1. Manuals
  2. Brands
  3. Abell Manuals
  4. Radio
  5. A520T
  6. Service manual

Abell A520T Service Manual

Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
A520T（UHF）Service Manual V.1   
A520T (UHF) Service Manual
ABELL INDUSTRIES CO., LTD.
1/42

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the A520T and is the answer not in the manual?

Questions and answers

Related Manuals for Abell A520T

Summary of Contents for Abell A520T

  • Page 1 A520T（UHF）Service Manual V.1    A520T (UHF) Service Manual ABELL INDUSTRIES CO., LTD. 1/42...

  • Page 2: Table Of Contents

    A520T（UHF）Service Manual V.1    CONTENT CHAPTER 1 INTRODUCTION ............................4 1.1 SCOPE OF APPLICATION .............................. 4 1.2 SECURITY ISSUES ................................4 CHAPTER 2 STRUCTURE AND KEY FUNCTIONS ......................5 2.1 STRUCTURE ..................................5 CHAPTER 3 REALIGNMENT MODE ..........................7 3.1 MODE ....................................7 3.2 HOW TO ENTER EACH MODE ............................
  • Page 3 A520T（UHF）Service Manual V.1    8.2 APPENDIX 1 MATERIAL LIST（ ELECTRONIC PART） ..................28 8.3 APPENDIX 2 MATERIAL LIST（STRUCTURE PART） ..................34 FIG.1 A520T BIT MAP ................................. 37 FIG.2 A520T SCHEMATIC DIAGRAM ..........................39 FIG.3 A520T SCHEMATIC DIAGRAM ..........................40 FIG.4 BLOCK DIAGRAM ..............................40 FIG.5 A520T PACKING ................................

  • Page 4: Chapter 1 Introduction

    Two way radios can produce and emit electromagnetic energy to, and electromagnetic transmission safety design of ABELL two way radio completely conforms with national and international standards. In order to ensure the best communication effect of two way radio and the electromagnetic transmission safety for human, when you use two way radios for communication, please keep the two way radio perpendicular to the ground, and your month away from microphone 2.5-5 cm.

  • Page 5: Chapter 2 Structure And Key Functions

    A520T（UHF）Service Manual V.1    Chapter 2 Structure and key functions 2.1 Structure ① Antenna ② PTT button Press this button to make a call through the microphone.Release it to listen. 5/42...
  • Page 6 A520T（UHF）Service Manual V.1    ③ Short-cut programmable function keys： These keys are programmable function key such as long key (key-press time should reach the time we set for long key) and short key (normal key), which can be set for different functions. Press it to enable programmable auxiliary functions.

  • Page 7: Chapter 3 Realignment Mode

    A520T（UHF）Service Manual V.1    Chapter 3 Realignment mode 3.1 Mode Tuning mode PC mode User mode Mode type Function User mode This mode is used for general operation Tuning mode Enter tuning mode through program software Make programming setting for the radio by...

  • Page 8: Pc Mode

    Do not press [PTT] key, during the data transmitting or receiving.  Description of programming cable( programming cable: optional component) Programming cable is used for connecting A520T and PC. That is, the PC programming cable connects the A520T side socket with USB of the computer ...

  • Page 9: Chapter 4 Disassembly Parts

    A520T（UHF）Service Manual V.1     Use PC for programming If transmitting data from PC to radio, the setting destination data (basic communication parameters) can all be modified. as the value is automatically generated in setting frequency range(frequency type), generally it is not necessary to change destination data.
  • Page 10 A520T（UHF）Service Manual V.1    4. Remove antenna 5. Pull out volume and channel knob 9. Tilt up the middle aluminium box 6. Remove waterproof screw nut and pull it out 7. Remove waterproof ring 8. Remove 2 screws 10.Remove the screws of PCB 11.Lift up the PCB and remove it...

  • Page 11: Explosive View

    A520T（UHF）Service Manual V.1    4.2 Explosive view 11/42...

  • Page 12: Chapter 5 Unit Circuit Introduction

    A520T（UHF）Service Manual V.1    Chapter 5 Unit circuit introduction 5.1 DMR digital circuit diagram 4FSK digital signal diagram： （1）Via MIC, voice comes into NJM2904V, being amplified; After that DSP digital signal is processed to 4FSK digital modulating signal, which are sent to VCO and crystal modulator by two ways as MDO1/MOD2, then sent out by transition circuit.

  • Page 13: Receiving Part

    A520T（UHF）Service Manual V.1    SCT3258TD ANT SW Frame Header/Vaild IP data port Date SINGLE CHIP RDA1846 Demodulation TRANSCEIVER FOR Audio AD/DA switch WALKIE TALKIE Frame Decoding Codec Modulation Frame Encoding WM8758B 26MHz TCXO 5.3 Receiving part Front-end RF amplifier The signal received from the antenna enters the low pass filter and the Rx/Tx switch diode circuit (D5 and D6 are disconnected), by filtering out unwanted signals by L15 bandpass filter then into the RF amplifier Q6.

  • Page 14: Transmitting Part

    A520T（UHF）Service Manual V.1    5.3 Transmitting part RF power amplifier The RF signal generated from U9 passes through the front-amplifier Q8 to amplifier, and then amplified again by the drive amplifier Q4 and sent to the final power amplifier Q3 with an output of 4.5W (when the radio is set at high power, the RF power amplifier output is 4.5W, and the RF power amplifier output is 1W when the radio is...

  • Page 15: Frequency Synthesizer/Baseband Processor

    A520T（UHF）Service Manual V.1    5.4 Frequency synthesizer/Baseband processor U9 processing chip includes a PLL, VCO, mixer,IF AMP. baseband processor. (Chart 4) AF O UT P G A Core RF IN 0/90 Audio filter Sub CH filter F M m odem AF C loop...
  • Page 16 A520T（UHF）Service Manual V.1    the (U301) chip. The DQT data is generated internally by the audio baseband processor U302, and the signal enters the X2 clock crystal for modulation through the optimized waveform of CR low-pass filter. The DQT frequency offset is adjusted internally by the audio baseband processor U302.

  • Page 17: Power

    A520T（UHF）Service Manual V.1    5.5 Power The input 7.5V from J1 is regulated by U313 to output 3.6V, then U312 regulates the output DSP3V3 to provide power to U300 CPU and X2 crystal, and U313 regulates the output D3V3 to provide power to U9 RD1846S.
  • Page 18 A520T（UHF）Service Manual V.1    U317 S-80122ANMC U318 24C512 RESET RESET EEPRO M U300 PT T ST M32F 103VBT 6 XO UT PT T X300 12. 228MHz MONI XI N MONI Battery low voltage warning Battery voltage is monitored through the U300 microprocessor. Low battery tone will sound when it falls below the low battery alarm voltage.

  • Page 19: Charter 6 Functions And Parameter Setting

    6.1 Main function 6.1.1 Channels This radio(A520T) can store 32 channels, zone capacity of 2, each zone of 16 channels. 6.1.2 Scan In standby mode, press [Scan] to enter the scan state. The radio will enter the scanning state and the LED light flash green.

  • Page 20: Power Saving

    A520T（UHF）Service Manual V.1    6.1.3 Power saving To save battery power and extend standby time. Users can turn on this function by programming software. Power saving mode is entered 8 seconds after power on or 8 seconds after no operation and no call.

  • Page 21: Make Calls

    A520T（UHF）Service Manual V.1    When transmitting, indicator LED is red. When receiving, indicator LED is green. Receiving and reply group call To receive/reply calls from a user group, the radio must be configured to belong to that communication group.  The LED is green.
  • Page 22 A520T（UHF）Service Manual V.1    Using channel select knob to make calls Make group call To make group call from a user group, the radio must be configured to belong to that communication group. Steps:  Rotate the channel knob ,using the active communication group ID to select a channel.

  • Page 23: Low Battery Warning

    A520T（UHF）Service Manual V.1     Press the PTT key to initiate the call. The LED lights is red.  Wait for the prompt tone to end (if activated), then speak clearly into the microphone.  Release the PTT key to listen. When the target radio replies, the LED lights green.

  • Page 24: Prompt Tone Turn On/Off

    A520T（UHF）Service Manual V.1    6.2.4 Prompt Tone Turn On/Off If necessary, you can turn on/off radio prompt tone, except emergencycall prompt tone. Steps:  Press pre-programmed function key.  You will hear a “beep” tone, which means prompt tone function turned on; radio prompt tone turned off when you hear a “beep beep”...

  • Page 25: Chapter 7 Radio Tuning

    A520T（UHF）Service Manual V.1    Chapter 7 Radio Tuning 7.1 The required test equipment Stabilized power supply  The out power can be adjusted from 5V to 15V, and its current is 3A or even bigger.  The standard voltage is 7.5V. DC Ammeter ...
  • Page 26 A520T（UHF）Service Manual V.1    CH:3 452．500 452．500 CH:4 470．000 470．000 Chart2 Adjustment QT List Frequency UHF 400-480 MHz Signaling QT(wide band) QT(narrow band) number 67 Hz 67 Hz 127.3Hz 114.8Hz 136.5Hz 136.5Hz 206.5Hz 206.5Hz 241.8Hz 241.8Hz Note:  Connect radio with PC.

  • Page 27: Chapter 8 Parameters

    A520T（UHF）Service Manual V.1    Chapter 8 Parameters 8.1 Specifications General Model A520T UHF：350-400MHz 400-480MHz 450-520MHz Frequency range Channel capacity Channel spacing ANA: 25KHz/12.5KHz DIG:12.5KHz Working temperature -25°C~＋60 °C Working voltage 7.4VDC Antenna impedance 50Ω 2.2KΩ Microphone impedance Battery Li-ion DC 7.4V 2200mAh (optional) Dimension 132mm×54 mm×30mm...

  • Page 28: Appendix 1 Material List（ Electronic Part

    A520T（UHF）Service Manual V.1    ≦ 5% Audio distortion Frequency stability ±2.5 ppm Max. frequency deviation 25K 5 kHz 12.5K 2.5 kHz ≦ ≦ 8.2 Appendix 1 Material list（ electronic part） AMOU MATERIAL CODE DESCRIPTION BIT no./MODEL CHIP Chip resistor 0R +/-5% 0201 1/20W YAGEO...
  • Page 29 A520T（UHF）Service Manual V.1    Chip resistor 4K7 +/-5% 0201 1/20W YAGEO 151-147221Y1-010 R27 R92 R100 R349 R350 R374 R375 RC0201JR-074K7 Chip resistor 5K6 +/-5% 0201 1/20W YAGEO 151-156221Y1-010 R101 RC0201JR-075K6 Chip resistor 6K8 +/-5% 0201 1/20W YAGEO 151-168221Y1-010 RC0201JR-076K8 Chip resistor 8K2 +/-5% 0201 1/20W YAGEO...
  • Page 30 A520T（UHF）Service Manual V.1    Chip resistor 0.390R +/-1% 1206 YAGEO 151-13901541-011 R87 R88 R89 RL1206FR-070R39L Chip thermistor NTC 47K +/-5% 4050K 0603 Murata 173-47343K61-010 NCP18WB473J03RB Chip ceramic capacitor COG 22pF +/-5% 0201 50V 081-12206151-040 C58 C62 murata GRM0335C1H220J Chip ceramic capacitor COG 47pF +/-5% 0201 50V...
  • Page 31 A520T（UHF）Service Manual V.1    muRata GRM1555C1H4R0B Chip ceramic capacitor COG 47P +/-5% 0402 50V 081-14706251-040 murata GRM1555C1H470J Chip ceramic capacitor COG 470P +/-5% 0402 50V 081-14716251-040 C16 C17 C19 C395 C396 muRata GRM1555C1H471J Chip ceramic capacitor X7R 10nF +/-10% 0402 25V 081-41037241-040...
  • Page 32 A520T（UHF）Service Manual V.1    Chip bead 300mA 0402 600R murata 231-03A26011-010 L31 L302 L305 L306 L307 L311 BLM15AG601SN1 Chip bead 500mA 0603 600R murata 231-05A36011-010 L300 L301 L303 BLM18AG601SN1 231-06042201-010 Chip bead 6A 0805 22R murata BLM21PG220SN1D L7 L8 L309 Multilayer chip inductor 3.3nH +/-0.3nH 0603 TDK...
  • Page 33 331-26005321-020 +/-2.5PPM 3.2*2.5mm 50C-A520T001-011 Battery connectorA520T J404 60C-A780T003-011 Shield case A780T 19.2*14.8*0.2t PCB A520T UHF SV4 P4G235009A0S 464-520T1301-S04 102.5*46.9*1.3T Welding 801-A520TD08-001 PCBA A520T(D08) To be ensure PCB keypad A520T KEY SV2 PN 38*11.9*0.6T MICpin COB636P-2042-00-AA-H D6*3.6mm 42dB 391-26036422-010 2.0V 33/42...

  • Page 34: Appendix 2 Material List（Structure Part

    Shoulder beltA520T PC2805 To-be-sure Ear mic cover A520T TPU85 To-be-sure Earphone inner cover A520T TPU85 Rubber: To-be-sure Function key A520T silica gel 60 To-be-sure Waterproof ring A520T silica gel 40 On the aluminum case To-be-sure light A520T silica gel 60 546-00A81001-012...
  • Page 35 A520T（UHF）Service Manual V.1    To-be-sure LOGO A520T "ABELL" PC 29.5*6.1*0.3t To-be-sure Label A520T "A520T"PC 10.8*4.3*0.3t To-be-sure Type labelA520T 34.5*29.7mm 742-00A60001-011 Frequency label A-600 12*5mm) A520T 749-000ALL01-011 Serial NO.label22*5mm Ingredients: 1.07mL FL2-A005 703 sealant Speaker/mic /pcs package 803-A520TD08-001 Radio bodyA520T(D08) 803-A520TD08-002 Radio body A520T(D08)
  • Page 36 A520T（UHF）Service Manual V.1    816-00AMMS00-001 Speaker MIC AM-MS HRE-160M 815-00ADCS00-001 Programming cable AD-CS 小头 ABELL 815-00ADUS00-001 Programming cable AD-US 小头 ABELL 815-0ADUSE01-001 Programming cable AD-US-E01 RPC-TC500-U 64、32 Car-chargeradapterCJ-51-02 92*33*27mm 824-CJ510200-001 DC12V/24V 2A CW404 36/42...
  • Page 37 A520T（UHF）Service Manual V.1    FIG.1 A520T Bit map TOP side： 37/42...
  • Page 38 A520T（UHF）Service Manual V.1    BOT side 38/42...
  • Page 39 A520T（UHF）Service Manual V.1    FIG. 2 A520T Schematic Diagram 39/42...
  • Page 40 A520T（UHF）Service Manual V.1    FIG.3 A520T Schematic Diagram FIG.4 Block Diagram 40/42...
  • Page 41 A520T（UHF）Service Manual V.1    41/42...
  • Page 42 A520T（UHF）Service Manual V.1    FIG.5 A520T Packing 1.Radio body 2.Battery 3.Antenna 4.Belt clip 5.Charger adapter 6.Charger 7.Hand strap 8.blister box 42/42...

Table of Contents