TH-K4AT/K4E DISASSEMBLY FOR REPAIR How to remove the case assembly from the chassis 1. Remove two screws ( ) holding the chassis. 2. Pull out two knobs ( ) and remove two round nuts ( 3. Pull out the SP and MIC parts of the cap from jacks ( 4.
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TH-K4AT/K4E DISASSEMBLY FOR REPAIR Soldering the antenna terminal 4. Apply the tips of soldering irons to all the four pins of the final FET at the same time ( ), heat them sufficiently, and remove 1. With the shield cover removed from the antenna terminal the final FET ( ).
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TH-K4AT/K4E DISASSEMBLY FOR REPAIR Special care and attention required for assembly (2) By pressing the LCD hardware fixture from the component side of the TX-RX PCB, you must bent all 4 tabs of the LCD 1. Gluing to the key top (MIC element section)
TH-K4AT/K4E DISASSEMBLY FOR REPAIR 4. Packing (G53-1572-02) TX/BUSY lamp installation 6. Cautions for installing the chassis on the case assembly procedure (1) Verify that the packing (G53-1572-02) TX/BUSY lamp section (1) To assure waterproofing, install the packing in the chassis is has been past through the hole in the illumination guide groove as shown in Fig.
TH-K4AT/K4E CIRCUIT DESCRIPTION Frequency Configuration First Mixer The received signal passing through the band-pass filter The frequency configuration is shown in Figure 1 and (L32, L34) is mixed with the first local signal generated by the Table 1. 450kHz VCO by the first mixer (Q16) to produce a first IF signal (38.85 TX/RX : 400.000~469.995MHz(M2)
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TH-K4AT/K4E CIRCUIT DESCRIPTION IF Circuit FM IC and band-pass filter consisting of R125, R126, R135, The first IF signal (38.85 MHz) amplified by the IF amplifier (Q24) C173, C174. The noise component is rectified in the FM IC to and the second IF signal (38.4 MHz) generated by tripling the 12.8...
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TH-K4AT/K4E CIRCUIT DESCRIPTION Transmitter System The transmission/reception switching circuit consists of D10, D11, L19, D12 and D13. These diodes are turned ON in Microphone Amplifier Circuit transmit mode and OFF in receive mode to switch signals. The audio signal from the microphone passes through a high-pass filter (IC5) and enters a microphone amplifier (IC16).
TH-K4AT/K4E CIRCUIT DESCRIPTION The APC voltage controls the gate voltage of Q11 and Q12, amplifying VCO output with an RF amplifier (Q6) and dividing and keeps transmission output stable. it with the PLL IC. The MPU detects power supply voltage and controls Q58 The PLL synthesizer with 5 kHz and 6.25 kHz step is...
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TH-K4AT/K4E CIRCUIT DESCRIPTION Power Supply Circuit Power Supply Switching Circuit The voltage supplied through the battery terminal or DC IN Charging Circuit terminal is branched in the power supply switching circuit as When an external power supply is connected to the DC IN shown in Fig.10 and then supplied to the required components.
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TH-K4AT/K4E CIRCUIT DESCRIPTION Voltage Detection Circuit LED Drive Circuit Various voltages are input to the A/D port of the MPU (IC8) The LCD and key illumination LEDs are lighted by controlling for processing. Q51 for the LCD and Q50 for keys according to the output Battery voltage is divided with resistors (R240, R241) and voltage from the AF/LAMP AVR (Q37).
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TH-K4AT/K4E CIRCUIT DESCRIPTION Key and Encoder Input Circuit The POWER key is assigned to the interrupt port (pin 95) of Other keys composes a matrix and key presses are detected the MPU. by scanning them by software. The PTT key is assigned to the dedicated port (pins 13, 14) The encoder reads data using the interrupt port (pins 35 of the MPU.
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TH-K4AT/K4E CIRCUIT DESCRIPTION CTCSS/DCS DTMF The encode signal is generated by the MPU (IC8) and output The DTMF signal is generated by the MPU (IC8) and is from the TONE terminal (pin 41) of the MPU. output from the DTMF/BEEP terminal (pin 40) of the MPU.
TH-K4AT/K4E SEMICONDUCTOR DATA MPU : 90522BPFFG139 (IC8) Pin function Function Function Name Name CLOCK Common serial clock output Noise voltage input for squelch (A/D) DATA Common serial data output RSSI voltage input for S-meter (A/D) EEPDI Data input from EEPROM...
TH-K4AT/K4E SEMICONDUCTOR DATA / COMPONENTS DESCRIPTION COMPONENTS DESCRIPTION Function Name TX-RX UNIT (X57-675X-XX) DC IN detection interrupt input ( ↓ ) DCDET L:DC IN connected Ref. No. Use/Function Operation/Condition/Compatibility RXLED Busy LED output H:ON PLL IC 100 BSFT Beat shift swiching output...
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TH-K4AT/K4E COMPONENTS DESCRIPTION Ref. No. Use/Function Operation/Condition/Compatibility Ref. No. Use/Function Operation/Condition/Compatibility Q33 operation On when charging switch constant-voltage DC IN detection H: DC IN detection Reverse current Battery Ni-MH temperature prevention On when temperature detection is activated detection Reverse current...
LED(YG) D48,49 B30-2237-05 LED(YG) ∗ B62-1757-00 INSTRUCTION MANUAL(FRENCH) ∗ B62-1758-00 INSTRUCTION MANUAL(DUTCH) CK73HB1C103K CHIP C 0.010UF K B72-2131-04 MODEL NAME PLATE(TH-K4AT) ∗ ∗ CC73HCH1H390G CHIP C 39PF ∗ B72-2132-04 MODEL NAME PLATE(TH-K4E) CC73HCH1H020B CHIP C 2.0PF CK73HB1H471K CHIP C 470PF 2B,2D ∗...
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CHIP C 470PF C152,153 CK73HB1H471K CHIP C 470PF C242 CK73HB1C103K CHIP C 0.010UF K C156 CK73HB1H471K CHIP C 470PF C243 CK73HB1H471K CHIP C 470PF C157 ∗ CC73HCH1H180G CHIP C 18PF C246 C92-1327-05 CHIP-TAN 100UF 10WV E : TH-K4E M2 : TH-K4AT...
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SMALL FIXED INDUCTOR(4.7UH) C372 CK73GB1H471K CHIP C 470PF C374 CC73HCH1H101J CHIP C 100PF L40-2775-71 SMALL FIXED INDUCTOR(27NH) C510 CK73HB1A473K CHIP C 0.047UF K L92-0161-05 BEADS CORE C511 CK73HB1H471K CHIP C 470PF L92-0163-05 BEADS CORE E : TH-K4E M2 : TH-K4AT...
TH-K4AT/K4E EXPLODED VIEW (TH-K4AT) TX-RX Unit (B/3) TX-RX Unit (C/3) TX-RX Unit (A/3) 701. STICKER A : N09-1492-05 B : N14-0569-04 C : N14-0573-04 D : N79-2035-46 E : N79-2040-45 F : N82-2007-46 G : N09-2433-05 Parts with the exploded numbers larger than 700 are not supplied.
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TH-K4AT/K4E EXPLODED VIEW (TH-K4E) TX-RX Unit (B/3) TX-RX Unit (C/3) TX-RX Unit (A/3) 701. STICKER A : N09-1492-05 B : N14-0569-04 C : N14-0573-04 D : N79-2035-46 E : N79-2040-45 F : N82-2007-46 G : N09-2433-05 Parts with the exploded numbers larger than 700 are not supplied.
TH-K4AT/K4E ADJUSTMENT Single Tone Mode G. 7.5V TX M power (Lower limit frequency, center frequency, upper limit frequency) This mode is used to check the DTMF deviation. H. 7.5V TX L power (Lower limit frequency, center frequency, upper limit frequency) Operation I.
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TH-K4AT/K4E ADJUSTMENT Key name [key] [F] key → [key] Transmit while this key is held down. Selecting a TX power (High/Mid/Low) Changes adjustment items. (Forward) LAMP Lamp always ON When this key is pressed on the frequency display, it switches to the adjustment display.
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TH-K4AT/K4E ADJUSTMENT D. S-meter (Two segments in S-meter light, all segments 2RX BPF (Center frequency) in S-meter light) (1) Press the [LAMP] or [MONI] key on the transceiver to display 1S-meter (Two segments in S-meter light) “BPC” on the LCD.
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TH-K4AT/K4E ADJUSTMENT (8) Press the [MENU] key to write the current APC value into (5) Press the [PTT] key to enable the transmit mode. the EEPROM. (6) Adjust the output voltage from DC power supply until the voltage at the battery terminal becomes 7.5V while the 27.5V TX H power (Center frequency)
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TH-K4AT/K4E ADJUSTMENT (2) Press the [VFO], [MR] or [CALL] key to switch to the The current APC value is displayed at the lower digits of frequency display. the frequency display, and the value stored in the EEPROM (3) Turn the encoder to display the lower limit frequency on is displayed on the memory channel number display.
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TH-K4AT/K4E ADJUSTMENT J. 13.8V TX M power (Lower limit frequency, center (4) Repeat steps (4) to (7) of “113.8V TX M power (Lower frequency, upper limit frequency) limit frequency)” described on page 32. 113.8V TX M power (Lower limit frequency) (1) Press the [LAMP] or [MONI] key on the transceiver to display K.
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TH-K4AT/K4E ADJUSTMENT 2Tone deviation (Center frequency) (2) Press the [VFO], [MR] or [CALL] key to switch to the frequency display. (1) Press the [LAMP] or [MONI] key on the transceiver to display (3) Turn the encoder to display the upper limit frequency on “DVC”...
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TH-K4AT/K4E ADJUSTMENT (4) Press the [CALL] key to switch to the adjustment display. (2) Input a specified AG signal to microphone input. (5) When the [PTT] key is pressed to enable transmit mode, a (3) Press the [MENU] key to write the current microphone input preset DCS code (023) is internally generated and level value into the EEPROM.
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TH-K4AT/K4E ADJUSTMENT Common Section Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method 1.Setting and Connect the optional PG-2W LCD total illumination display Initial configuration displayed after resetting DC cable to the power supply. the full-reset.
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TH-K4AT/K4E ADJUSTMENT Receiver section Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method 1.RX BPF Squelch level: 0 Adjust 1) Frequency: 435.050MHz TX-RX Turn the VOL knob 0.63V SSG output: –53dBm (501 uV) Oscilloscope (A/3) knob to obtain 0.63V AF...
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TH-K4AT/K4E ADJUSTMENT Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method Switch to Adjustment mode and carry out the operations for adjustment item D. (Refer to page 29) S-meter 3) LCD display: S1 TX-RX [MENU] Write Frequency: 435.050MHz...
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TH-K4AT/K4E ADJUSTMENT Transmitter section Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method 1.TX power Battery terminal voltage: DC power supply TX-RX Note: Do not Write (Battery 7.5V (A/3) use the DC IN Note: Adjust the output voltage from DC power supply until the voltage at the battery terminal terminal: 7.5V)
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TH-K4AT/K4E ADJUSTMENT Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method 2.TX power Connect the optional PG-2W DC power supply TX-RX DC IN Write (DC IN DC cable to the power supply. (A/3) terminal: 13.8V) DC IN terminal voltage: 13.8V...
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TH-K4AT/K4E ADJUSTMENT Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method To exit from the Adjustment DC power supply Check 4 to 6 seg- Mode, turn the transceiver ments are power OFF and then ON. lighted.
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TH-K4AT/K4E ADJUSTMENT Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method 7.Tone Switch to Adjustment mode Linear detector TX-RX deviation and carry out the operations (A/3) for adjustment item M. (Refer to page 33) Detector: P-P/2...
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TH-K4AT/K4E ADJUSTMENT Measurement Adjustment Specifications/ Item Condition Remarks Test equipment Unit Terminal Unit Parts Method 10. VOX To exit from the Adjustment TX-RX Check Does not Operation Mode, turn the transceiver (A/3) transmit. Check power OFF and then ON. 1)Frequency: 435.000MHz...
TH-K4AT/K4E PC BOARD TX-RX UNIT (X57-675X-XX) (A/3) 0-21 : M2 2-71 : E Foil side view (J72-0884-19 A/3) R101 R100 C144 C146 C140 C136 C137 R347 C369 C134 R348 C129 C131 C130 C363 R344 C326 C327 C202 C282 R164 R162...
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TH-K4AT/K4E TH-K4AT/K4E PC BOARD PC BOARD TX-RX UNIT (X57-675X-XX) (A/3) 0-21 : M2 2-71 : E TX-RX UNIT (X57-675X-XX) (A/3) 0-21 : M2 2-71 : E Component side view (J72-0884-19 A/3) Component side view (J72-0884-19 A/3) C310 POWER COM0 R246...
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TH-K4AT/K4E TH-K4AT/K4E PC BOARD PC BOARD TX-RX UNIT (X57-675X-XX) (A/3) 0-21 : M2 2-71 : E TX-RX UNIT (X57-675X-XX) (A/3) 0-21 : M2 2-71 : E Foil side view (J72-0884-19 A/3) Foil side view (J72-0884-19 A/3) R101 R100 C144 C361...
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TH-K4AT/K4E PC BOARD TX-RX UNIT (X57-675X-XX) (B,C/3) 0-21 : M2 2-71 : E Component side view (J72-0884-19 B,C/3) MIC1 MENU – 2/VFO 3/MR F/CALL CALL J72-0884-19 (B/3) MONI LAMP J72-0884-19 (C/3) Ref. No. Address Component side Layer 1 Layer 2...
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