User's Manual

When P0.4 is high, 25KHz(F13) is selected. When P0.4 is low, 12.5KHz(F14) sis selected.
455KHz Resonat or eliminate Carrier between received second IF Carrie and data signal and detect signal. In 25KHz,
Q14 turn on and reduce 455KHz Resonator to remain data signal stable volume of 12.5/25KHz.
Noise Squelch signal identically detect noise squelch signal in 12.5/25KHz. RSSI signal alters to voltage according to
signal strength inside of IF IC and provide D-SUB connector No. 8 pin.
3.5 Data Handling
Data handling part reverse or de-reverse signal at 2V with OP AMP (U12).
If users use TX data at 1/2 VCC voltage, user can use U12A No.1 pin (Invert Signal) or U12B No.7pin (Normal Signal).
After eliminating DC part, user can use as C48.
3.6 MPU (U13)
MPU operates after down loading RF status with D-SUB Connector No. 6 pin (S_I/O).
EEPROM (U14) stores Paramet er of every kind and provide information.
Each port for MPU as following table
Port 0 Port 0
P0.0 S_CLOCK P2.0 H/L_POW
P0.1 S-DATA/H/L_BAND P2.1 PLL_LOCK
P0.2 S_I/O P2.2 EEPORM DATA
P0.3 PTT P2.3
PLL_CLOCK/
EEPROM CLOCK
P0.4 12.5/25KHz P2.4 PLL_DATA
P0.5 RX_CON P2.5 PLL_ENABLE
P0.6 TX_VCO P2.6 TX_POW
P0.7 RX_VCO