AMC XT User manual

STEREOTUNER

TUNER ALIGNMENT PROCEDURE
FM SECTION
A. PREPARATION
1. Set stereo modulator to mono mode with 1KHz modulating signal unless otherwise state.
2. Set signal generator to FM mode with 75KHz deviation.
3. Store the following frequencies: 87.5MHz, 90.1MHz, 98.1MHz, 106.1MHz and 107.9MHz.
4. RF levels are open circuit voltages of signal generator with 75 ohms output impedance.
B. OSCILLATOR TUNING VOLTAGE
1. Connect DVM between FE1 No. 5 PIN and ground.
2. Tune to 87.5MHz and check DVM for reading of 3Vdc +/-0.5Vdc
3. Tune to 107.9MHz and check DVM for reading of 20.5Vdc +/-0.5Vdc.
If either of the above is out of tolerance, adjust FE1 (oscillator coil L101) until both readings are
within tolerance.
C. I.F.
1. Connect DVM between TP2 and TP3.
2. Apply 98.1MHz (60dBu) to FM antenna input and tune to 98.1MHz.
3. Adjust IFT1 (FM IF) for 0Vdc +/-50mV reading on DVM.
4. Adjust IFT2 (FM IF) until minimum THD is achieved at audio output.
5. Repeat (3) and (4) until no further improvement can be made.
D. FRONT-END I.F.
1. Apply 98.1MHz (12dBu) to antenna input and tune to 98.1MHz.
2. Carefully adjust FE1 IFT until minimum THD is achieved at audio output.
E. R.F.
1. Apply 98.1MHz (7dBu) to antenna input and tune to 98.1MHz.
2. Check if THD is better than 3%. If not, proceed to (3).
3. Adjust FRONT-END COILS (L102 - L104) by squeezing or stretching using a non-metallic
tool until THD is better than 3%.
4. Check THD at 90.1MHz and 106.1MHz with 8dBu input. If THD is more than 3% for both
frequencies, re-adjust until required THD is met.
F. AUTOSEARCH AND FM STEREO LEVEL
1. Turn VR2 fully clockwise.
2. Set stereo modulator to L=R mode and 98.1MHz (32dB) to antenna input.
3. Adjust VR2 clockwise until “S” light up in the LCD.

4. Check if auto-search operation is working properly at antenna input level of 28dB.
G. CENTER TUNER LED
1. Turn VR1 fully clockwise.
2. Set stereo modulator to MONO mode and 98.1MHz (26dB) to antenna input.
3. Adjust VR2 clockwise until “I” display in the LCD.
H. STEREO SEPARATION AND PILOT SUPPRESSION
1. Modulate L- only at 98.1MHz (68dBu) and adjust VR3 for minimum output on right channel.
2. Modulate R- only and adjust VR3 for minimum output on left channel.
3. Repeat (1) and (2) until readings are the same and within specification (>45dB).
4. Turn off modulating signal but leave pilot tone.
5. Adjust FL6 and FL7 for minimum output on left and right channels, respectively.
AM SECTION
A. PREPARATION
1. Set signal generator to AM mode with 1KHz at 30% modulation.
2. Connect 22pF ceramic capacitor between signal generator and AM antenna input terminal
input; the capacitor should be as close as possible to antenna input terminal.
3. Store the following frequencies: 600KHz, 1000KHz and 1400KHz.
B. OSCILLATOR TUNING VOLTAGE
1. Connect DVM between TP4 and TP5 (Ground).
2. Tune to 600KHz and adjust L4 (AM OSC) for 1.75Vdc +/-50mV reading on DVM.
C. I.F.
1. Apply 1000KHz (45dBu) to antenna input.
2. Tune to 1000KHz and adjust IFT3 (AM IFT) for maximum reading on audio output.
D. R.F.
1. Apply 600KHz (45dBu) to antenna input.
2. Tune to 600KHz and adjust L3 (AM ANT) for maximum reading on audio output.
3. Apply 1400KHz (45dBu) to antenna input.
4. Tune to 1400KHz and adjust C26 (VC TRIM) for maximum reading on audio output.
5. Repeat (1) to (4) until no further improvement can be made.

ITEM PART NUMBER LOCATION Q'TY
1 90-1742-2 MODULE, TUNER MAIN PCB XT 1
2 29R-1236-220 L5.6. INDUCTOR 22uH 10% SMD 1210 2
3 29R-1236-2R2 L1. INDUCTOR 2u2H 10% SMD 1210 1
4 29R-1236-680 L2. INDUCTOR 68uH 10% SMD 1210 1
5 30R-LC72131M IC4. IC FREQ SYNTHESIZER LC72131M MFP20 RoHS SANYO 1
6 30R-MMBD4148 D5.6.8.12.13.14 DIODE SWITCHING MMBD4148/914 DIODE 0.2A/75V SOT-23 6
7 30R-MMBT4401LT1 Q1.10.11.12.14.15.19.20.26. TR NPN MMBT4401LT1 ON 0.6A/40V SOT-23 9
8 30R-MMBT4403LT1 Q9.13.25 TR PNP MMBT4403LT1 ON 0.6A/40V SOT-23 3
9 30R-M4 D9.10.11 RECTIFIER DIODE M4 1A 400V SMA WILLAS 3
10 30R-AT32L-8AU IC9. IC ATMEGA32L-8AU 8-BIT AVR 8K FLASH TQFP 44A 1
11 30R-2SC1815GR Q2.3. TR NPN 2SC1815GR TAP TOSHIBA 2
12 30R-2SC829C Q4.5.6.7.8. TR NPN 2SC829C TO-92 TAP 5
13 30R-J112 Q16.17.18. TR JFET N-ch J112 35V 350mW XT TO-92 ON/FAIRCHILD 3
14 17R-2019 C26. VC TRIM 30PF TZ03R300FR 1
15 16R-1AN121J R97. RES MO 120R 5% 1W RSF1 MK 1
16 29R-R6V104B VR2.3. SEMI-FIX VR 100KB RH0615C15J 2
17 30R-4020 X1. CER-RESONATOR CSB456F11 1
18 30R-4017-1 X2. CRYSTAL QUARTZ 7.2MHz HC-49US 1
19 15R-3010*A FEI. FRONT END KST-F724HA-1 1
20 17R-2016-1 FL4. CERAMIC FILTER SFZ450B 1
21 17R-2017 FL5. EMI FILTER S-174-077 1
22 17R-2027 FL1.2. CERAMIC FILTER 10.7MHz RED MURATA SFELF10M7FA00-B0 3
23 29R-1224 IFT2. FM IFT TWS-384-0428(4400) 1
24 29R-1225 IFT3. AM IFT TWS-384-0425(5200) 1
25 29R-1226 IFT1. FM IFT TWS-384-0427(4300) 1
26 29R-1228 FL6.7. MPX FILTER S-174-084 10DFEE01 2
27 29R-1230 L3. AM RF TWS-384-426 (M-10BLN) TUNER SERIES SUMIDA 1
28 29R-1231 L4. AM OSC TWS-384-424 1
29 30R-1N60*A D1.2. DIODE 1N60 (RED) 2
30 30R-LA1266 IC1. IC LA1266 (AM/FM IF) 1
31 30R-LA3401 IC2. IC LA3401 (FM MPX) 1
32 30R-M51951B IC6. IC RESET M51951BSL MITSUBISHI 1
33 30R-SVC321SPA D3.4. DIODE SVC321SPA(A) 2
34 12R-2154-1 J7. JACK RCA 2P SEMI GOLD PLATED DTR-0202G-004-1 1
35 12R-2240 J1. ANT TERMINAL AJ-2019-040 US XT 1
36 17R-2.5EF228M C89.90 CAP EL 2200uF/25V 20% HTC5 13x21mm 2
37 17R-2023-1 FL4. BAND PASS FILTER LPF88A 1
38 30R-HIN232CP IC5. IC RS232 DRIVER/RECEIVER HIN232CP DIP16 RoHS XT 1
39 30R-LM7805A IC9. IC POSITIVE VOL.REG.LM7805(F)A NS/JRC/ST/IR/ON 1A/5V TO-220 1
40 30R-LM7812A IC10. IC POSITIVE VOL.REG.LM7812(F)A NS/JRC/ST/IR/ON 1A/12V TO-220 1
41 30R-LM7912A IC11. IC NEGATIVE VOL.REG.LM7912(F)A NS/JRC/ST/IR/ON 1A/-12V TO-220 1
42 30R-MPS6724 Q21. TRANSISTOR MPS6724 1
43 30R-RB154 BD1. DIODE BRIDGE RB154 1.5A/400V 1
44 31R-1383 SW2. SWITCH SLIDE SKV-22D21-G6-TA 2P2T L=6mm 1
45 31R-1383-1 SW1. SWITCH SLIDE SKV-24D02-G6-NA 2P4T L=6mm XT 1
46 35R-3046 RL1. RELAY DPST 12V UL/CSA/VDE VB-12MBU-5 TAKAMISAWA 1
47 90-1798 MODULE, TUNER DISPLAY XT 1
48 19R-1798 PCB FR4 D-S DISPLAY XT 1
49 30R-MMBD4148 D1.2.3.4.5. DIODE SWITCHING MMBD4148/914 MZC&M DIODE 0.2A/75V SOT-23 5
50 30R-SAA6588T U100. IC RDS PRE-PROCESSOR SAA6588T SO20 PHILIPS 1
51 30R-PT2222-001 U101. IC RC TRANSMITTER PT2222-001 SOP24 PRINCETON 1
52 29R-1242 L1. FERRITE BEAD 1.0A 0805 ACM201209A600 1
53 30R-2SD1781KR Q1. TR NPN 2SD1781KR SOT-23 1
54 30R-M4 D15. RECTIFIER DIODE M4 MZC-66 1A 400V SMA WILLAS 1
55 30R-MIR053 LED1. DIODE INFRARED EMITTING MIR053 XT 1
56 30R-4028-1 X1. CRYSTAL 4.332MHz HC-49US 1
57 30R-4029 X2. RESONATOR CSB455EB MURATA 1
58 30R-1156*B LCD1. LCD MODULE C1624MWLJ1 16x2 ECOMAG w85xh30xd13.2mm 1
59 30-PIC-26043TH2 IR1. RECEIVER IR T7a PIC-26043TH2 1
60 31R-1365 S41-52.55.56.33.60. TACT SW SKHHBV2710-EK 7mm 6
61 31R-1375 TIME/TEXT/PROGRAM/TYPE. SWITCH TACT 4.5x6.5mm L=17mm KA-170 RoHS TECX 4
62 12R-2239-1 J3.J4. JACK DC POWER 2.5mm DJ-0702B-025 JYE TAI 2
63 31R-1383 SW3. SWITCH SLIDE SKV-22D21-G6-TA 2P2T L=6mm 1
64 90-1801 MODULE, POWER SUPPLY XT 1
65 19R-1801 PCB FR4 D-S POWER SUPPLY RoHS XT 1
66 31R-1250 SWITCH PUSH NON-LOCK 1P RoHS XT/AV81HT 1
XT SERVICE PART LIST - EC, BLACK
PART DESCRIPTION

67 XT-B-COM COMMON PARTS XT 1
68 11R-8644*A PANEL REAR RoHS XT 1
69 11R-8633B-2 PANEL FRONT BLACK XT w430xh72xd23mm 1
70 11R-6425-1 CHASSIS FRONT RoHS XT 420x57.2x13.5mm 1
71 11R-6436 CHASSIS MAIN RoHS XT 1
72 13-1063 WINDOW DISPLAY XT 1
73 11R-1123-1 COVER TOP BLK RoHS AMC 1
74 12-1083 POWER LINK 1
75 12R-1120 SHAFT BUTTON 6
76 12R-2177 ANT FM 300 ohm T TYPE 1
77 12R-2178 ANT FM BALUN AJ-2010 A1 75 ohm<-> 300 ohm 1
78 12R-2116*B AC INLET 3P W/FUSE HOLDER SC-8F-21C 10A/250V SWEETA 1
79 12R-3110 KNOB PUSH BLK 6
80 12R-3152GN POWER SW BUTTON GREEN AMC 1
81 13R-8227B POWER KNOB BUSHION AMC 1
82 28R-1046-1B FOOT (R) H=17mm BLK AMC 2
83 28R-1046-2B FOOT (L) H=17mm BLK AMC 2
84 29R-2185*B-UN TRANSFORMER POWER XT 1
85 29R-3071 RF CORE FILTER 1
86 30R-1148 LED 3mm BLUE M034BLD GAN/SIC 430nM PD=100mW VF=3.5
V
1
87 31R-1376 SWITCH SLIDE 115/230V EV-12-2 DPDT UL/VDE 1
88 21R-2622-1*A MANUAL INSTRUCTION RS232 1
89 XT-B-EC EC VER PARTS 230V 1
90 14R-5030*A POWER CORD EC 3P 1.83M BLK EL211+EL701 H05VV-F 0.75/3C 1
91 CTR-5264 CARTON INNER RoHS AMC w494xd361xh143mm 1
92 CTR-5265 CARTON OUTER RoHS AMC w506xd373xh664mm 0.25
93 R32S1250500TUS FUSE UTE T500mA/250V RoHS T-LAG (UL/CSA/VDE) 5x20mm 2
94 R32S12502K0TUSP FUSE UTE T2A/250V RoHS T-LAG (UL/CSA/VDE/PSE) 5x20mm 1

PART NUMBER XT-B_EC XT-B_A1 XT-S_EC
11-1123S ------ ------ 1
11R-1123-1 1 1 ------
11R-8633B-2 1 1 ------
11R-8633S-2 ------ ------ 1
12-3122S ------ ------ 16
12R-3097S ------ ------ 1
12R-3110 16 16 ------
12R-3152GN 1 1 ------
14R-5030*A 1 ------ 1
14R-5107*B ------ 1 ------
15R-2090B 4 4 ------
15R-2090S ------ ------ 4
16R-1:2CA275J ------ 1 ------
21-3024 3 ------ 3
21R-2315 ------ 1 ------
21R-2331-A1 ------ 1 ------
21R-2331-EC 1 ------ 1
21R-2332-A1 ------ 0.5 ------
21R-2332-EC 0.5 ------ 0.5
21R-2440 1 ------ 1
21R-3015-1 ------ 1 ------
XT DIFFERENT VERSION PART LIST