Notes For All Schematics and Circuit Boards 2-5
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 voltage probe to prevent circuit loading.
3. Interconnect Tie Point Legend:
Signal Name Signal Description
16_8MHz 16.8MHz Reference Frequency from Synthesizer to ASFIC
3V 3V RF regulator
5V 5V RF regulator
5V_CH Optional 5V for Control Head
9V Regulated 9.3V Supply Voltage
9R 9V to enable RX_INJ when RX_EN is active
ASFIC_CS ASFIC Chip Select
B+ 13.8V Supply Voltage
BATT_SENSE Battery Voltage Sense Line
BOOT_EN_IN_CH Boot Mode Select
BW_SEL Select BW (12.5 kHz, 25 kHz)
CH_ACT Channel Activity Indicator Signal (Fast Squelch)
COMM_DATA_SEL_CH Display Driver Command/ Data Select
D3_V3 Regulated 3.3V supply voltage for Voice Storage
DEMOD Audio Output Signal from the Receiver IC
DETECTOR_AUDIO_SEND_BRD Flat Audio to Option Board
DISPLAY_CS_CH Control Head Chip Select
EMERGENCY_ACCES_CONN Emergency line to switch on the radio voltage regulators
EMERGENCY_SENSE Emergency sense to µP
EXTERNAL_MIC_AUDIO ACCES_CONN External (from accessory connector) microphone input
F1200 Interrupt line from ASFIC CMP
FILT_SW_B+ Switched 13.8 V supply voltage
FLAT_TX_AUDIO_INPUT_ACCESS_CONN Flat TX input from accessory connector
HANDSE RX_AUDIO_CH Handset Audio Output
HOOK_CH Hang-up switch input
HSIO High Speed Clock In / Data Out
IGNITION Ignition Line to switch on the radio’s voltage regulator
KEYPAD_COL_CH Keypad Matrix Column
LOC_DIST Enable Attenuator for RX line
LSIO Low Speed Clock In / Data Out
MIC_AUDIO_CH Microphone Input
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