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VHF (7610) CIRCUIT DESCRIPTION
The phase detector determines the phase differ- ence between these signals and then produces output pulses on pin 8 which are filtered by the loop filter.
This filter consists of
5.3.2 VCO CIRCUIT
The VCO signal is amplified by buffer amplifiers Q6 and Q4 and is then applied to T/R switch D5 and D6. The VCO receive injection signal is applied to first mixer Q13 via bandpass filter L23, L24, and
5.4 VHF IC PIN DESCRIPTIONS
5.4.1 VHF POWER SUPPLY
Line | Description |
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|
VCC | Unswitched input voltage to the transceiver. |
|
|
HV | VCC supply voltage switched by Q25 and Q26. |
| When the [POWER] switch is pressed, the CPU |
| outputs the “PWON” control signal to this circuit |
| to turn the HV supply on. |
|
|
CPU5V | Common 5V supply for the CPU produced from |
| the VCC supply by CPU5V regulator IC9. The |
| circuit outputs this voltage regardless of the |
| transceiver |
|
|
8V | Common 8V supply produced from the HV |
| supply by 8V regulator Q36. |
|
|
5V | Common 5V supply produced from the VCC |
| supply by 5V regulator Q29/Q30. |
|
|
R5 | Receive 5V supply produced by R5 regulator |
| Q27 using the “T5C” signal from I/O expander |
| IC IC11. |
|
|
T5 | Transmit 5V supply controlled by T5 regulator |
| Q28 using the “T5C” signal from I/O expander |
| IC11. |
|
|
5.4.2 VHF CPU IC1 PORT ALLOCATION
Pin | Port | Description | |
No. | Name | ||
| |||
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|
| |
1 | VIN | Input port for overvoltage detection from | |
|
| the vehicle power source. | |
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| |
12 | SCK | Outputs clock signal to EEPROM IC3, | |
|
| PLL IC2 (main unit) and expanders IC5, | |
|
| IC11 (main unit), etc. | |
|
|
| |
13 | SI | Input port for the data signal from | |
|
| EEPROM IC3, etc. | |
|
|
| |
14 | SO | Outputs data signal to EEPROM IC3, PLL | |
|
| IC2 (main unit) and expanders IC5, IC11 | |
|
| (main unit). | |
|
|
| |
16 | CLIN | Input port for cloning signal. | |
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| |
17 | CLOUT | Output port for cloning signal. | |
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| |
18 | POSW | Input for the POWER switch. Low = | |
|
| POWER switch pushed. | |
|
|
| |
19 | NOIS | NOIS signal input port from the FM IF | |
|
| IC3 (main unit) for noise squelch | |
|
| operation. | |
|
|
| |
26 | PTT | Input port for the PTT switch. Low = PTT | |
|
| switch pushed. | |
|
|
| |
32 | RFATT | Outputs RF attenuator control signal to the | |
|
| attenuator switch (Q35 on main unit). | |
|
| Low = Attenuator function on. | |
|
|
| |
36 | UNLK | Input port for PLL unlock signal from the | |
|
| PLL IC2 (main unit). High = unlock. | |
|
|
| |
37 | PWON | Outputs control signal for the power | |
|
| switching circuit (Q25 on main unit) and | |
|
| 5V regulator Q29, Q30 (main unit). | |
|
|
| |
38 | DIM | Outputs control signal for LCD backlight. | |
|
| Low = LCD backlight on. | |
|
|
| |
39 | EXTPTT | Input port for the PTT switch from exter- | |
|
| nal connector J3 (main unit). Low = Exter- | |
|
| nal PTT switch on. | |
|
|
| |
40 | DIM | Input port for the LCD backlight control | |
|
| signal from external connector J3 (main | |
|
| unit). Low = External dimmer switch on. | |
|
|
| |
41 | PLST | Outputs strobe signals for PLL IC2 (main | |
|
| unit). | |
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| |
42 | DAST | Outputs strobe signals for level controller | |
|
| IC5 (main unit). | |
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| |
43 | EXST | Outputs strobe signals for the I/O | |
|
| expander IC11 (main unit). | |
|
|
| |
45, | KS1, | Output ports for the key matrix. | |
46 | KS2 |
| |
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| |
47- | KR3- | Input ports for the key matrix. | |
50 | KR10 |
| |
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| November 1998 |
Part No. |