command/ data select
 LCDCS: LCD chip select
 SCL: I2C and synthesizer clock
 DACSDA: Transceiver serial data, synthesizer, DAC, S-R
 SYNTHENA: Synthesizer framing pulse
 DACENA: DAC framing pulse
 SRENA: S-R framing pulse
 /DINT: Interrupt to DSP from H8
 /RESO: Watchdog output from H8
2.4.1.12 H8 Input/Output Requirements
The total requirements for parallel input/output signals on H8, which need to be read and controlled are:
 BATBUS: Not used in the mobile configurations
 SDA: I2C data
2.4.1.13 H8 Input Interrupt Requirements
The total requirements for parallel input interrupt signals on H8 are:
 LBOUT: Not used in the mobile configuration
 DSPINTDSP: Interrupt
2.4.2 DSP
The DSP56309 (or DSP56302) processor implements all baseband signal-processing functions in the radio. It
interfaces with the transceiver through one ESSI port, to the user for voice through the second ESSI port. The DSP
function is controlled by H8 through the DSP host port. The DSP has direct access to the main Flash memory
through the bus arbitration logic in H8, this allows it to download program images. The initial power-on code
download is through the host port. The hardware-reset line resets the DSP. The TCXO clock output line clocks the
DSP at 12.288 MHz. The DSP ESSI 1 port is used to provide a synchronous interface to the IF ADC and the
transceiver 12-bit DAC. In receive modes that interface is capable of writing to the DAC at 48 ksps while still
reading the ADC at 96 ksps. The DSP ESSI “0” port is used to provide a full-duplex synchronous interface to the
audio CODEC using 8 kHz sampling rate and 13 bit samples. The data transfer is at 2.048 MHz using a DSP
sourced clock and framing pulse.
2.4.3 Flash ROM
A 512k x16 Flash ROM is used as the main program store for the H8 controller and DSP. The Flash ROM uses a
protected boot sector that is factory programmed via the DSP JTAG port. Normal reprogramming is implemented
by running H8 from the boot sector and using 3V, programming the bulk of the device. The Flash is used to provide
a parameter storage area for nonvolatile data storage of frequencies and keys, etc. This storage area is capable of in
excess of 100k write cycles.
2.4.4 RAM
A 128k x 8 static RAM is used for temporary storage of data by the H8 controller. This RAM is powered by a
continuous supply that maintains its contents as long as a power source is present. Additionally the RAM has a
backup capacitor to retain its contents over power interruptions.
2.4.5 TCXO
This oscillator serves as the reference for all logic and power supply clocks within the control logic and keypad. It
provides the data rate clocks for radio operation, and is the source of the ADC/DAC/CODEC conversion clocks. The
TCXO is at 12.288 MHz, with a temperature tolerance of +2.5 ppm. Additional calibration is performed to provide
a typical temperature tolerance of ± 1.0 ppm, a trimmer to set the initial frequency is provided. A Schmitt trigger
buffer squares up the TCXO sine wave output before being output to H8 and DSP.

2-8 GUARDIAN VHF 110W MOBILE
2.4.6 FPGA
The control logic uses an Altera 8282 FPGA device to provide a flexible serial data routing function, I/O expansion
for H8 and DSP, clock generation, data multiplexing, and to absorb discrete logic functions.
The synchronous serial bus routing function involves routing the synchronous serial port of H8 either to the keypad
and LCD, or to the I/O expansion in the FPGA. High-order address pins from H8 control this routing and a FPGA
dummy write with dedicated FPGA chip select from H8. The FPGA includes a serial load parallel output shift
register that is used for parallel output expansion for H8.
The discrete logic functions of the FPGA, includes logic to control an inverter for one of the LCD control outputs.
The data multiplexing function involves rerouting serial pins between the accessory connector and the DSP SCI port
to allow data transmission and keyfill operations.
2.4.6.1 FPGA Configuration
The FPGA is configured at start-up from the main Flash memory using a serial load from H8. During configuration
outputs are tri-stated and pulled to a safe level by committing resistors to prevent audio and RF bursts at power up.
2.4.7 IF ADC
The IF sampling ADC is a 12-bit ADC capable of sub-sampling a 455 kHz, IF signal at 96 kHz sampling rate. It is
connected by a serial interface to the DSP ESSI port 1. The serial data interface is clocked at 1536 kHz.
2.4.8 Clock Generation
The clock generation logic is used to generate clocks for the synchronous power supplies, the ADC serial interface,
and the keypad microcontroller. The clock generator logic is implemented in the FPGA.
2.4.9 Logic Audio CODEC
The audio CODEC is an integrated ADC/DAC and audio filter device capable of full-duplex operation on voice
bandwidth signals at 8 ksps. The samples have a resolution of 13-bits linear. The CODEC is connected to the DSP
ESSI port “0” with serial data transfer rate of 2.048 MHz. The CODEC is continuously powered from the 3V logic
and 3V audio supplies. DSP parallel control lines are used to mute the input and output sections as required.
2.4.10 Accessory Connector Interface and Filtering
All outputs are filtered to limit their bandwidth to the minimum and current limited to protect them from output
short circuits to ground or up to 16V. All inputs are filtered and protected from continuous application of ground or
+16V. There is no protection against negative applied voltages. Inputs and outputs are protected from static
discharge of at least 10 kV air discharge. All inputs and outputs incorporate RF bypass filter capacitors adjacent to
the connector, except for ground.
2.4.11 Transceiver Interface and Filtering
Most of the signals crossing the interface are filtered to limit their bandwidth to the minimum consistent with correct
operation. Outputs from the control are filtered with series resistors on the RECM and grounded capacitors on the
transceiver adjacent to the connector. Outputs from the transceiver to the control use the reverse configuration.
2.4.12 Keypad Interface
Some filtering is provided on this interface, but all outputs are protected from short circuits by series resistors.
Where possible, inputs are also protected from damage by series resistors.
2.4.13 Audio Interface
The audio interface is implemented with four-way wire connectors directly via the 80-pin interface through the
Motherboard to the integral speaker and microphone.

GUARDIAN VHF 110W MOBILE 2-9
2.4.14 Test Interface
The test interface provides the following functions:
 Joint test action group (JTAG) connector access for board test and Flash boot sector programming
 Board reset and control access
 Board power supply and on-off switching access
 H8 serial debug port access
2.4.15 LED
The control logic incorporates a 3-color LED used for status information. It is controlled by the FPGA to show red,
green, or off. It is optically coupled to the top face of the radio by a light pipe. The hardware is configured so
during hardware reset, before the keypad MPU software is running, the LEDs are off.
2.4.16 RECM Power Consumption
The control logic operates at input voltage 7.7V. The average current consumption of the control logic is:
 Standby mode: 60 mA
 Receive mode @ 500 mW: 330 mA
 Transmit mode @ 2W: 1,000 mA
 Transmit mode @ 5W: 1,500 mA
2.5 RECM Transceiver
RF shields covers the board.
2.5.1 Interface
J2 is the transceiver antenna connector. RF signals are transmitted and received through this surface mount RF
connector. Transmitted and received RF signals are routed from this connector through a short RF cable to the
RX/TX relay on the Motherboard.
2.5.1.1 Transmit Chain
The pre-driver amplifier (Q7, etc.) amplifies the TXLO signal from the synthesizer section. The Q7 output power is
typically 13 dBm measured at C77/R44/R49 node.
R44, R49, and R52 are part of a 3 dB pie attenuator network. The gain control is made up of CR5, CR6, and
associated components. This circuit yields more than 50 dB of useful attenuation range. The circuit is part of a
DAC controlled closed loop system, in conjunction with the detector/power control circuit (U12, U13, and
associated components), which controls the transmitter output power level. The power amplifier (PA) is a
Mitsubishi M68776, 7.2V, 6W gained controlled power amplifier.
The harmonic filter (C209, L30, C81, C82, L31, C83, and C84) attenuates harmonics created by the power
amplifier. The harmonic filter insertion loss is 0.4 dB typically at 174 MHz. The output of the harmonic filter
connects to the 20 dB coupler (U12). This coupler is part of a DAC-controlled closed loop system designed to set
the transmitter output power level. The insertion loss through the coupler (U12-1 to U12-3) is 0.2 dB typically.
2.5.1.2 Power Amplifier Control
Transmit output power level is controlled by the detector/power control circuit and the gain control amplifier input
via VCONTROL. This closed loop system is designed to keep the transmitter output power constant over variations
in temperature, transmitter supply voltage (7.5VT), and RF power levels into the transmit chain. The detector/power
control circuit is made up of the 20 dB coupler (U12), an RF rectifier circuit (CR11, CR12, etc.), and an integrator
(U13). The DAC line labeled PWRSET at the non-inverting input of U13 sets the transmitter to the desired power
level. U12-2 samples the transmit signal. The sampled RF signal is rectified by the temperature stable circuitry of
CR11, CR12, etc, and is routed to the inverting input of the integrator at U13-4. The output of the integrator at U13-
1, labeled VCONTROL, controls the gain of the power amplifier. Any change in transmitter output power level is
automatically corrected by the loop.

2-10 GUARDIAN VHF 110W MOBILE
2.5.1.3 PIN Diode Switch
The antenna PIN diode switch is made up of CR7, CR8, CR9, CR10, and other associated components. This switch
is a four-port design. The four ports are antenna 1 (TOP RF), antenna 2 (SIDE RF), receive, and transmit. Receive
and transmit ports can be switched to only one of the two antenna ports. Transmit signals are routed from the
transmit/receive PIN diode switch (to be discussed in the following paragraph) to the antenna port. The receive
signal is routed from the selected antenna port to the transmit/receive PIN diode switch. The antenna PIN diode
switch and receiver circuits share current in the receive mode of operation via the signal labeled RXSINK at Q11,
pin 3. The insertion loss through the antenna pin switch is 0.2 dB typically.
The transmit/receive PIN diode switch is made up of C6, L60, L38, L40, L39, D9, D7, D10, C97, C98, C104, C105,
C106, C107, and other associated components. C127, C114, L42, and C115 are the 1/4 wave simulator circuit. The
1/4 wave simulator is critical to the design of the switch. In the transmit mode of operation CR13 and CR14 are
forward biased. C116 resonates with the internal series inductance of CR14 at 155 MHz and the receive port (RX
INPUT) is RF shorted to ground. With the receive port RF shorted to ground; the parallel combination of C127,
C114, and L42 forms a tank circuit resonating at 155 MHz. Consequently, the receive port appears as an open
circuit to the transmit signal and is routed to the antenna PIN diode switch. In the receive mode of operation, CR13
and CR14 are biased off so C114/L42/C115 appears as a low-pass filter (LPF) to signals at the antenna port of the
switch. The insertion loss through the transmit/receive PIN diode switch is 0.4 dB in the transmit mode and 0.2 dB
in the receive mode typically.
Q10 to Q19 and associated components are switching transistors used to control the antenna and transmit/ receive
PIN diode switches. The current flowing through the entire PIN diode circuit is approximately 45 mA in the
transmit mode of operation. In the receive mode of operation the transmit/receive PIN diode switch is disabled, and
nominal 85 mA flows through the antenna PIN diode switch.
2.5.2 Receiver
The VHF signal enters into the RX INPUT via the PIN diode switch (discussed previously). D1 and D2 are
Schottky protection diodes to protect the front-end circuitry from RF overloads that could occur if the PIN diode
switch failed to work properly or if a transmitter is very close to a receiver. Typical insertion loss is 0.1 dB for the
protection diodes. L25/C61 form a band-stop filter (BSF) at the first IF frequency of 45 MHz. Typical insertion
loss for the BSF is 15 dB at 45 MHz but less than 0.1 dB in the VHF band.
L14, L6, CR3, CR4, L7, CR27, CR28, L8, and L15 make up the very high frequency (VHF) preselector band-pass
filter (BPF). The BPF is inductively coupled for improved high-side attenuation. This filter provides attenuation to
spurious signals such as the first image and the half-IF. The BPF is varactor diode tuned by DAC line RXVTF.
Typical insertion loss (138 to 174 MHz) is 1 dB for the VHF BPF.
The RF amplifier (Q1, T1, etc.) utilizes loss-less feedback to deliver reasonable gain, low-noise figure, and a high
third order intercept point simultaneously. Typical gain (136 to 174 MHz) is 11.5 dB for the RF amplifier.
C14, L1, C9, C15, L2, C10, C16, L3, C11, C17, and L9 form a VHF LPF. This filter provides additional RX
spurious attenuation as well as image noise attenuation. L4, C12, L16, C25, L5, and C13 form a BSF at the first IF
frequency of 45 MHz. The insertion loss is 1.0 to 2.0 dB (136 to 174 MHz) typically for the cascade. The IF BSF
insertion loss is typically 40 dB at 45 MHz, but less than 0.3 dB in the VHF band.
U1 is a double-balanced mixer (DBM). U1 converts the desired RF signal down to the first IF of 45 MHz. High-
side local oscillator (LO) injection is used. Therefore, the LO is 45 MHz higher than the receiver tuned frequency.
The LO drive level is +10 dBm nominal at U1, pin 1. The conversion loss of the mixer (RF to IF) is 5.5 dB
typically.
The LO signal is generated in the synthesizer section (to be discussed later). The LO signal is designated RXLO on
the schematic diagram. The LO signal is routed to a LPF consisting of C31, L21, C87, C30, L20, C75, and C28.
L19 and C28 are also used to impedance match the LO port of the mixer. The insertion loss of the VHF LO LPF is
0.3 dB typically at 174 MHz.
R4, L17, C6, L10, R5, and C23 make up the diplexer network. This network properly terminates the DBM both in
and out of band. The diplexer also provides some additional half-IF spurious rejection. The diplexer insertion loss
is 0.8 dB typically at 45 MHz.