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SERVICE MANUAL DMR MOBILE RADIO 数 字 车 载 对 讲 机...
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Service Manual Preface This manual describes information related with product repair. To repair the product properly, please read this manual carefully. This manual is applicable to the following model: MD78X (X may indicate 2, 5, 6 or 8) MD78XG (X may indicate 2, 5, 6 or 8) Note: The description related to GPS is applicable to MD78XG only.
Service Manual 2. Copyright Information Hytera is the trademark or registered trademark of Hytera Communications Co., Ltd. (the Company) in PRC and/or other countries or areas. The Company retains the ownership of its trademarks and product names. All other trademarks and/or product names that may be used in this manual are properties of their respective owners.
No part of this manual may be copied, modified, translated, or distributed in any manner without the express written permission of us. If you have any suggestions or would like to learn more details, please visit our website at: http://www.hytera.com.
Service Manual 4. Product Overview Intended User This manual is intended for use by qualified technicians only.
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Service Manual 5. Product Controls Front Panel Part Name Part Name Volume Control / Cha nnel ○ ○ LED Indicator Selector Knob ○ ○ LCD Display OK/Menu Key ○ ○ Back Key Power On/Off Key ○ ○ Up Key Down Key ○...
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Service Manual Rear Panel Part Name Part Name ○ ○ RF Antenna Connector Power Inlet ○ ○ Accessory Jack GPS Antenna Connector Note: The GPS Antenna Connector is only available for MD78XG.
Service Manual 6. Front Panel The front panel contains the speaker, keys, power switch, volume control knob, LCD display and other parts. The block diagram is shown as the figure below. CONTROL HEAD Keys Matrix Back Switch Down Menu Keyboard Keyboard EMER 3*4 KEY...
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Service Manual and R6 respectively. The 5V voltage is converted to 3.3V by U5, in order to supply the LCD module. 4) LEDs and Backlight The LED enable signal is fed to the serial-to-parallel converter IC, and then is output by U302. RX status is indicated by green LED, and TX status by red LED.
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Service Manual 7. Baseband Section 7.1 Power Section Figure 7-1 Diagram of Power Distribution Both the baseband control IC and the RF section can convert the supplied voltage to an appropriate one via the voltage converter. Supply for RF: U914, Q920 and Q921 supply power for the RF section by high current PNP transistor and comparator, which can work as LDO (Low Dropout Regulator).
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Service Manual 7.2 Power On/Off The mobile radio can be powered on/off through any of the following methods: Power On/Off key Ignition Signal Emergency 7.2.1 Power On/Off Key Power on the radio: As the Power On/Off Key is pressed, R944 becomes grounded and Q910 is on. Then Q905 outputs high-level signal, causing U902 and Q920 to start working.
Service Manual procedures are completed. 7.3 Clock Figure 7-2 Diagram of Clock Distribution 7.3.1 Input Clock The 32K clock provided by X375 is mainly used for timing and sleeping of the system. Its frequency (32.768 kHz) is divided by U302 (32768 times in all) to 1Hz for counting seconds. The system clock (19.2MHz) is generated by an external crystal oscillator.
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Service Manual Figure 7-4 Diagram of MCSI Interface When U302 is communicating with U100, it works in Master Mode with clock frequency of up to 9.6MHz. U100 uses MCSI synchronization as chip select signal and MCSI1.DOUT as data cable to configure its register.
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Service Manual Figure 7-6 Diagram of SSI Interface U302 has a total of three McBSP interfaces: McBSP1, McBSP2 and McBSP3, compatible with various interfaces. McBSP1 is connected with I2C of the audio processor, to realize two-way transmission of digital voice and data. McBSP2 uses independent clock and frame synchronization for transmitting and receiving.
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Service Manual Figure 7-8 Diagram of UART Interface U302 has a total of three UART interfaces, which are utilized to communicate with different external devices. UART2 is used for communication with front panel and serial port on PC, while UART3 with Option Board and accessory jack (USB).
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Service Manual Relative Voltage Signal Function Remarks (VDD=3.3V) Option Board GPIO5: output signal of the option board (reset); GPIO1 GPIO GPIO4 and GPIO5: GPIO2 GPIO uni-directional GPIO3 GPIO output interfaces. GPIO4 GPIO They require their GPIO5 RESET-OUT input resistance is above or equal to VIH MIN=0.7VDD 47KΩ.
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Service Manual 7.5 Audio Section Figure 7-9 Diagram of Audio Section 7.5.1 RX Audio Circuit U302 sends digital audio to the audio processor codec via the SSI bus of MCBSP1. This bus is composed of CLKX, FSX, DX and DR. It sends the demodulated PCM audio signal to the codec, and adjusts the signal to appropriate amplitude according to the volume (RMS should be 80mv when frequency is 1 KHz and deviation is 3 KHz).
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Service Manual external MIC is connected to the MIC_HED of the codec as a unit-directional input. Both MICs are controlled by Q232. When the internal MIC is active, EXT_MIC_EN is at low level, bias voltage of external MIC is disconnected, and the ADC in U231 senses voltage at the MICIN_HND. When the external MIC is active, EXT_MIC_EN is at high level, Q232 is turned on, bias voltage is connected, and the ADC in U231 senses only audio data at MICIN_HED.
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Service Manual 7.5.3 Troubleshooting Flow Chart for Control Circuit...
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Service Manual 7.6 PCB Difference The UHF1 PCB has three versions: D, F and H. The watchdog circuit (in the figure below) is added in version F. 3V3D U910 R932 /PRST1 4.7K D913 SENCE /PRST RSET MBRM120LT1G C937 1000p C941 0.15u D912 R920...
Service Manual 8. GPS Circuit 8.1 Circuit Description Power Antenna UART OMAP module REB-1315LPx Figure 8-1 Diagram of GPS Circuit GPS positioning information can be acquired via the programmed GPS key on the front panel. The GPS function is realized via REB-1315LPx module, which integrates GPS baseband processor circuits. The GPS signal (1.57542GHz), received via the GPS active antenna (with a built-in LNA), goes to the GPS module for processing, and then enters U302 via the UART port.
Service Manual 8.4 Troubleshooting Flow Chart Replace the module. Antenna Replace the works Start antenna. normally? Peripheral Replace components work defective normally? components. The radio can position RX signal is normally? weak? Replace U901. Replace connector W321. The PC-based U901 outputs 3.3V software (e.g.SiRF Connector works normally?
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Service Manual 9. Tuning Description For details about radio tuning, please refer to the help file of DMR Tuner Software supplied by the Company.
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Service Manual 10. Interface Definition J404: to front panel jack Pin No. Name Function INT_MIC Audio input MIC_GROUND Audio input ground ACC_IO1 Accessory identifier pin 1 USB_VBUS USB power supply HOOK HOOK USB_D- USB data cable D- USB_D+ USB data cable D+ ACC_IO2 Accessory identifier pin 2 UART2_RXD_A...
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Service Manual PWB_IN Power-on/ power-off signal J4: to aviation jack of front panel Pin No. Name Function ACC_IO1 Digital input PTT_IN Digital input Handset_Audio Analog output USB_D- USB data cable Ground USB_VBUS Power supply MIC_IN Analog input USB_D+ USB data cable HOOK Hook signal input ACC_IO2...
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Service Manual RESET Reset signal Select data cable LEDA LED positive LED_K1 LED_K2 LED negative LED_K3 J403: to accessory pin jack Pin No. Name Function Vbus USB Power supply (+5V) Ground Ground GP5_3 Digital input/output SW B+ sense Power supply External Alarm Analog voltage output Power Ground...
Service Manual 11. UHF1 (400-470MHz 25W) Information 11.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual 11.1.4 Driver Power Amplifier The driver power amplifier is formed by Q804, with variable gain controlled by voltage VGG. The maximum output power is 38.5dBm, and the maximum variable gain is 11dB. 11.1.5 Final Power Amplifier The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 10dB.
Service Manual 11.1.9 Output Power Control The TX power is controlled by U801. The forward power is applied to the directional coupler, to output a voltage that can represent the forward power. The voltage together with the preset voltage feeds to U801 to output a voltage VGG, which can control both gate voltage and gain of Q804 and Q805, ensuring a constant power output.
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Service Manual electrically tunable band-pass filter to get useful signals. After passing through the RF band-pass filter and LNA (Q6102), the RF signals together with the first LO signal feed to the mixer for the first frequency conversion, to generate the first IF signal (73.35MHz). The mixer that employs the passive diode can ensure good dynamic range and port isolation.
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Service Manual The PLL synthesizer that consists of the reference oscillator (X100), PLL IC (U100) and VCO, is utilized to supply excitation signal source to the transmitter, and local oscillator signal to the receiver. 11.3.2 Reference Oscillator X100 is a 19.2MHz TCXO, and its reference frequency is calibrated by the digital-to-analog converter (U500) for accuracy.
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Service Manual oscillators. There are four VCOs in all: two VCOs (Q100 and Q103) used to transmit excitation signals and the other two VCOs (Q106 and Q110) to receive LO signals. U302 controls the operating frequency of the VCO. Q102 and Q107 constitute the buffer amplifiers for the transmitter circuit, while Q111 and Q109 for the receiver circuit.
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:11dB Gain:15 dB Tx/Rx Gain:16 dB Switch Gain:-6 dB Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual 11.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 73.35MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 3.6V. [3] Check whether the emitter voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 1.8V under normal RX/TX status.
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Service Manual 12. UHF1 (400-470MHz 45W) Information 12.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual maximum output power is 38.5dBm, and the maximum variable gain is 11dB. 12.1.5 Final Power Amplifier The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 10dB. The input matching circuit is composed of C815, C839, R804, R806, R807, R813, R818 and R861, while the power combining circuit is composed of C820, C8330, C831, C819, C812, C841 and C842.
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Service Manual The circuit consists of thermistor RT804 and resistor R884. The output voltage is proportional to the detected temperature. Both the voltage used for temperature detection and the threshold voltage are fed into the operational amplifier U803, to output a voltage signal that is in proportion to the detected temperature.
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Service Manual Figure 12-3 Diagram of IF Processor The first IF signal (73.35MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is converted to the second IF signal (2.25MHz). Then the un-demodulated digital I/Q signal output from the SSI interface is sent to U302 for demodulation.
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Service Manual Figure 12-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator goes into the PLL IC for division, generating the reference frequency. Meanwhile, the frequency generated by VCO goes into PLL IC (U100) for frequency division. The resulting frequency will be compared with the reference frequency in terms of phase difference in the phase detector.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 12-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:11dB Gain:15 dB Tx/Rx Gain:16 dB Switch Gain:-6 dB Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual 12.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 73.35MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 3.6V. [3] Check whether the emitter voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 1.8V under normal RX/TX status.
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Service Manual 13. UHF2 (450-520MHz 25W) Information 13.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual The driver power amplifier is formed by Q804, with variable gain controlled by voltage VGG. The maximum output power is 38.5dBm, and the maximum variable gain is 11dB. 13.1.5 Final Power Amplifier The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 10dB.
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Service Manual to output a voltage VGG, which can control both gate voltage and gain of Q804 and Q805, ensuring a constant power output. 13.1.10 Thermal and Over-voltage Protections The circuit consists of thermistor RT804 and resistor R884. The output voltage is proportional to the detected temperature.
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Service Manual out-of-band spurious signals, and then feed to the two-stage IF amplifier circuit (composed of Q6133 and Q6134) for amplification. Finally the amplified signals go to the IF IC for processing 13.2.2 Receiver Back-end Figure 13-3 Diagram of IF Processor The first IF signal (73.35MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is converted to the second IF signal (2.25MHz).
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Service Manual 13.3.3 PLL IC The PLL IC (U100) is a fractional frequency divider. The logic IC U101 and U102 work with the PLL IC (U100) to achieve locking. Figure 13-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator goes into the PLL IC for division, generating the reference frequency.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 13-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:11dB Gain:15 dB Tx/Rx Gain:16 dB Switch Gain:-6 dB Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual Ref. No. Part No. Description C6126 3101051890050 1.8PF 1538 C6127 3101051890050 1.8PF 1539...
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Service Manual 13.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 73.35MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 3.6V. [3] Check whether the emitter voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 1.8V under normal RX/TX status.
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Service Manual 14. UHF2 (450-520MHz 45W) Information 14.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual maximum output power is 38.5dBm, and the maximum variable gain is 11dB. 14.1.5 Final Power Amplifier The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 10dB. The input matching circuit is composed of C815, C839, R804, R806, R807, R813, R818 and R861, while the power combining circuit is composed of C820, C8330, C831, C819, C812, C841 and C842.
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Service Manual constant power output. 14.1.10 Thermal and Over-voltage Protections The circuit consists of thermistor RT804 and resistor R884. The output voltage is proportional to the detected temperature. Both the voltage used for temperature detection and the threshold voltage are fed into the operational amplifier U803, to output a voltage signal that is in proportion to the detected temperature.
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Service Manual Q6134) for amplification. Finally the amplified signals go to the IF IC for processing 14.2.2 Receiver Back-end Figure 14-3 Diagram of IF Processor The first IF signal (73.35MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is converted to the second IF signal (2.25MHz).
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Service Manual The PLL IC (U100) is a fractional frequency divider. The logic IC U101 and U102 work with the PLL IC (U100) to achieve locking. Figure 14-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator goes into the PLL IC for division, generating the reference frequency.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 14-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:15 dB Gain:11dB Tx/Rx Gain:16 dB Gain:-6 dB Switch Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual Ref. No. Part No. Description C6126 3101051890050 1.8PF 1538 C6127 3101051890050 1.8PF 1539...
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Service Manual 14.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 73.35MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 3.6V. [3] Check whether the emitter voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 1.8V under normal RX/TX status.
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Service Manual 15. UHF3 (350-400MHz 25W) Information 15.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual 15.1.4 Driver Power Amplifier The driver power amplifier is formed by Q804, with variable gain controlled by voltage VGG. The maximum output power is 38.5dBm, and the maximum variable gain is 11dB. 15.1.5 Final Power Amplifier The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 10dB.
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Service Manual voltage that can represent the forward power. The voltage together with the preset voltage feeds to U801 to output a voltage VGG, which can control both gate voltage and gain of Q804 and Q805, ensuring a constant power output. 15.1.10 Thermal and Over-voltage Protections The circuit consists of thermistor RT804 and resistor R884.
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Service Manual to get a gain (17dB). The first LO signals (73.35MHz) pass through the crystal filter (Z6100) to remove out-of-band spurious signals, and then feed to the two-stage IF amplifier circuit (composed of Q6133 and Q6134) for amplification. Finally the amplified signals go to the IF IC for processing 15.2.2 Receiver Back-end Figure 15-3 Diagram of IF Processor The first IF signal (73.35MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is...
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Service Manual (U500) for accuracy. 15.3.3 PLL IC The PLL IC (U100) is a fractional frequency divider. The logic IC U101 and U102 work with the PLL IC (U100) to achieve locking. Figure 15-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator goes into the PLL IC for division, generating the reference frequency.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 15-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:15 dB Gain:11dB Tx/Rx Gain:16 dB Gain:-6 dB Switch Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual 15.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 73.35MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 3.6V. [3] Check whether the emitter voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 1.8V under normal RX/TX status.
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Service Manual 16. UHF3 (350-400MHz 45W) Information 16.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual The driver power amplifier is formed by Q804, with variable gain controlled by voltage VGG. The maximum output power is 38.5dBm, and the maximum variable gain is 11dB. 16.1.5 Final Power Amplifier The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 10dB.
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Service Manual to output a voltage VGG, which can control both gate voltage and gain of Q804 and Q805, ensuring a constant power output. 16.1.10 Thermal and Over-voltage Protections The circuit consists of thermistor RT804 and resistor R884. The output voltage is proportional to the detected temperature.
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Service Manual out-of-band spurious signals, and then feed to the two-stage IF amplifier circuit (composed of Q6133 and Q6134) for amplification. Finally the amplified signals go to the IF IC for processing 16.2.2 Receiver Back-end Figure 16-3 Diagram of IF Processor The first IF signal (73.35MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is converted to the second IF signal (2.25MHz).
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Service Manual 16.3.3 PLL IC The PLL IC (U100) is a fractional frequency divider. The logic IC U101 and U102 work with the PLL IC (U100) to achieve locking. Figure 16-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator goes into the PLL IC for division, generating the reference frequency.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 16-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:11dB Gain:15 dB Tx/Rx Gain:16 dB Switch Gain:-6 dB Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual 16.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 73.35MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 3.6V. [3] Check whether the emitter voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 1.8V under normal RX/TX status.
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Service Manual 17. VHF (136-174MHz 25W) Information 17.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual The final power amplifier comprises Q802 and Q803, with the maximum output power of 48.5dBm, and the maximum variable gain of 14dB. The input matching circuit is composed of C815, C839, R804, R806, R807, R813, R818 and R861, while the power combining circuit is composed of C820, C8330, C833, C831, C819, C812, C841 and C842.
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Service Manual The circuit consists of thermistor RT804 and resistor R884. The output voltage is proportional to the detected temperature. Both the voltage used for temperature detection and the threshold voltage are fed into the operational amplifier U803, to output a voltage signal that is in proportion to the detected temperature.
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Service Manual 17.2.2 Receiver Back-end Figure 17-3 Diagram of IF Processor The first IF signal (44.85MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is converted to the second IF signal (2.25MHz). Then the un-demodulated digital I/Q signal output from the SSI interface is sent to U302 for demodulation.
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Service Manual (U100) to achieve locking. Figure 17-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator (X100) goes into the PLL IC (U100) for division, generating the reference frequency. Meanwhile, the frequency generated by VCO goes into PLL IC (U100) for frequency division.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 17-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:11dB Gain:15 dB Tx/Rx Gain:16 dB Switch Gain:-6 dB Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual 17.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 44.85MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer or the communication test set. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 4.3V. [3] Check whether the emitter-base voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 0.7V under normal RX/TX status.
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Service Manual 18. VHF (136-174MHz 50W) Information 18.1 Transmitter Circuit The transmitter circuit is composed of power amplifier circuit and power control circuit. The former is used to amplify the VCO signal to the desired output power level, while the latter can keep the output power at the desired level, so as to protect the power amplifier from damage caused by over heat, antenna mismatch, and out-of-range voltage (over voltage or under voltage may result in damage to Q801, Q805, Q804, Q802 and Q803).
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Service Manual the maximum variable gain of 14dB. The input matching circuit is composed of C815, C839, R804, R806, R807, R813, R818 and R861, while the power combining circuit is composed of C820, C8330, C833, C831, C819, C812, C841 and C842. 18.1.5 Antenna Switch The antenna switch is used to switch between the transmitter circuit and the receiver circuit.
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Service Manual detected temperature. Both the voltage used for temperature detection and the threshold voltage are fed into the operational amplifier U803, to output a voltage signal that is in proportion to the detected temperature. Afterwards, the voltage is applied to software for judgment, and then the preset voltage will be subsequently changed to reduce the TX power, and to protect the PA from over-heating.
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Service Manual Figure 18-3 Diagram of IF Processor The first IF signal (44.85MHz) output by the IF amplifier goes into IF IC via Pin 47, where the signal is converted to the second IF signal (2.25MHz). Then the un-demodulated digital I/Q signal output from the SSI interface is sent to U302 for demodulation.
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Service Manual Figure 18-4 Diagram of PLL IC The 19.2MHz frequency generated by the reference oscillator (X100) goes into the PLL IC (U100) for division, generating the reference frequency. Meanwhile, the frequency generated by VCO goes into PLL IC (U100) for frequency division. The resulting frequency will be compared with the reference frequency in terms of phase difference in the phase detector.
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Service Manual TX_L_VCO Q103 TX PA Q102 Q107 Q100 TX_H_VCO PLL IC (U100) RX_L_VCO Q110 RX Lo Q109 Q111 Q106 RX_H_VCO Figure 18-5 Diagram of VCO...
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MD78X/MD78XG Block Diagram (RF Section) High Temperature Protection 9V1A_TX Gain:10 dB Gain:15 dB Gain:11dB Tx/Rx Gain:16 dB Gain:-6 dB Switch Tx_PORT Microstrip Attenuator Match Match Match Matcher Microstrip Dual Q804 Harmonic Q805 Q801 Rx_PORT Directional Coupler Driver Filter PreDriver Firststage Switch s Power 9.1V Q802 Q803...
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MD78X/MD78XG Block Diagram (BB Section) IF processor RF Unit BB Schematic Block Diagram TX RX CTL MCSI1 McBSP2 GPIOs TEMP_DET Audio Codec Nor FLASH and pSRAM Headset McBSP1 FLASH: 8Mx16 Driver datax16 pSRAM:2Mx16 TMS320C55x BELL Driver Speed:96MHz(max) Mobile SDRAM McBSP3 128Mb:8Mx16 JTAG JTAG...
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Service Manual 18.8 Troubleshooting Flow Chart Receiver Circuit...
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Service Manual Description of Normal Situations: [1] During sensitivity test, use a communication test set to demodulate the audio signal (TP4012 and TP4016). If the signal is demodulated normally, it is concluded that the front panel is defective. [2] Use the communication test set to input a 44.85MHz IF signal at the mixer, and see whether it can be processed normally afterwards.
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Service Manual Description of Normal Situations: [1] The current in analog mode is above 6A under 45W power supply and above 1A under 5W. However, in digital mode, the current will be reduced by 50%. [2] The APC voltage should be above 2V at TP811. [3] Check whether there is an appropriate TX LO signal at TP803.
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Service Manual Description of Normal Situations: [1] Detect the oscillation frequency of RX TP123 and TX TP111 using a spectrum analyzer or the communication test set. [2] Check whether switches (Q108, Q112, Q101 and Q105) are turned on and output 4.3V. [3] Check whether the emitter-base voltage of the four transistors (Q106, Q110, Q100 and Q103) is about 0.7V under normal RX/TX status.
Service Manual 19. Disassembly and Assembly Disassembly 1. Turn off the radio and remove the power cord and antenna. 2. Loosen the three screws to remove the front panel. Then remove the FFC. 3. Detach the volume control knob and loosen the four screws. Then remove the PCB from the control panel.
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Service Manual 6. Loosen the screw fixing the antenna connector and two screws fixing the PA module. Then take the PCB out. Assembly To assemble the radio, perform the above steps in a reverse way. In addition, the following procedures shall be performed: 1.
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Service Manual 4. Connect the palm microphone to the radio (via front-panel connector). When the palm microphone is not in use, hang it on the microphone hanger.
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Service Manual Part Number Description Qty. 6300109000000 Aluminum chassis (RoHS) 7500358000000 Heat sink pad (RoHS) 6100492101000 Waterproof ring for front case (RoHS) 4210090000200 Signal cable (RoHS) 5208010100010 Connector (male) 10Pin (RoHS) 6001079000000 Light-guide plate for keys (RoHS) 7300048000000 Metal dome (RoHS) 6100408001000 Waterproof ring for microphone jack (RoHS) 6100488000000...
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Service Manual 6100530100000 Waterproof ring for power socket (RoHS) 5205002100110 Power socket (male) (RoHS) 3103994770150 Electrolytic capacitor (RoHS) 7212002500000 Nut (RoHS) 6100531100000 Waterproof ring for antenna connector (RoHS) 4401000009000 BNC RF connector (RoHS) 6100494000000 Soft stopple for GPS antenna connector (RoHS) 7500159000100 Thermal conductive silicone rubber (RoHS) 7500357000000...
Service Manual 22. Specifications General UHF1: 400-470MHz UHF2: 450-520MHz Frequencies UHF3: 350-400MHz VHF: 136-174MHz Channel Capacity 1024 Zone Capacity (each with a maximum of 16 channels) Channel Spacing 12.5 KHz /20KHz/25 KHz* Operating Voltage 13.6 V ±15% Standby < 0.6A Receive <...
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Service Manual ±5.0KHz@25KHz* -40dB@12.5KHz FM Hum & Noise -43dB@20KHz* -45dB@25KHz* 60dB@12.5KHz Adjacent Channel Power 70dB@20/25KHz* Audio Response +1 ~ -3 dB Audio Distortion ≤3 % Digital Vocoder Type AMBE++ or SELP Digital Protocol ETSI-TS102 361-1,- 2,-3 Receiver 0.3μV (12dB SINAD) Analog 0.22μV (Typical) (12dB SINAD) Sensitivity...
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Service Manual American Military Standard MIL-STD-810 C/D/E/F Dust & Water Intrusion IP54 Standard Humidity Per MIL-STD-810 C/D/E/F Standard Shock & Vibration Per MIL-STD-810 C/D/E/F Standard GPS (for MD78XG only) Accuracy specs are for long-term tracking(95th percentile values>5 satellites visible at a nominal -130dBm signal strength) TTFF (Time To First Fix) Cold <1 minute...
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是海能达通信股份有限公司的商标或注册 商 标 is the trademark or registered trademark of Hytera Communications Corp., Ltd. Hytera Corp., Ltd. All Rights Reserved. 2011 Hytera Corp., Ltd.版权 所有 地址:深 圳市高 新技术 产业园 北区北 环路 好易通大厦 Address: HYT Tower, Hi-Tech Industrial Park North, Beihuan 邮...
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