4-3-2 VCO CIRCUIT (MAIN UNIT)
The VCO circuit contains a separate RX VCO (Q14, D19, D20) and TX VCO (Q13, D16, D17). The oscillated signal is amplified at the buffer amplifiers (Q10, Q12) and is then applied to the T/R switch (D14, D15). Then the receive 1st LO (Rx) signal is applied to the 1st mixer (Q3) and the trans- mit (Tx) signal to the
A portion of the signal from the buffer amplifier (Q12) is fed back to the PLL IC (IC4, pin 8) via the buffer amplifier (Q11) as the comparison signal.
4-4 POWER SUPPLY CIRCUIT
4-4-1 MAIN UNIT VOLTAGE LINE
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VCC | The voltage from the connected battery pack. | |
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| Common 5 V converted from the VCC line at the | |
+5V | +5 regulator circuit (IC9). The output voltage is | |
supplied to the fast switch (IC17), buffer ampli- | ||
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| fiers (IC16, IC18) and so on. | |
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| Common 5 V converted from the VCC line at the | |
S5V | S5 regulator circuit | |
age is supplied to the ripple filter (Q17), PLL IC | ||
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| (IC4), FRONT unit, etc. | |
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| Receive 5 V converted from the S5V line at the | |
| R5 regulator circuit (Q22). The output voltage is | |
R5V | supplied to the tripler (Q19), FM IF IC (IC1), IF | |
| amplifier (Q4), VCO switch (Q15, Q16), 1st | |
| mixer (Q3), etc. | |
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| Transmit 5 V converted from the S5V line at the | |
T5V | T5 regulator circuit (Q21). The output voltage is | |
| supplied to the | |
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•PLL CIRCUIT
4-4-2 FRONT UNIT VOLTAGE LINE
LINE | DESCRIPTION | |
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| Same voltage as VCC line on the MAIN unit is | |
VCC | applied to the FRONT unit via the J401, pins 1, | |
2 (FRONT unit). The voltage is supplied to the | ||
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| [PWR] switch controller (Q401, Q402). | |
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| Same voltage as +5V line on the MAIN unit is | |
CPU5 | applied to the FRONT unit via the J401, pin 4 | |
(FRONT unit). The voltage is supplied to the | ||
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| CPU (IC401), reset IC (IC408), etc. | |
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| Same voltage as S5V line on the MAIN unit is | |
S5V | applied to the FRONT unit via the J401, pin 5 | |
(FRONT unit). The voltage is supplied to the mic | ||
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| mute circuit (IC406), etc. | |
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| RX VCO |
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| D15 |
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| Buffer | |
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| Q10 |
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Buffer |
| Q14, D19, D20 |
| Buffer |
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| D14 | ||
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| Q8 |
| TX VCO |
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| Q12 |
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"LVIN" signal to the CPU |
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| Buffer |
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(FRONT unit; IC401, pin 49) |
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| Q11 |
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| Q13, D16, D17 |
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| Loop |
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| IC4 MB15A02 | LPF | ||
| filter |
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| 5 | Phase | Programmable | Prescaler | 8 |
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| detector | counter |
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45.9 MHz 2nd LO |
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| Programmable |
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| 9 | SCK | |
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| Shift register | 10 | |||||
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signal to the FM IF IC | Tripler |
| divider |
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| 11 | |||
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| PLST | ||||
(IC1, pin 2) |
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3 | 2 |
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| Q19 |
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| X2 |
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| 15.3 MHz |
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to 1st mixer circuit
to transmitter circuit
4 - 4