Motorola Astro Digitalport Saber Detailed 68p81076c10 A Manual

2-2
Notations Used in 
This ManualThroughout the text in this publication, you will notice the use of 
warnings, cautions, and notes. These notations are used to emphasize 
that safety hazards exist, and care must be taken and observed.
NOTE:An operational procedure, practice, or
condition, etc., which is essential to
emphasize.
You will also find in this publication the use of the asterisk symbol (*) 
to indicate a negative or NOT logic true signal.
CAUTION: Indicates a potentially hazardous sit-
uation...

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General Overview of an 
ASTRO Digital SABER Radio
3
The ASTRO Digital SABER radio is a dual mode (trunked/
conventional), microcontroller-based transceiver incorporating a 
Digital Signal Processor (DSP). The microcontroller handles the 
general radio control, monitors status, and processes commands input 
from the keypad or other user controls. The DSP processes the typical 
analog signals and generates the standard signaling digitally to 
provide compatibility with existing analog systems. In...

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The display module is a two-line, liquid crystal display with associated 
circuitry. The display module is an integral part of the front cover 
keypad. This module utilizes chip-on-board technology and is not 
considered field repairable.
The available encryption module connects directly to the VOCON 
board and interfaces directly to the vocoder digital circuitry. It 
contains an independent microcontroller, and two custom ICs to 
perform digital, numerical, encryption algorithms.
Analog 
Mode of...

3-3
Transceiver Board 
OverviewThe receiver front end consists of a preselector, an RF amplifier, a 
second preselector, and a mixer. Both preselectors in the VHF and UHF 
radios are varactor-tuned, two-pole filters controlled by the 
microcontrol unit through the digital/analog (D/A) IC. On the 
800MHz receiver front end, these filters are fixed-tuned. The RF 
amplifier is a dual-gate, gallium- arsenide based IC. The mixer is a 
double-balanced, active mixer coupled by transformers. Injection is 
provided by...

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The SLIC acts as an extension of the microcontrol unit by providing 
logic functions such as lower address latch, reset, memory address 
decoding, and additional control lines for the radio. The microcontrol 
unit controls the crystal-pull circuit to adjust the crystal oscillator’s 
frequency on the microcontrol unit, so that the E-clock’ s harmonics 
do not cause interference with the radio’s receive channel.
Switched +5V is used for all circuits on the VOCON board except the 
audio PA, which is...

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Radio Power
4
IntroductionThis section of the manual provides a detailed circuit description of 
the power distribution for an ASTRO Digital SABER radio. 
GeneralIn the ASTRO radio, power is distributed to three boards: 
•transceiver 
•VOCON 
•display 
In the case of a secure model radio, the encryption module is supplied 
also. 
Power for the radio is provided through a battery supplying a nominal 
7.5Vdc directly to the transceiver. The battery is available in the 
following forms:...

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B+ Routing for 
VHF/UHF 
Transceiver BoardsRefer to Figure 1 and your specific schematic diagram.
Raw B+ (7.5V) from the battery (Batt B+) enters the radio on the 
transceiver board through a 3-contact spring pin arrangement (J3) as 
B+, where it is routed through two ferrite beads on the VHF (E1, E101) 
and three ferrite beads on the UHF (E1, E101, E106) to the RF power 
amplifier module (U105) and ALC IC (U101, pin 13). Battery B+ is 
fused, and then routed through the connector J1, pins 19 and 20 to...

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The SC3 signal at U102 pin 14 controls the Rx 5V switch U106, and 
the receive 5 volts (R5). A voltage on the synthesizer SOUT line at 
U204 pin 19 supplies power (Vcc) to the VCO buffer at U201 pin 3.
During the receive mode, regulator U106 supplies regulated 5V (R5) to 
the receiver front end. In the battery-saver mode, R5 can be switched 
on and off by controlling pin 3 of U106. Module U106 is not used 
during the transmit mode. During the transmit mode, transmit 5 volts 
(T5) for the ALC IC and...

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receive 5 volts (R5). During the receive mode, switch Q503 supplies 
regulated 5volts (R5) to the receiver front end. 
B+ Routing for 
VOCON Boards and 
Display ModulesRefer to Figure 3 and your specific schematic diagram.
Power for the radio is derived from a 7.5 volt battery, which is applied 
to the transceiver board through J3. This Raw B+, or unswitched B+ 
(UNSW B+), is routed to J1 on the transceiver board and then on to 
J401 on the VOCON board. Here the UNSW B+ is forwarded to the 
radio’s...

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Figure 3 .  B+ Routing for Vocoder/Controller (VOCON) Boards
5V Regulator
U410 ADSIC
U406 DSP56001
U405
256Kx8
FLASH
U404 8Kx24
SRAM
U402
Audio
PA
U401
SRAM
U202
EEPROM
U201
SLIC IV
U206Switch
Q207
On
Off
Controls
Flex
SW_B+
5V Analog
5V Digital
B+_CNTLB+_Sense
Vocoder/Controller
UNSW_B+ SW_B+
J401 J201 Universal ConnectorOpt_B+
Display Module
8Kx24
SRAM
U403
8Kx24
SRAM
U414
256Kx8
FLASH
U205
256Kx8
FLASH
U210
5V Regulator
U409
MAEPF-24335-O
HC11F1
MCU
U204