Alinco Dj-195 Service Manual

DJ-195
Service Manual
CONTENTS
SPECIFICATIONS
1) GENERAL ................................................................ 2
2) TRANSMITTER ........................................................ 2
3) RECEIVER ............................................................... 2
CIRCUIT DESCRIPTION
1) Receiver System .................................................. 3, 4
2) Transmitter System ................................................... 4
3) PLL Synthesizer Circuit...

2
SPECIFICATIONS
1) GENERAL
Frequency coverage T : TX 144 ~ 147.995MHz RX 135 ~ 173.995MHz
E : TX 144 ~ 145.995MHz RX 144 ~ 145.995MHz
EAH : TX 135 ~ 173.995MHz RX 135 ~ 135.995MHz
TFH : TX 150 ~ 173.995MHz RX 135 ~ 173.995MHz
TLH : TX 150 ~ 173.995MHz RX 135 ~ 173.995MHz
Mode F3E (FM)
Channel steps 5,10,12.5,15,20,25, & 30kHz
Memory channels 40 channels+1 CALL channel
Antenna connector BNC (50Ω unbalanced)
Frequency stability ±5 ppm
Microphone input impedance 2kΩ nominal
Power supply requirement 6.0 ~...

3
CIRCUIT DESCRIPTION
1) Receiver System
The receiver system is a double superheterodyne system with a 21.7MHz first IF and a 450kHz second IF.
1. Front End
The received signal at any frequency in the 130.00- to 173.995-MHz range is
passed through thelow-pass filter (L2, L3, L11, C13, C14, C15 and C60) and
tuning circuit (L16 and D15), and amplified by the RF amplifier (Q11). The
signal from Q11 is then passed through the tuning circuit (L17, L18, L19 and
varicaps D13, D14 and D16) and conver ted into...

4
5. Squelch Circuit
The signal except for the noise component in AF signal of IC5 is cut by the
active filter inside IC. The noise component is amplified and rectified, then con-
ver ted to the DC voltage to output from pin13 of IC5. The voltage is led to pin 2
of CPU and compared with the setting voltage. The squelch will open if the
input voltage is lower than the setting voltage.
2) Transmitter System
1. Modulator Circuit
The audio signal is converted to an electric signal in either the internal or...

5
3. Phase Comparator Circuit
The PLL (IC1) uses the reference frequency, 5 or 6.25kHz. The phase com-
parator in the IC1 compares the phase of the frequency from the VCO with that
of the comparison frequency, 5 or 6.25kHz, which is obtained by the internal
divider in IC1.
4. PLL Loop Filter Circuit
If a phase difference is found in the phase comparison between the reference
frequency and VCO output frequency, the charge pump output (pin 8) of IC1
generates a pulse signal, which is conver ted to DC...

6
6. Tone Encoder
The CPU (IC9) is equipped with an internal tone encoder.The tone signal (67.0
to 250.3Hz) is output from pin 9 of the CPU to the varicap (D3) of the VCO for
modulation.
7. DCS Encoder
The CPU (IC9) is equipped with an internal DCS code encoder. The code (023
to 754) is output from pin 9 of the CPU to the varicap (D3) of the PLL reference
oscillator. When DCS is ON, DCS MUTE circuit (Q15-ON, Q18-ON, Q16-OFF)
works. The modulation activates in X1 side only.
8. CTCSS, DCS Decoder
The voice...

7
No. Pin Name       Function  I/O PU Logic Description
1 P67/AN7 SMT I - A/D S-meter input
2 P66/AN6 SQL I - A/D Noise level input for squelch
3 P65/AN5 BAT I - A/D Low battery detection input
4 P64/AN4 TIN I - A/D CTCSS tone input/DSC code input
5 P63/SCLK22/AN3 BP1 I - A/D Band plan 1
6 P62/SCLK21/AN2 BP2 I - A/D Band plan 2
7 P61/SOUT2/AN1 DCSW O - Activ high DCS signal mute
8 P60/SIN2/AN0 F/M/KEY I - A/D Function/Moniter key input
9 P57/ADT/DA2 CTOUT O - D/A CTCSS
 tone output/DCS tone output/Tuning...

8
No. Pin Name Function  I/O  PU Logic Description
56 P06/SEG32 AFC O - Activ high AF tone control
57 P05/SEG31 S31 O - -
58 P04/SEG30 S30 O - -
59 P03/SEG29 S29 O - -
60 P02/SEG28 S28 O - -
61 P01/SEG27 S27 O - -
62 P00/SEG26 S26 O - -
63 P37/SEG25 S25 O - -
64 P36/SEG24 S24 O - -
65 P35/SEG23 S23 O - -
66 P34/SEG22 S22 O - -
67 P33/SEG21 S21 O - -
68 P32/SEG20 S20 O - -
69 P31/SEG19 S19 O - -
70 P30/SEG18 S18 O - -
71 SEG17 S17 O - -
72 SEG16 S16 O - -
73 SEG15 S15 O - -
74 SEG14 S14 O - -
75 SEG13 S13...

9
SEMICONDUCTOR DATA
1) NMJ2070M T1  (XA210)
Low Voltage  Power  Amplifier
Equivalent Circuit
2) AT24C16N-10SI-2.7TER (XA0368)
16K bits CMOS Serial EEPROM