1. Hytera Communications Co., Ltd Global Customer Service Center
TC320 Technical Training
Hytera Communications Co., Ltd
Global Customer Service Center
Edited by Adam Sun
22Feb2012

2. Content
Main Function & Feature
Technical Specification
Software & Setting
Disassembly & Re-assembly
Circuit Description & Analysis
Basic Troubleshooting

3. 1. Main Function & Feature

4. Main Function & Feature
TC320 is a economy/business two-way radio which spread to the world in 2008 with different marketing requirement.
It is unique for its compact and delicate size, and the ergonomically design will give you an exceptional experience of portability, deliver you secure, instant and reliable communications at peak efficiency.

5. Main Function & Feature
Fine shape fashion
TC-320 smooth lines, ultra-thin appearance, with the mechanical design of the human body works. As a result of the use of mitigation for a long time and have a sense of fatigue. The whole production with battery and antenna, weighs about 135g.
Easy one-hand operation
TC-320 with the fine and streamlines body, use power switches and buttons to adjust the volume. Feel very good channel knob and PPT button, users can ensure that a signal basic walkie-talkie in one-hand operation.
Mini USB socket programming/charging
TC-320 with a mini-USB interface, through HYT dedicated date lines, it can be achieved to TC-320 charge and direct programming.

6. Main Function & Feature
Scramble
Compander
Power display
High / Low Power switch
Channel spacing adjustable
Monitor
VOX
USB socket-charge/programming
Auto-saving feature
Electricity shortage warning
Busy channel lock
Launch time-out timer
Computer Programming
Wire clone

7. 2. Technical Specification

8. General Technical Specifications
Freuquency range
MHz MHz MHz
Channel capacity
16ch
Chanel space
25/12.5KHz
Frequency stability
±5ppm
Operating voltage
3.8V DC
Alert voltage (RX/TX)
3.7V/3.5V DC
Forbid TX voltage (RX/TX)
3.5V/3.3V DC
Power off voltage
3.1V DC
Dimension (lenth×width×height)
(with battery, no antenna)
100mm×48mm×27mm
Weight(with antenna and battery)
135g
Battery capacity (mAh)
1100mAh（Li-ion）
Working time
≥10 hours

9. Technical Specification
Description of positive /negative electrode
Positive electrode
Negative electrode
Negative electrode
Positive electrode for charging power
Negative electrode

10. Technical Specification
CV voltage specification and adjustment
CV voltage
High frequency
Low frequency RX
2.1±0.05V
≥0.5V TX
≤2.3V
Notes:
There is only one communal VCO for TX/RX while adjusting CV voltage. When adjust TC101, we need pay attention to TX CV voltage and RX CV voltage at same time. After adjustment, we should cover the hole with copper sheet.

11. Technical Specification
Specification and adjustment for TX TX
Frequency error
±600Hz
RF output power
≥0.2W
RF current while TX high power A
Modulated limitation for width
KHz
Modulated distortion
≤5%
Notes:
It should have a inductive test while testing the whole radio, the specification as above. TX output power for PCB testing is 2.0W/0.5W, the TX current ≤1.4A/0.8A.

12. Technical Specification
Specification and adjustment for RX RX
Receiving sensitivity
0.25uV/0.28uV
Maxium audio power
0.8W（16ohm）
the rated audio distortion
5%（0.4W）
squelch level voltage uV
Notes:
Due to external interference ,the squelch level voltage range has some deviation.

13. 3. Software & Setting

14. Software & Setting Programming Software Description
In user mode, we can set some function and parameters via programming software in PC, the operation is as following:
Install the programming software of TC320 in PC
Connect the TC-320 and PC with the programming cable, one side is USB interface of PC, the other side is Mini USB socket of TC320
Turn on the radio
Open the programming software, and read the data from the TC320
Notes:
If the radio enter the “READ” successfully, it will glitter red light, after having done it, it will extinguish red light; if the radio enter the “WRITE” successfully, it will glitter green light, after having done it , it will extinguish with green light.
During the course of programming, if there is some abnormal case or no response, it show that the programming is failure, and the PC will alert some wrong information.

15. Software & Setting Programming Software Description
The programming software of TC-320 is the same with TC-518.
Programming software latest version: HT E-V
Its download address: software).zip

16. Software & Setting
After install the programming software of TC320, click “Model” --- “Model information” ,we can select the corresponding radio type and frequency range, then can do some operations such as “READ” or “ WRITE”.

17. Software & Setting
From the function of “Buttons/Keypad”, we can set the corresponding function of “SK1”, a new function of “Channel Lock” can be set here.

18. Software & Setting
Notes: Do not enable the function of “panel test mode” and “factory clone mode”.

19. Software & Setting
From “Per Channel”, we can set some parameters such as “frequency , power level, CTCSS/CDCSS” etc.

20. Software & Setting
From the “Per personality” , we can set some special parameters of “ TX/RX”

21. Software & Setting
From “Scan”, we can set some parameters for scan personality

22. Software & Setting Wire Clone Mode The operation of wire clone mode
Connect the master radio and slave radio with clone cable, press “SK” key of master radio and turn on the radio, after 2 seconds, it will enter wire clone mode, just turn on the slave radio, it also will enter wire clone mode
In wire clone mode , we can switch user clone mode to factory clone mode via pressing “SK” key ( we should enable “factory clone mode” in programming software , or we can not switch it )
While press “PTT” key , the data from master radio will clone to slave radio, after finish it ,we can continue to clone other radios
The indication of wire clone mode
The LED will glitter red light while cloning, and it will glitter green light after finish cloning;
Slave radio：the LED will glitter green light and it will go out green light after finish cloning
The difference between “factory clone mode” and “ user clone mode”
User clone mode: only can clone the related data ( such as frequency , CTCSS etc.) in user mode, it will not clone the adjusted frequency , baseband parameters etc.
Factory clone mode: it will clone all data except “series number”
Notice
If the clone cable is not good contact, it will cause error
If the LED flash red light while cloning, the master radio will alert low voltage emergency, but the data will not stop cloning

23. 4. Disassembly & Re-assembly

24. Disassembly & Reassembly
Components Description

25. Disassembly & Reassembly
Components Description
(1) PTT key (TX key)
(2) SK key (programmable key)
(3) speaker
(4) Volume adjustable key
(5) mic
(6) Model logo
(7) Charge pole
(8) atenna
(9) Power switch
(10) Status indicator
(11) Channel slecetor switch
(12) Charge indicator
(13) Earphone plug
(14) Earphone socket
(15) Mini USB socket
(16) Belt clip
(17) Belt clip screw
(18) Battery cover
(19) Battery latch

26. Disassembly & Reassembly
Disassemble Radio
Turn off the radio
Remove the antenna
Remove the battery
Push the battery latch upward.
Remove the battery cover
Take out the battery from the bottom

27. Disassembly & Reassembly
Disassemble Radio
Disassemble the channel selector knob and nut, waterproof ring.
Remove the channel selector cover
Remove the nut
Remove the channel selector knob
Remove the nut and waterproof ring
Channel selector cover
Channel selector knob
Nut and waterproof ring

28. Disassembly & Reassembly
Disassemble Radio
Disassemble the back case and side PTT cover
Remove the four screws from the back case.
Push the back case upwards
Pull out the back case
Take out the side PTT cover

29. Disassembly & Reassembly
Disassemble Radio
Disassemble PCB
Remove the 2 screws from the PCB
Remove the steady ring from the PCB and the channel selector switch
Pay attention to the speaker line and charge pole of back case

30. Disassembly & Reassembly
Reassemble Radio
Reassemble PCB
Reassemble the MIC cover
Make sure the speaker is good contact, the installation of charge pole in back case is normal
Install the steady ring of channel selector switch and put the PCB inside it
Screw the two screws
MIC cover
Speaker cable
Steady ring of channel selector
Reassemble the model cover
Install the screw
Install ST1. 7X4 screws in the PCB

31. Disassembly & Reassembly
Reassemble Radio
Reassemble back case
Reassembly the side PTT cover
Take out the sponge and put it to right place.
Screw the four screws 2 1 3
Install 4pcs PT2.0*8.0mm screws in sequence
PTT cover

32. Installation direction
Disassembly & Reassembly
Reassemble Radio
Reassemble the top nut and cover
Install the waterproof ring to the nut
Install the nut with the waterproof ring to the main unit, and screw it tightly with a cross sleeve
Install the channel selector knob
Screw the fixed screws
Install the channel selector knob cover
Waterproof ring
Installation direction
Channel Selector Knob 5
Screw the fixed screws
Take out the protect paper. Install the cover matching the marked point
图13

33. Disassembly & Reassembly
Reassemble Radio 5
Reassemble the antenna
Install the battery and battery cover
Note
Stick copper foil

34. 5. Circuit Description & Analysis

35. Circuit Description & Analysis

36. Circuit Description & Analysis
1. RF Parts
1.1 PLL
PLL circuit generates the first local oscillator for reception and the RF signal for transmission
PLL circuit diagram

37. Circuit Description & Analysis
1. RF Parts
1.2 RF power amplifier
The demodulated carrier signal which output from VCO is pre-amplified by U501 and amplified by Q401, Q402, Q403, the amplified RF signal will be filtered by LPF to remove unwanted signal and send to antenna.Q404, Q405 and U401 are composed of APC, U401 is used to control the bias voltage of driving transistor Q402 and power amplifier FET Q403 so as to control transmitting current.
RF power amplifier circuit diagram

38. Circuit Description & Analysis
1. RF Parts
1.3 RX
The input signal from antenna is filtered by acoustic wave filter to remove unwanted signal and amplified by Q506,then enter the high frequency /low noise filter of U501 for amplifying ,the amplified signal will be second mixed, demodulated, filtered, de-emphasis, decode and D-A switch and get audio signal.
Receiving circuit diagram

39. Circuit Description & Analysis
2. MCU/Signal processing and audio amplifier

40. Circuit Description & Analysis
2. MCU/Signal processing and audio amplifier
2.1 MCU
The control circuit is composed of MCU, EEPROM.
The main function of MCU: data’s transmitting and store; checking the signal of external pressing keys, VOX-DET and process; control and switch receive /transmit; open/close the squelch circuit; output a controlling signal to control high/low switch circuit, audio amplifier circuit, VCO power supply circuit, receiving power supply circuit and transmitting power supply circuit.
2.2 Signal process
Transmitting baseband process
Receiving baseband process
2.3 Audio amplifier
The audio signal out from U601 is processed and amplified by audio amplifier IC(U301) and drive the speaker to get audio.

41. Circuit Description & Analysis
3. Power Supply
Power Supply Diagram
The power supply of 3.7V which controlled and switched by U602 and get two line 3V DC, one is VCC for CPU, the other 3V to VT and VR under the controlling of V-SAVE, also it supply V-SAVE to PLL.

42. 6. Basic Troubleshooting

43. Basic Troubleshooting
Can not power on
No voice or abnormality voice while powering on
No /low TX power
No Rx/low receiving sensitivity
Unlock while powering on
Can not charge normally

44. Basic Troubleshooting
Can not power on
Steps
Check the battery capacity is full and the battery plate is well contact with the main unit
Check the power switch is broken
Check whether pin6 of AVR IC U602 is 3V output
Check the crystal KHz for CPU is broken
Check the reset IC U605 is broken?
Check the pins of CPU is falsely-soldering
Power switch
AVRU602
Reset IC U605
32.768KHz
CPU falsely-soldering

45. The soldering of speaker line
Basic Troubleshooting
6. Basic Troubleshooting
No voice or abnormal voice while powering on
Steps
Check speaker, speaker line’s soldering is normal
Check speaker socket is broken
Check audio power amplifier IC U301（AP4890）is normal
Audio power amplifier
The soldering of speaker line
Speaker socket

46. Basic Troubleshooting
No/low TX power
Steps
Check the output voltage of Q601
Check TX current
Check the bias voltage of final power amplifier
Check the output voltage of pin4 for U501
Check power amplifier while there is current but no TX power. Check power supply for TX circuit while there is no current no power.
about 3.7V
about1.0V
Final PA RQA0002
U501
Q601

47. Basic Troubleshooting
No RX/low Receiving Sensitivity
Steps
Check the crystal of band pass filter is broken
Check filter 450KHz is loose or broken
Check the first mixer Q505 is broken
Check the IF processing of IC U501 is falsely-soldering or broken
Check the demodulator is loose or broken
IF IC U501
1st Mixer Q505
450 Filter
Crystal 21.7MHz
Band-pass filter
50C24 demodulator

48. Basic Troubleshooting
Unlock while powering on
Steps
Check CV is normal
Check the output voltage of pin85 for CPU is normal (H: lock, L: unlock)
Check the crystal of 21.25MHz is normal
Check the pins of IC U501 for PLL is falsely-soldering or broken
CPU
21.25M crystal
PLL IC U501
CV test point

49. Basic Troubleshooting
Can not charge normally
Mini USB socket
IC U604
Steps
Check the output voltage of adapter is normal
Check the Mini USB socket is normal
Check the output voltage of charging IC U604 is normal

50. THANKS
Please call or Hytera Global Customer Service Center, if you have any question about Hytera Product.
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