Icom IC-F24 Service Manual

Also see for IC-F24: Instruction manual Instruction manual Servise manual

Contents

Icom IC-F24 Service Manual Manual pdf 11 page image

4 - 5LINEVCC+5VS5VR5VT5VDESCRIPTIONThe voltage from the connected battery pack.Common 5 V converted from the VCC line atthe +5 regulator circuit (IC9). The output voltageis supplied to the D/A converter (IC8), analogSW (IC10), etc.Common 5 V converted from the VCC line atthe S5 regulator circuit (Q23–Q25). The outputvoltage is supplied to the ripple filter (Q17), PLLIC (IC4), etc.Receive 5 V converted from the S5V line at theR5 regulator circuit (Q22). The output voltageis supplied to the tripler (Q19), FM IF IC (IC1),IF amplifier (Q4), VCO switch (Q15, Q16), 1stmixer (Q3), etc.Transmit 5 V converted from the S5V line at theT5 regulator circuit (Q21). The output voltage issupplied to the YGR (Q9), pre-drive (Q5), APCamplifier (IC2), etc.4-5 POWER SUPPLY CIRCUITVOLTAGE LINE4-4 OTHER CIRCUITSLED CONTROL CIRCUITSThe LED control circuit is composed of the CPU (IC13),LED driver (Q32) and LED (DS1).The CPU outputs “RLED” and “TLED” signals from the pins42 and 43. The signals are applied to the LED driver (Q32,pins 2 and 5). The driver outputs LED control signals to theLEDs (DS1).4-6 PORT ALLOCATION4-6-1 D/A CONVERTER IC (IC8)CONDITION COLORRECEIVING (2/5-TONE CODE) ORANGE (Lighting)LOW BATTERY(Nearly exhausted) RED (Blinks Slowly)LOW BATTERY(Almost exhausted) RED (Blinks Fast)CLONING ORANGE (Blinking)RECEIVING/SQUELCH OPEN GREEN (Lighting)TRANSMITTING RED (Lighting)PinnumberPortname Description11 BALOutputs the modulation balance levelcontrol signal. The signal is appliedto the reference frequency crystaloscillator (X2, pin 1).14 LVAOutputs the PLL lock voltage controlsignal. The output signal is applied tothe RX VCO (Q14, D16, D22) and TXVCO (Q13, D17, D21).15 REFOutputs the reference oscillatorcorrecting voltage. The voltage is appliedto the reference frequency crystaloscillator (X2, pin 1).22 T1Outputs the bandpass filter tuningsignal. The output signal is applied tothe bandpass filters (D3, D4, D7, D8).23 T2• Outputs the bandpass filter tuningsignal during receive. The outputsignal is applied to the bandpassfilters (D9, D10).• Outputs the TX power control signalduring transmit. The output signal isapplied to the APC amplifier (IC2,pin 1).