IC-208H_serv.pdf

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1、VHF/UHF FM TRANSCEIVER i208H SERVICE MANUAL INTRODUCTION This service manual describes the latest service information for the IC-208H VHF/UHF FM TRANSCEIVER at the time at the time of publication. DANGER NEVER connect the transceiver to an AC outlet or to a DC power supply that uses more than 16 V.

2、This will ruin the transceiver. DO NOT expose the transceiver to rain, snow or any liquids. DO NOT reverse the polarities of the power supply when con- necting the transceiver. DO NOT apply an RF signal of more than 20 dBm (100 mW) to the antenna connector. This could damage the transceiv- ers front

3、 end. ORDERING PARTS Be sure to include the following four points when ordering replacement parts: 1. 10-digit order numbers 2. Component part number and name 3. Equipment model name and unit name 4. Quantity required 1140005990 S.ICMB15A02PFV-1IC-208H MAIN UNIT5 pieces 8810009610 Screw FH M2.66 ZKI

4、C-208H Bottom cover 10 pieces Addresses are provided on the inside back cover for your convenience. REPAIR NOTES 1. Make sure a problem is internal before disassembling the transceiver. 2. DO NOT open the transceiver until the transceiver is disconnected from its power source. 3. DO NOT force any of

5、 the variable components.Turn them slowly and smoothly. 4. DO NOT short any circuits or electronic parts. An insu- lated tuning tool MUST be used for all adjustments. 5. DO NOT keep power ON for a long time when the trans- ceiver is defective. 6. DO NOT transmit power into a signal generator or a sw

6、eep generator. 7. ALWAYS connect a 50 dB to 60 dB attenuator between the transceiver and a deviation meter or spectrum ana- lyzer when using such test equipment. 8. READ the instructions of test equipment thoroughly before connecting equipment to the transceiver. To upgrade quality, any electrical o

7、r mechanical parts and internal circuits are subject to change without notice or obligation. MODEL IC-208H VERSION Taiwan U.S.A. Korea Australia Export SYMBOL TPE USA KOR AUS EXP TABLE OF CONTENTS SECTION 1SPECIFICATIONS SECTION 2INSIDE VIEWS SECTION 3DISASSEMBLY INSTRUCTIONS SECTION 4CIRCUIT DESCRI

8、PTION 4 - 1RECEIVER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 1 4 - 2TRANSMITTER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 4 4

9、 - 3PLL CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 6 4 - 4OTHER CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

10、 - 8 4 - 5POWER SUPPLY CIRCUITS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 8 4 - 6PORT ALLOCATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 - 9 SECTIO

11、N 5ADJUSTMENT PROCEDURES 5 - 1PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 - 1 5 - 2SOFTWARE ADJUSTMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

12、 . . . . . . .5 - 3 SECTION 6PARTS LIST SECTION 7MECHANICAL PARTS AND DISASSEMBLY SECTION 8SEMI-CONDUCTOR INFORMATION SECTION 9BOARD LAYOUTS 9 - 1CONTROL UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 - 1 9 - 2M

13、AIN UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9 - 3 9 - 3VCO BOARD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

14、9 - 5 SECTION 10BLOCK DIAGRAM SECTION 11VOLTAGE DIAGRAMS 11 - 1 CONTROL UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 - 1 11 - 2 MAIN UNIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

15、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 - 2 1 - 1 SECTION 1SPECIFICATIONS All stated specifications are subject to change without notice or obligation. MGENERAL Frequency range: *1Guaranteed 144.000 146.000 MHz only, *2Guaranteed 144.000 148.000 MHz only, *3Guaranteed 430.0

16、00 440.000 MHz only; *4Guaranteed 440.000 450.000 MHz only *5Guaranteed 430.000 434.000 MHz, 435.000 438.000 MHz only; *6Not guaranteed range Mode: FM, AM (AM range is 118.0 135.995 MHz and Rx only for USA and EXP.) Number of memory channel: 502 (including 2 call channels) Usable temperature range:

17、10C to +60C; +14F to +140F Frequency resolution: 5, 10, 12.5, 15, 20, 25, 30, 50, 100 and 200 kHz Scan mode: Full, Program, Priority, Memory channel, Bank, Skip and Tone Frequency stability: 10 ppm (10C to +60C; +14F to +140F) Power supply requirement: 13.8 V DC 15 % (negative ground) Current drain

18、(at 13.8 V DC): * 1VHF only (except KOR), *2TPE only Antenna connector: SO-239 (50 ) DATA connector: Mini DIN 6 pin Dimensions : 141(W)40(H)185.4(D) mm; 5916(W)1916(H)7932(D) inch (projections not included) Weight: 1.2 kg; 2 lb 10 oz MTRANSMITTER Output power: VHF55 W (50 W: KOR, 25W: TPE)/15 W/5 W

19、(selectable) UHF50 W/15 W/5 W (selectable) Modulation system: Variable reactance frequency Maximum frequency deviation: 5.0 kHz Spurious emissions: Less than 60 dB Microphone connector: 8-pin modular jack (600 ) MRECEIVER Receive system: Double-conversion superheterodyne Intermediate frequency: 1st

20、IF46.05 MHz 2nd IF450 kHz Sensitivity: Less than 0.18 V (at 12 dB SINAD) Squelch sensitivity: Less than 0.13 V (at threshold) Selectivity: More than 12 kHz/6 dB (Wide);More than 6 kHz/6 dB (Narrow) Less than 30 kHz/60 dB (Wide);Less than 20 kHz/60 dB (Narrow) Spurious and image rejection : More than

21、 60 dB Audio output power (at 13.8 V): More than 2.0 W at 10% distortion with an 8 load External speaker connector: 2-conductor 3.5(d) mm (18)/8 VERSION KOR USA AUS TPE EXP RX (MHz) 144.000146.000, 430.000440.000 118.000173.995* 2, 230.000549.995*4 810.000824.000* 5, 849.000869.000*5 894.000999.990*

22、 5 118173.995* 2, 230.000549.995*3, 810.000999.990* 6 144.000146.000, 430.000432.000 118173.995* 2, 230.000549.995*3, 810.000999.990* 6 TX (MHz) 144.000146.000* 2, 430.000440.000 144.000148.000, 420.000450.000* 4 144.000148.000, 420.000450.000* 3 144.000146.000, 430.000432.000 136.000173.995* 2, 400

23、.000478.995*3 VHFUHF High: 55 W* 1/50 W/25 W*2 12 A* 1/11.5 A/8 A*2 11.5 A/8 A TXMiddle: 15 W (Approx.)7.5 A Low: 5 W (Approx)5.5 A5.0 A RX Standby0.8 A Maximum output power1.0 A SECTION 2INSIDE VIEWS 2 - 1 CONTROL UNIT (TOP VIEW) LCD back lightLCD back light (DS22: CV1074) Key back light (DS22: CV1

24、074) Key back light DS13-DS18,DS20: SML512MW DS13-DS18,DS20: SML512MW DS21: SML-020MYT DS21: SML-020MYT LCD back light (DS22: CV1074) Key back lights DS13-DS18, DS20: SML512MW DS21: SML-020MYT MAIN UNIT (TOP VIEW) VCO board EE PROM VCO board EE PROM (IC501: HN58X24128FPI) AF amplifier (IC501: HN58X2

25、4128FPI) AF amplifier (IC510: LA4425A) 1st mixcer VHF band (IC510: LA4425A) 1st mixcer VHF band (Q32: 3SK299) 1st mixcer 400M,800MHz band (Q32: 3SK299) 1st mixcer 400M,800MHz band (IC12: PC2757TB) D/A converter (IC12: PC2757TB) D/A converter (IC11: M62352GP) Ceramic band pass filter (IC11: M62352GP)

26、 Ceramic band pass filter FI1: CFWS450HT FI1: CFWS450HT FI2: CFWM450E FI2: CFWM450E MAIN CPUMAIN CPU IC505 IC505 : HD6432143SA70FAUSA : HD6432143SA70FAUSA : HD6432143SA69FA exceptUSA : HD6432143SA69FA exceptUSA VCO board EEP ROM (IC501: HN58X24128FPI) AF amplifier (IC510: LA4425A) 1st mixer VHF band

27、 (Q32: 3SK299) 1st mixer 400M,800MHz band (IC12: PC2757TB) D/A converter (IC11: M62352GP) Ceramic bandpass filter FI1: CFWS450HT FI2: CFWM450E MAIN CPU IC505 : HD6432143SA70FAUSAonly : HD6432143SA69FA exceptUSA CONTROL UNIT (BOTTOM VIEW) Color controllerColor controller (Q6,Q7: 2SC4116) Control unit

28、 CPU (Q6,Q7: 2SC4116) Control unit CPU (IC6: HD6433842RB36H) Reset IC (IC6: HD6433842RB36H) Reset IC (IC2: S-80945CLMC-G7F) +5V regurator (IC2: S-80945CLMC-G7F) +5V regurator IC5: TA78L05F IC5: TA78L05F D4: MA8062 D4: MA8062 +8V regurator+8V regurator Q1: 2SC4116 Q1: 2SC4116 Q3: 2SA1734 Q3: 2SA1734

29、D5: MA8068 D5: MA8068 Color controller (Q6, Q7: 2SC4116) Control unit CPU (IC6: HD6433842RB36H) Reset IC (IC2: S-80945CLMC-G7F) +5V regulator IC5: TA78L05F D4: MA8062 +8V regulator Q1: 2SC4116 Q3: 2SA1734 D5: MA8068 MAIN UNIT (BOTTOM VIEW) +8V regurator+8V regurator (IC504: TA7808F) +5V regurator (I

30、C504: TA7808F) +5V regurator (IC503: TA7805F) D/A converter (IC503: TA7805F) D/A converter (IC4: M62363FP-650C) IF IC (IC4: M62363FP-650C) IF IC (IC8: TA31136FN) APC controller (IC8: TA31136FN) APC controller (IC15: NJM3404AV) 1st mixer UHF band (IC15: NJM3404AV) 1st mixer UHF band (Q35: 3SK299) PA

31、module UHF band (Q35: 3SK299) PA module UHF band (IC14: S-AU82L) PA module VHF band (IC14: S-AU82L) PA module VHF band (IC13: S-AV32)(IC13: S-AV32) +8V regulator (IC504: TA7808F) +5V regulator (IC503: TA7805F) D/A converter (IC4: M62363FP-650C) FM IF IC (IC8: TA31136FN) APC controller (IC15: NJM3404

32、AV) 1st mixer UHF band (Q35: 3SK299) PA module UHF band (IC14: S-AU82L) PA module VHF band (IC13: S-AV32) 2 - 2 SECTION 3DISASSEMBLY INSTRUCTIONS Removing the MAIN unit Unscrew 4 screws A, and remove the cover. Disconnect the cable B from J505, and remove the speaker. Remove 2 sheets c. Unscrew 8 sc

33、rews G, and remove the MAIN unit. J505J505J505 B C A A Unsolder 3 points D. Disconnect the cable E from J1. Unscrew 3 screws F, and remove the cover. J1J1J1 F D E G MAIN UNIT 3 - 1 Removing the CONTROL unit Remove 2 knobs A. Unscrew 2 screws C, and remove the LCD plate. Remove the CONTROL unit. A Un

34、screw 2 screws B, and remove the cover. B C CONTROL UNIT 3 - 2 4 - 1 4-1 RECEIVER CIRCUITS 4-1-1 DUPLEXER CIRCUIT (MAIN UNIT) The transceiver has a duplexer (low-pass and high-pass fil- ters) on the first stage from the antenna connector to sepa- rate the signals into VHF, UHF and above 800 MHz sign

35、als. The 2 of low-pass filters (L51, L52, L56, C295, C299 and L45, L46, L49, C282, C285, C289) are for VHF signals, the low-pass (L51, L52, L56, C295, C299) and high-pass (L47, L50, C284, C288, C292, C586) filters are for UHF signals and high-pass filter (L55, L58, C298, C302, C304) is for above 800

36、 MHz signals. The separated signals are applied to each antenna switch- ing circuits (except SHF signals). 4-1-2 ANTENNA SWITCHING CIRCUITS (MAIN UNIT) The antenna switching circuit functions as a low-pass filter while receiving. However, its impedance becomes very high while transmitting by turning

37、 ON diode (VHF: D47, D49, D50; UHF: D46, D48, D51). Thus transmit signals are blocked from entering the receiver circuits. The antenna switching circuit employs a 1/4 type diode switching sys- tem. SHF signals pass through the RX switching circuit (D44). The passed signals are then applied to the ea

38、ch attenuator circuits. 4-1-3 ATTENUATOR CIRCUITS (MAIN UNIT) The attenuator circuit attenuates the signal strength to a maximum of 10 dB to protect the RF amplifier from distortion when excessively strong signals are received. The signals from the antenna switching circuit pass through the each att

39、enuator circuit (for VHF is D49 and D50, for UHF is D46 and D48, for SHF is D39). The D/A converter outputs “ATT” signal (IC11, pin 6), and is then applied to the attenuator controller circuit (Q44). The circuit output attenuator control signals to each attenuator circuits. The attenuated signals ar

40、e applied to the each RF circuits. 4-1-4 RF CIRCUITS (MAIN UNIT) The RF circuit amplifies signals within the range of frequen- cy coverage and filters out-of-band signals. VHF RF CIRCUIT (118 MHz174 MHz) The signals from the attenuator circuit pass through the tun- able bandpass filter (D41, L40, L4

41、4, C273, C280). The fil- tered signals are amplified at the VHF RF amplifier (Q38) and are then enter another 3-stage tunable bandpass filter (D22, D23, D29, L28, C171, C174, C176, C177, C181, C185, C191, C198, C204, C208) to suppress unwanted sig- nals and improve the selectivity. The filtered sign

42、als are applied to the VHF 1st mixer circuit (Q32). UHF RF CIRCUIT (430 MHz440 MHz) The signals from the attenuator circuit are applied to the UHF RX switching circuit (D42). The signals are amplified at the UHF RF amplifier (Q39) and are then enter bandpass fil- ter (FI4) to suppress unwanted signa

43、ls. The filtered signals are applied to the UHF 1st mixer circuit (Q35). SECTION 4CIRCUIT DESCRIPTION LPF VHF signals (118 174 MHz) to the 2nd IF circuit 1st mixer (Q32) Q38 Q39 Q36 Q37Q41 Q40 1st mixer (Q35) 1st mixer (IC12) Antenna UHF signals (430 440 MHz) LPF T/R SW BPF RF AMP BPFATT RX SW 800M

44、signals (810 1000 MHz) HPF RX SW BPF RF AMP BPFATT RX SW RF AMP HPF T/R SW RF AMP BPF BPF ATT RX SW RX SW 400M signals (230 550 MHz) BPF RF AMP RX SW RX SW RX SW RF AMP RF CIRCUITS 4 - 2 ABOVE 230 MHz RF CIRCUIT (230 MHz550 MHz, EXCEPT 430 MHZ440 MHz) The signals from the attenuator circuit pass thr

45、ough the tun- able bandpass filter (D36, L37, L38, C242, C253, C261). The filtered signals are amplified at the above 230MHz RF amplifier (Q40) and are then enter another 2-stage tunable bandpass filter (D25, D30, C205, C212) to suppress unwanted signals and improve the selectivity. The filtered sig

46、nals are applied to the RF amplifier (Q36). The amplified signals pass through the 400 MHz RX switching circuit (D17), and then applied to the 400 MHz 1st mixer circuit (IC12). ABOVE 800 MHz RF CIRCUIT (810 MHz1000 MHz) The signals from the attenuator circuit pass through the tun- able bandpass filt

47、er (D37, L39, C243, C254, C260, C269). The filtered signals are amplified at the above 800 MHz RF amplifier (Q41) and are then enter another tunable band- pass filter (D26, D31, L27, L31, C188, C197, C206, C213, C223) to suppress unwanted signals and improve the selec- tivity. The filtered signals a

48、re applied to the RF amplifier (Q37). The amplified signals pass through the 400 MHz RX switching circuit (D18), and then applied to the 1st mixer cir- cuit (IC12) same as 400 MHz RF circuit. The tunable bandpass filters (D11D13, D15) employ var- actor diodes to tune the center frequency of the RF p

49、ass- band for wide bandwidth receiving and good image response rejection. 4-1-5 VHF 1ST MIXER CIRCUIT (MAIN UNIT) The 1st mixer circuit converts the received signal to a fixed frequency of the 1st IF signal with a 1st LO frequency. VHF 1ST MIXER CIRCUIT The signals from the VHF RF circuit are mixed with the 1st LO signal at the 1st mixer circuit (Q32) to produce a 46.05 MHz 1st IF signal. The 1st IF signal passes through the RX switching circuit (D8), and are then applied to the 1st IF cir- cuit. UHF (430 MHz440 MHz) 1ST MIXER CIRCUI