Notes For All Schematics and Circuit Boards 2-9
ON OFF SENSE (Controller) Service Request Line from Control Head
OPT CS Option Board Chip Select
OPT PTT PTT from Option Board
PA PWR SET ASFIC Output Voltage to set the Transmitter Power
PA SWB Switches Supply Voltage for PA Current Control Circuitry
PA SUPVLTG 13.2 V Supply Voltage of the Transmitter PA
PCIC MOSBIAS 1 PA Bias Voltage for first Stage
PRESC Prescaler Signal from VCO to Synthesizer
PTT IRDEC Microphone PTT Input
PTT IRDECODER Microphone PTT Input
R W Read Write Signal for RAM / Flash
RAM CS RAM Chip 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 Communication Interface Receive Line
SCI TX Serial Communication Interface Transmit Line
SPI Serial Peripheral Interface Bus
SPKR- Negative Audio PA Speaker Output
SPKR+ Positive Audio PA Speaker Output