Motorola Gm Series Detailed 6864115b62 A Manual

Notes For All Schematics and Circuit Boards2-5
5.0 Notes For All Schematics and Circuit Boards
* Component is frequency sensitive. Refer to the Electrical Parts List for value and usage.
1.Unless otherwise stated, resistances are in Ohms (k = 1000), and capacitances are in picofarads 
(pF) or microfarads (µF).
2.DC voltages are measured from point indicated to chassis ground using a Motorola DC 
multimeter or equivalent. Transmitter measurements should be made with a 1.2 µH choke in 
series with the...

2-6MAINTENANCE
CH ACT Channel Activity Indicator Signal (Fast Squelch)
CH KP ID Control Head Keypad ID (Data) Lines
CH REQUEST Control Head Request from Control Head *P
CLK Clock Signal
CNTLVLTG PA Power Control Voltage
CNTR AUDIO Audio Lines of the Controller
COL x Keypad Matrix Column x
CSX Chip Select Line PCIC / FRACN
DATA Data Signal
DC POWER ON Electronic Switching On or Off of the Radios Voltage Regulators
DISCAUDIO Audio Output Signal from the Receiver IC
ECLK Clock (not used)
EE CS EEPROM Chip...

Notes For All Schematics and Circuit Boards2-7
IN 5V RF REG Supply Voltage for 5V Regulator in RF Section
INT KP COL Internal Keypad Matrix Column Signal
INT KP ROW Internal Keypad Matrix Row Signal
INT MIC Internal (from Control Head) Microphone Input
INT SWB Internal Switched 13.2V Supply Voltage
INT SWB+ Internal Switched 13.2V Supply Voltage
IRQ Interrupt Request from Control Head
K9V1 9.1V in Transmit Mode
KEYPAD ID Keypad Identification Line
LCD A0 LCD Control / Display Data Select
LCD CS LCD Chip...

2-8MAINTENANCE
RAM CS RAM Ship Select
RDY Service Request Line from Option Board
REF CS Reference Chip Select (not used)
RESET Reset Line
ROW x Keypad Matrix Row x
RSSI Received Signal Strength Indicator
RX ADAPT Flat TX Path Disable during Transmitter Key-up
RX AUD RTN Option Board Input / Output of Receiver Audio Path
RX FLAT FILTERED AUDIO Flat or Filtered Audio to Accessory Connector
RXIN RF Signal from Antenna Switch into the Receiver
RXINJ RF Signal from the VCO into the Mixer
SCI RX Serial...

Notes For All Schematics and Circuit Boards2-9
VS MIC Voice Storage Audio Signal into Microphone Path
VS RAC Voice Storage Row Address Clock Signal
VSF Voltage Super Filtered (5V)
VSTBY 5V Supply for *P when the Radio is switched off
4-LAYER CIRCUIT BOARD DETAIL VIEWING
COPPER STEPS IN PROPER LAYER SEQUENCE
LAYER 1 (L1)
LAYER 2 (L2)
LAYER 3 (L3)
LAYER 4 (L4)
INNER LAYERS SIDE 1
SIDE 2 

2-10MAINTENANCE 

Chapter 3
SERVICE AIDS
1.0 Recommended Test Tools
Table 3-1 lists the service aids recommended for working on the radio. While all of these items are 
available from Motorola, most are standard workshop equipment items, and any equivalent item 
capable of the same performance may be substituted for the item listed.
Table 3-1   Service Aids
Motorola Part 
NumberDescription Application
RLN4460_Portable Test SetEnables connection to audio/accessory jack. 
Allows switching for radio testing.
RKN4081_...

3-2SERVICE AIDS
2.0 Test Equipment
Table 3-2 lists test equipment required to service the radio and other two-way radios.
Table 3-2   Recommended Test Equipment
Motorola Part 
NumberDescription Characteristics
Application
R2600_NTComms System Analyzer 
(non MPT)This monitor will 
substitute for items 
with an asterisk*Frequency/deviation 
meter and signal 
generator for 
widerange 
troubleshooting and 
alignment
R2680_NT Comms System Analyzer 
( MPT1327) to be ordered 
with 
RLN1022_ (H/W) 
RLN1023_...

 Professional Radio
GM Series
LB1 (29.6 - 36.0MHz)
LB2 (36.0 - 42.0MHz)
LB3 (42.0 - 50.0MHz)
Issue: March 2001 

ii
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reproduce in any form, the copyrighted computer program. Accordingly, any copyrighted Motorola computer 
programs contained in the Motorola products described...