User's Manual

TC-700 Circuit Description
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3） MSK
Transmit: MSK signal produced by base band processing IC enters VCO together with AF
signal for modulation.
Receive: MSK input of demodulating IC is sent to AK2346 for demodulation after being
amplified. The demodulated signal is then sent to MCU for decoding.
4） AF
Transmit: AF signal from MIC enters base band processed IC for amplification, pre-emphasis
etc. after being amplified. And then it enters VCO for modulation.
Receive: Demodulated AF signal enters the base band processing IC for amplification,
de-emphasis etc. after being amplified. And then it enters AF power amplifier drived
speaker.
Base band processed chip provides functions for processing signal as amplifying,
filtering, emphasizing, scrambling, companding, and amplitude limiting.
6．Control System
The IC500 CPU operates at 9.8304 MHz.
The block diagram of MCU control system is shown as following：
Fig.6 MCU Block Diagram
Circuit in this section is mainly comprised of MCU, EEPROM etc.
MCU control circuit accomplishes the following functions: accomplish the reset initialization according to
the programmed feature of the radio when power on; detect keying signal and monitor battery voltage;
send necessary frequency data to PLL according to encode of the channel; switch and control
transmit/receive according to the signal input from PTT; turn on/off the mute circuit according to the input
signaling decode signal and squelch level signal; output control signal to control the light/off of LED;
control signaling process IC to perform tasks.
EEPROM