HYT TC-320 User manual

TC-320 Service Manual
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Contents
Introduction........................................................................................................................3
Safety Information .............................................................................................................3
Radio Overview..................................................................................................................4
Software Specifications.....................................................................................................6
Circuit Description.............................................................................................................9
CPU Pins...........................................................................................................................13
TC-320 Parts List 1...........................................................................................................17
TC-320 (400-420MHZ) Parts Change Record.................................................................26
TC-320 (450-470MHZ) Parts Change Record.................................................................39
Adjustment Description ..................................................................................................43
Troubleshooting Flow Chart ...........................................................................................52
Disassembly and Assembly for Repair..........................................................................55
Exploded View..................................................................................................................59
TC-320 Parts List 2...........................................................................................................60
Packing.............................................................................................................................62
TC-320 VF PCB View Top Layer......................................................................................63
TC-320 VF PCB View Bottom Layer................................................................................64
TC-320 VG PCB View Top Layer.....................................................................................65
TC-320 VG PCB View Bottom Layer...............................................................................66
TC-320 Level Diagram.....................................................................................................67
TC-320 Block Diagram.....................................................................................................68
TC-320 Schematic Diagram(RF) .....................................................................................69
TC-320 Schematic Diagram(CPU)...................................................................................70
TC-320 (U1) VF Schematic Diagram(PLL)......................................................................71

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TC-320 (U1) VG Schematic Diagram(PLL) .....................................................................72
TC-320 (U2) VF Schematic Diagram(PLL)......................................................................73
TC-320 (U2) VG Schematic Diagram(PLL) .....................................................................74
Specifications...................................................................................................................75

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Introduction
Manual Scope
This manual is intended for use by experienced technicians familiar with similar types of communication equipment. It
contains all service information required for the equipment and is current as of the publication date.
Safety Information
◇This radio shall be serviced by qualified technicians only.
◇Only use HYT supplied or approved batteries and chargers.
◇To avoid electromagnetic interference and/or compatibility conflicts, turn off your radio in any area where posted
notices instruct you to do so. Turn off your radio before boarding an aircraft. Any use of the radio must be in
accordance with airline regulations or crew instructions.
◇For vehicles with an air bag, do not place a radio in the area over an air bag or in the air bag deployment area.
◇Turn off your radio prior to entering any area with explosive and flammable materials.
◇Do not charge or replace your battery in a location with explosive and flammable materials.
◇Turn off your radio before entering a blasting area.
◇Do not use any portable radio that has a damaged antenna. If a damaged antenna comes into contact with your
skin, a minor burn may result.
◇Do not expose the radio to direct sunlight for a long time, nor place it close to a heating source.
◇When transmitting with a portable radio, hold the radio in a vertical position with the microphone 2.5 to 5.0
centimeters (one to two inches) away from your lips. Keep antenna at least 2.5 centimeters (one inch) away
from your body when transmitting.
◇If you wear a portable radio on your body, ensure that the antenna is at least 2.5 centimeters (one inch) away
from your body when transmitting.

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Radio Overview
(1) PTT (Push-to-Talk) Key (2) SK (Programmable key) (3) Speaker (4)Volume Control Keys
[+] / [-]
(5) Microphone (6) Nameplate (7) Charging Terminal (8) Antenna
(9) Power On/Off Key (10) Channel/Status Indicator (11)Channel Selector Knob (12) Charge Indicator
(13)Accessory Jack Cover (14) Audio Accessory Jack (15) Mini USB Jack (16) Strap Hole
(17) Screw of Belt Clip (18) Belt clip (19) Rear Cover (20) Battery Latch
PTT (Push-to-Talk) Key
Press and hold down the PTT key to transmit, and release it to receive.
SK (Side Key)
Side Key can be programmed with long/short press functions by your dealer.

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Note: Short Press means key press no longer than 1 second, and Long Press means key press longer than 1 second.
Channel/Status Indicator
Status indications and alert tones are shown in the table below:
Operations/Functions LED Indications and Alert Tones
Wired Clone
To enter Wired Clone mode
Hold down both SK and Power On/Off Key, and then the
source radio is turned on with red LED flashing once.
Turn on the target radio directly.
Status of the source radio (After
target radio is turned on and
cloning cable is connected, press
PTT of source radio to begin
cloning.)
Red LED glows during cloning process.
Error occurs during cloning:
a. User Clone: Once cloning begins, frequency band and
Model ID will be checked. LED glows orange for 2
seconds and then goes out to indicate a failed check.
If the check is successfully carried out but error occurs
during cloning, LED will keep flashing orange until you
press any key other than the Power On/Off Key to
cancel it.
b. Factory Clone: If error occurs during cloning, LED will
keep flashing orange until you press any key other
than the Power On/Off Key to cancel it.
Once cloning is completed, green LED solidly glows.
Red LED will flash if battery runs low when the radio is in
Clone Mode, while the radio will make no response if battery
runs low during cloning process.
Status of the target radio
LED solidly glows green when cloning is in progress.
Green LED goes out when cloning is completed.
Power On (to enter User Mode)
When the radio is turned on, an alert tone sounds and orange
LED flashes once.
When the radio is currently on a blank channel, it sounds beep
tone continuously.
Power Off When the radio is turned off, the power off alert tone is heard.
Low Battery Alert LED flashes red, and a low-pitched tone sounds at intervals of
10 seconds.
Transmitting
Red LED solidly glows.
When TOT timer expires, the radio sounds beep tone
continuously.
A TOT pre-alert tone sounds before TOT timer expires.
Receiving LED glows green when carrier is present.
Scan
Green LED flashes once every 1 second, while scanning is in
process.
Scan Start Alert (programmable by the dealer): a beep is
heard.
Scan End Alert (programmable by the dealer): a beep is heard.
Writing/Reading Data Red LED glows when reading data.

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Green LED glows when writing data.
Adjust Power Level
A low-pitched tone is heard when the radio is switched to low
power.
A high-pitched tone is heard when the radio is switched to high
power.
VOX One beep is heard when the VOX feature is activated.
Two beeps are heard when the VOX feature is disabled.
Channel Selector Knob
Rotate the knob to select your desired channel.
Power On/Off Key
Long press the Power On/Off Key until an alert tone is heard to turn the radio on/off.
Volume Control Keys [+] / [-]
Battery Latch
Used to secure or remove the battery.
Audio Accessory Jack
Used to connect audio accessories such as earpiece and microphone.
Mini USB Jack
To connect accessories such as programming cable, cloning cable and switching power.
Software Specifications
Description of Features
1. Channel Capacity: 16
2. Channel Spacing: 25KHz/12.5KHz
3. Channel Scan
4. Rx/Tx status indication (red/green LED)
5. CTCSS/CDCSS Encode&Decode (38 groups of CTCSS, 83 groups of CDCSS, and CTCSS Tail Revert of 180
degrees.)
6. Low Battery Alert
7. Battery Save
8. Unlock Detection and Emergency Alarm
9. Two Selectable Squelch Levels
10. Monitor
11. Time-out Timer (TOT)
12. Squelch Tail Elimination
13. PC Programming (manual/ automatic adjustment)
14. High/Low Power Switch (2.0/0.5W)
15. Wide & Narrow Bandwidth Compatible
16. Busy Channel Lockout (transmission prohibited in busy status)
17. Wired Clone
18. Battery Strength Indicator
19. Manual Adjustment
20. VOX and Three Selectable Sensitivity Levels

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Description of Modes
User Mode
It is a conventional communication mode. After the radio is turned on, it enters the User Mode.
PC Programming Mode
The radio will enter PC Programming Mode through communication with PC programming software. In this mode, radio
functions and adjustment parameters can be set through programming software (including User Version and Factory
Version).
The operation procedures are as follows:
1) Install PC programming software and its driver dedicated for TC-320 before your initial use.
2) Connect the USB port of PC with the Mini USB jack of the radio using a programming cable.
3) Turn on the radio.
4) Launch the programming software to perform reading or writing operation.
Note:
1) When reading/writing data is in progress, red/green LED glows; when reading/writing data is completed, LED goes
out.
2) During the operation, if any abnormal situation occurs or no reply is given within a period, the reading/writing
operation will fail and an error message window will pop up.
Wired Clone Mode
1. Description
Wired Clone Mode is an independent mode. To access other modes, you must restart the radio.
Wired Clone Mode covers User Clone mode and Factory Clone mode.
1) User Clone Mode:
Connect two radios using a clone cable. Hold down both SK and Power On/Off Key of the source radio, it will be
turned on and will enter User Clone Mode after 2 seconds. The target radio can be directly turned on to enter the
mode. In this mode, parameter data stored in EEPROM of the source radio will be cloned to EEPROM of the target
radio. The data transferred only covers channel data and common parameters, excluding adjustment data, version
and serial No. of the model.
2) Factory Clone Mode:
Connect two radios using a clone cable. Hold down both SK and Power On/Off Key of the source radio, it will be
turned on and will enter User Clone Mode by default after 2 seconds. Press SK afterwards to switch to Factory Clone
Mode. The target radio can be directly turned on to enter the mode. The data transferred covers all data in EEPROM
other than serial No, with flag of manual adjustment switch included.
2. Process
Process of Wired Clone:
1) Red LED flashes once after the source radio enters Wired Clone Mode. Press PTT to clone data to the target radio.
2) During communication, the source radio glows red LED, and the target radio glows green LED. When communication
ends, the source radio glows green LED and LED of the target radio goes out, which indicates both radios are ready
for another cloning.
3) If any abnormal situation occurs during communication, the source radio will flash orange LED and will stop
communication for another cloning.
4) When the communication ends, the source radio goes back to standby status. Press PTT again to begin another
cloning.
Manual Adjust Mode
Hold down PTT, SKand Power On/Off Key to turn the radio on and to enter Manual Adjust Mode. (Note: This operation is
subject to the option Panel Test Mode in the programming software. When this option is unchecked, the radio will be
unable to enter the adjustment mode. It helps avoid change of parameters and degradation of radio performance caused

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by user’s misoperations. )
Keep this option unchecked after values are well adjusted from factory, to avoid any unexpected change of values. The
adjustment values can be reset and changed in Factory Mode only.
Description of adjustment:
1) To enter Manual Adjust Mode
Hold down PTT, SK and Power On/Off Key until the radio is turned on and orange LED glows, the radio will enter Adjust
Mode. When the keys are released, the radio will enter item N of Tx group (N depends on the position where the Channel
Selector Knob locates). Red LED glows for adjustment of Tx group items and green LED glows for adjustment of Rx
group items.
2) To switch between Tx group and Rx group
This operation is done through the Channel Selector Knob.
Red LED solidly glows when adjusting items in Tx group.
Green LED solidly glows when adjusting items in Rx group.
3) To switch between items of Tx group/Rx group
This operation is done through the Channel Selector Knob.
Tx group: CH1 to CH9 stand for Tx Low Power, Tx High Power, CDCSS Balance, CDCSS Deviation, CTCSS Deviation
(low), CTCSS Deviation (medium), CTCSS Deviation (high), Tx Low Voltage Threshold and Max. Deviation of Tx Audio
respectively.
Red LED solidly glows when adjusting items CH1 to CH9.
Rx group: CH10 to CH12 stand for SQL On 5, SQL Off 5, and Rx Low Voltage Threshold respectively.
Green LED solidly glows when adjusting items CH10 to CH12.
CH13 to CH16 are invalid and carry no adjustment item.
4) To switch between wide and narrow bandwidth
When adjusting a certain item, short press SK (orange LED flashes indicating valid press) to switch between wide/narrow
bandwidth. After this operation, the first frequency of current bandwidth is the frequency for adjustment by default.
5) To switch frequency
Short press (no longer than 1 second) PTT (green LED flashes indicating valid press) to switch frequency one by one,
under certain bandwidth and certain adjustment item.
6) To add/subtract adjustment value
Short press [+] under certain bandwidth and certain tuning item, and the adjustment value will increase in steps of 1; hold
down [+], and the adjustment value will keep increasing in steps of 1. The adjustment value will remain unchanged once it
reaches the allowed maximum value.
Short press [-] under certain bandwidth and certain tuning item, and the adjustment value will decrease in steps of 1; hold
down [-], and the adjustment value will keep decreasing in steps of 1. The adjustment value will remain unchanged once it
reaches the allowed minimum value.
7) Measures on special items:
Tx group: CH8 is the Tx Low Voltage Threshold. This adjustment item is related to AD sampling. Press [+] or [-] after
entering the above item, to activate AD sampling (including calculation) once. Rotate the Channel Selector Knob to save
the current AD sampling value. If [+] and [-] are not pressed, neither the adjustment value will be updated, nor will AD
sampling be activated.
Rx group: CH10 to CH12 stand for SQL On 5, SQL Off 5, and Rx Low Voltage Threshold respectively. These adjustment
items are related to AD sampling. Press [+] or [-] after entering the above items, to activate AD sampling (including
calculation) once. Rotate the Channel Selector Knob to save the current AD sampling value. If [+]and [-] are not pressed,
neither the adjustment value will be updated, nor will AD sampling be activated.
8) Description of key press:
Short press: key press no longer than 1 second; Long press: key press time longer than 1 second.

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Circuit Description
1. General Diagram
Tx Section: Audio signal from MIC is sent to the RF chip (U501) directly. In U501, the signal is amplitude limited and
amplified, and then sent to the MCU chip (U601). The baseband signal processing circuit in U601 will convert the
amplified audio signal to digital signal via A/D conversion, and then convert the digital signal to modulation signal via D/A
conversion after processing such as filtering, signal compression, encryption, pre-emphasis, Tx gain control and
amplitude limiting are completed. The modulation signal from MCU will pass through the low-pass filter circuit and then
will go to VCO for direct frequency modulation. The modulated carrier signal is converted to RF signal by the buffer
amplifier (U501), and then enters front-stage power amplifier (Q401) for amplification. The amplified RF signal will be
further amplified by the pre-driver (Q402) and final-stage power amplifier (Q403), and then will enter low-pass filter circuit
through the switching diode (D401), and will be finally transmitted via antenna after ultroharmonics are removed. D402
and D501 compose the Rx-Tx switch circuit.
Rx section: Desired and undesired RF signals received via the antenna are fed to the bandpass filter (composed of
SAWF501 and SAWF502) to filter out undesired out-of-band interference signal, and then amplified by the RF amplifier
(Q506). The amplified signal is then fed to the bandpass filter (SAWF503) to filter out undesired out-of-band interference
signal. The desired RF signal is mixed with the first local oscillator signal (output from VCO) by Q505. The newly
generated signal is processed by the crystal filter (XF501) to get the first IF signal (desired signal). After being amplified
by Q504, this IF signal enters the RF chip (U501), and is mixed with the second local oscillator signal to generate the
second IF signal. The second IF signal is demodulated by U501 to output audio signal, which is sent to MCU for A/D
conversion and filtering. Afterwards, the audio signal is divided into two flows. One flow is processed by CTCSS/CDCSS
decoder; the other is restored to audio signal through filtering, de-emphasis, decoding, signal expansion and D/A
conversion. Then the restored audio signal is amplified by the audio power amplifier (U301) to drive the speaker directly.
Power Supply Section: The 3.7V battery voltage is converted to two flows of 3.0V DC voltage by the LDO module (U602).
One flow supplies 3.0V VCC for the CPU; the other outputs 3.0V V-SAVE voltage, which goes through Q604 and Q601
respectively to supply, under the control TX-CTRL, 3.0V VT for Tx circuit. The V-SAVE voltage also goes through Q602 to
supply 3.0V VR for Rx circuit.

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Signaling Encode: Signaling encode signal output from the port MCU QT_OUT is divided into two flows. One flow goes
through RC network to modulate the PLL reference frequency oscillator; the other goes through QT-MOD to modulate the
VCO.
Battery Charge Section: U604 supplies power to charge battery. Charge indicator glows orange while battery is charging,
and glows green after battery is fully charged. Charge indicator also glows green when there’s no battery.
2. Realization Methods of Basic Functional Modules
2.1 HF Section
2.1.1 Block Diagram of PLL Circuit
QT_OUT
Q103
D105
V_SAVE
Q101 Q102
R103
LD
C132
U501
V_SAVE
D102
R/T
D103
D101
VCO IN
CP
XT101
LOOP FILTER SW
VCO
MOD
RIPPLE FILTER
PLL circuit generates RF carrier signal for Tx and the first local oscillator signal for Rx.
Step frequency of the PLL circuit is 6.25 KHz, 10.0 KHz or 12.5 KHz. In U501, the 21.25MHz reference oscillator signal is
divided into 6.25 KHz, 10.0 KHz or 12.5 KHz reference frequencies via a fixed counter in PLL. The signal output from the
VCO (Tx/RxVCO) enters PLL and is processed by the buffer amplifier. The amplified signal is further processed in PLL by
the variable frequency-divider. Then the signal is compared with the reference frequency in the phase detector (PD) of
PLL. Signal generated from PD passes through a low-pass filter, and then is sent to the varactors (D101 and D102) of
VCO so as to control output frequency. The signal buffer amplified by PLL also serves as the first local oscillator signal for
both Tx and Rx.
The Q103 switch controls connection status of D105 so as to switch between Rx VCO and Tx VCO. When R/T is at high
level, Tx VCO is valid; when R/T is at low level, Rx VCO is valid.
In case pin LD of U501 is at low level, unlock status is valid. When this status is detected by the microprocessor,
transmit/receive operations are prohibited.
2.1.2 Block Diagram of RF Power Amplifier

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W402
ANTENNA
1
V_BAT
R421
R420
R419
VT
Q405
LPFRF AMP
APC
RF AMPPRE AMP
APCSW SW
Q404
TX OUT
U401
Q401 Q402 Q403
The modulated carrier signal output from VCO is pre-amplified by U501, and then goes to the front-stage amplifier Q401,
driver-stage amplifier Q402 and final-stage amplifier Q403 respectively. Afterwards, the amplified RF signal enters the
low-pass filter (LPF) circuit through diode D401, and then is transmitted via the antenna after ultroharmonics are removed.
D402 and D501 compose the Rx-Tx switch circuit.
APC circuit is composed of Q404, Q405 and U401. U401 controls the bias voltage at the gates of Q402 and Q403, to
control Tx current and to further regulate power.
2.1.3 Block Diagram of Rx Circuit
Desired and undesired RF signals received via the antenna are fed to the SAW filter to filter out undesired out-of-band
interference signal. Then the desired RF signal is amplified by Q506 and enters U501, where it is amplified by the
high-frequency low-noise amplifier. Afterwards, the amplified signal goes through the bandpass filter again to filter out
undesired out-of-band interference signal. Desired RF signal is mixed with the first local oscillator signal (output from
VCO) by Q505, to output the first IF signal (21.7MHz), which is processed by the IF filter and IF amplifier Q504.
Afterwards, it is sent to the IF processing circuit of U501.
In U501, this first IF signal is mixed with the second local oscillator signal to generate the second IF signal. Then the

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second IF signal is demodulated by U501 to output audio signal, which is sent to MCU for A/D conversion and filtering.
Afterwards, the audio signal is divided into two flows. One flow is processed by CTCSS/CDCSS decoder; the other is
restored to audio signal through filtering, de-emphasis, decoding, signal expansion and D/A conversion. Then the
restored audio signal is amplified by the audio power amplifier IC (U301) to drive the speaker directly.
2.2 MCU Control, Signal Processing and Audio Power Amplification
Circuit diagram of this section is shown as below:
R602
AMP
R603
SAVE
RESET
B302 Speaker
+
1
-
2
B303
MIC
+
1-
2
ON/OFF
KEY SW UP DOW
AF_OUTP
RFC
APC
QT_OUT
X601
TX_CTL
Q602
U601
D601
LED
1 2
D602
LED
1 2
Q201
Q202
U301
LD
V_BAT
BUSY(SQL)
BAT
DATA
G601
BATTERY
1 2
CK
STB
DEMOD
RESET
APA EN
MIC IN
MOD OUT
R/T
CH SW
VCC
V_SAVE
Q601
VT
U605
VR
J202
EXT PTT
EXT MIC
Q604
J201
U603
SDA
SCL
SW
T_LED
R_LED
EC0
EC1
SW
EC2
EC3
PTT
DC-DC
MON
TXD
RXD
EEPROM
U602
2.2.1 MCU Control Circuit
MCU control circuit is composed of MCU, EEPROM, LCD (exclusive for TC-320), keys, etc. This section has the following
functions: to initialize data of the radio and save data to EEPROM; to drive LCD to display some user set information and
status; to detect battery voltage and signals from external keys, LD and VOX-DET, and to make response; to transmit
required data to PLL based on the channel encoding status; to switch and control Rx/Tx based on the input PTT signal; to
switch the squelch circuit on/off based on the input signaling decode signal and squelch level signal; to control circuits of
high/low power switch, audio power amplifier, VCO power supply, Rx power supply and Tx power supply; (for
programming) to communicate with PC via RXD/TXD based on the RS232 protocol, and transmit/receive data to/from
PC.
2.2.2 Signal Processing Section
2.2.2.1 Tx Baseband Processing
The audio signal input from MIC enters U601, and is then converted into digital signal by analog-to-digital conversion.
Afterwards, the signal is divided by the digital low-pass filter into 2 flows. One flow serves as the signal of VOX detection;
the other is processed by AGC, compandor, high-pass filter, encryption and pre-emphasis, mixed with DTMF signal from
MCU, converted to baseband signal via digital-to-analog conversion to output. Then the signal is processed by the active
low-pass filter, and sent to the VCO for modulation.
2.2.2.2 Rx Baseband Processing
After entering U601, the DEMOD signal derived from IF demodulation is converted to digital signal via analog-to-digital
conversion (ADC), and then is sent to the digital low-pass filter. The signal is divided into 2 flows. One flow is processed
by CTCSS/CDCSS decoder; the other is processed by high-pass filter, and then is subject to de-emphasis, decryption,
signal expansion and DTMF demodulation and etc, and finally digital-to-analog conversion to output audio signal.

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2.2.3 Audio Power Amplifier
The audio signal output from U601 is amplified by the audio power amplifier (U301) to drive the speaker directly.
2.3 Power Supply Processing
Block diagram of power supply circuit is shown as below:
SAVE
Q604
TX_CTL
Q601
G601
BATTERY
1 2
VCC
V_SAVE
Q602
VR
VT
SW
SW
DC-DC
U602
Power Supply Section: The 3.7V battery voltage is converted to two flows of 3.0V DC voltage by U602. One flow supplies
3.0V VCC for the CPU; the other outputs 3.0V V-SAVE, which goes through Q601, Q602 and Q604 respectively to supply,
under the control TX-CTRL, VT for Tx circuit and VR for Rx circuit. U602 also supplies the PLL circuit with voltage
V-SAVE.
CPU Pins
Pin No. Port Pin Name I/O Function
1 None / / /
2 None / / /
3 None / / /
4 None / / /
5 None / / /
6 TXD TXD O UART TxD
7 RXD RXD I UART RxD
8 P60 APA_EN O Control speaker; H: unmute, L: mute
9 P61 SAVE_CTL O Control Power Save; in non-Power-
Save status, it is at high
level.
10 P62 EXT MIC I Check MIC connection (valid for high level)
11 P63 EXT PTT I PTT key on the earpiece (valid for high level)
12 P64 Red LED O Red LED
13 P65 Green LED O Greed LED
14 P66 Reserve O Reserved
15 P67 Reserve O Reserved
16 Vssd GND S Ground power supply for digital circuit

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17 Vddd VCC(3.0V) S Power supply for digital circuit
18 P50/INT0 VOL+ I To increase the volume
19 P51/INT1 VOL- I To decrease the volume
20 P52/INT2 Reserve O Reserved
21 P53/INT3 /POWER
ON/OFF
I Radio On/Off
22 P54/INT4 SK I Programmable function key (side key) (valid for low level),
external pull-up resistor connected
23 P55/INT5 PTT I PTT key (valid for low level), external pull-up resistor
connected
24 P56/INT6 Reserve O Reserved
25 P57/INT7 Reserve O Reserved
26 Vdd_CLD VCC(3.0V) S Power supply for digital PA
27 CLD_OUTP CLD_OUTP O LINEOUT output; positive output of digital PA
28 VSS_CLD GND S Ground power supply for digital PA
29 CLD_OUTM Reserve O Negative output of digital PA
30 Vdd_CLD VCC(3.0V) S Power supply for digital PA
31 P77 RF_CTRL O Control Rx frequency band; high level (high frequency
band); low level (low frequency band)
32 P76/DAC1 APC DA Control transmit power
33 P75/VREF VCC(3.0V) I Input of reference voltage of ADC and DAC
Pin
34 P74/DAC0 QT_OUT DA CTCSS/CDCSS output
35 P73/AD3 Reserve AD Reserved
36 Vssa GND S Ground power supply for analog circuit
37 Vdda VCC(3.0V) S Ground power supply for analog circuit
38 P72/AD2 Reserve AD Reserved
39 P71/AD1 SQL AD Detect noise
40 P70/AD0 BAT_DET AD Detect battery strength
41 XTAL0 OSC0 For 32.678KHz main crystal oscillator
42 XTAL1 OSC1
43 PLL_CAP PLL_CAP For PLL external capacitor (10nF)
44 None / / /
45 None / / /
46 None / / /

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47 None / / /
48 None / / /
49 P03/COM3 Reserve O Reserved
50 P02/COM2 Reserve O Reserved
51 P01/COM1 Reserve O Reserved
52 P00/COM0 Reserve O Reserved
53 P10/SEG0 Reserve O Reserved
54 P11/SEG1 Reserve O Reserved
55 P12/SEG2 Reserve O Reserved
56 P13/SEG3 Reserve O Reserved
57 P14/SEG4 Reserve O Reserved
58 P15/SEG5 Reserve O Reserved
59 P16/SEG6 Reserve O Reserved
60 P17/SEG7 Reserve O Reserved
61 P20/SEG8 EN0 I
To detect input from encoder switch
62 P21/SEG9 EN1 I
63 P22/SEG10 EN2 I
64 P23/SEG11 EN3 I
65 P24/SEG12 Reserve O Reserved
66 P25SEG13 Reserve O Reserved
67 P26/SEG14 Reserve O Reserved
68 P27/SEG15 Reserve O Reserved
69 P30/SEG16 Reserve O Reserved
70 P31/SEG17 Reserve O Reserved
71 None / / /
72 None / / /
73 None / / /
74 None / / /
75 None / / /
76 P32/SEG18 Reserve O Reserved
77 P33/SEG19 Reserve O Reserved
78 P34/SEG20 Reserve O Reserved
79 P35/SEG21 Reserve O Reserved

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80 P36/SEG22 Reserve O Reserved
81 P37/SEG23 Reserve O Reserved
82 P40/SEG24 Reserve O Reserved
83 P41/SEG25 SCL O EEPROM CLOCK, external pull-up resistor connected
84 P42/SEG26 SDA O EEPROM DATA, external pull-up resistor connected
85 P43/SEG27 LD I To detect PLL circuit unlock (H: lock; L: unlock), external
pull-up resistor connected
86 P44/SEG28 DATA O PLL DATA
87 P45/SEG29 CK O PLL CLOCK
88 P46/SEG30 STB O PLL ENABLE
89 Vssd GND S Ground power supply for digital circuit
90 Vddd VCC(3.0V) S Power supply for digital circuit
91 SW_P0 R/T O Rx/Tx control, H: Rx; L: Tx (switch to VCO)
92 SW_P1 TX_CTRL O Control power supply for Tx (transmit at high level)
93 RESET RESET I Reset input
94 Vssa GND S Ground power supply for analog circuit
95 Vdda VCC(3.0V) S Power supply for analog circuit
96 BG_REF O To output reference voltage
97 MIC_IN MIC_IN I Microphone input
98 DEMODE DEMODE I To input baseband signal (audio and CTCSS/CDCSS)
99 MODOUT MODOUT O To output baseband signal (audio and CTCSS/CDCSS)
100 None / / /

TC-320 Service Manual
17
TC-320 Parts List 1
No. Part No. Description Qty. Ref No. Print No.
1 3001050000000 Chip resistor 0402 0ΩJ 1/16W (RoHS) 1 R222 T3G
2 3001050000000 Chip resistor 0402 0ΩJ 1/16W (RoHS) 1 R518 B3H
3 3001050000000 Chip resistor 0402 0ΩJ 1/16W (RoHS) 1 L510 B2H
4 3001050000000 Chip resistor 0402 0ΩJ 1/16W (RoHS) 1 R223 T3G
5 3001050000000 Chip resistor 0402 0ΩJ 1/16W (RoHS) 1 R314 T3B
6 3001050000000 Chip resistor 0402 0ΩJ 1/16W (RoHS) 1 R527 B2H
7 3001051000020 Chip resistor 0402 10ΩF 1/16W (RoHS) 1 R101 B4H
8 3001051000020 Chip resistor 0402 10ΩF 1/16W (RoHS) 1 R119 B3F
9 3001051000020 Chip resistor 0402 10ΩF 1/16W (RoHS) 1 R311 T3A
10 3001051000020 Chip resistor 0402 10ΩF 1/16W (RoHS) 1 R516 B3I
11 3001051000020 Chip resistor 0402 10ΩF 1/16W (RoHS) 1 R530 B2G
12 3001051010040 Chip resistor 0402 100ΩF 1/16W (RoHS) 1 R604 T2E
13 3001051010040 Chip resistor 0402 100ΩF 1/16W (RoHS) 1 R614 T4E
14 3001051010040 Chip resistor 0402 100ΩF 1/16W (RoHS) 1 R621 T4E
15 3001051010040 Chip resistor 0402 100ΩF 1/16W (RoHS) 1 R623 T4E
16 3001051020000 Chip resistor 0402 1KΩF 1/16W (RoHS) 1 R114 B3E
17 3001051020000 Chip resistor 0402 1KΩF 1/16W (RoHS) 1 R207 T2G
18 3001051020000 Chip resistor 0402 1KΩF 1/16W (RoHS) 1 R214 T3D
19 3001051020000 Chip resistor 0402 1KΩF 1/16W (RoHS) 1 R613 T2G
20 3001051020000 Chip resistor 0402 1KΩF 1/16W (RoHS) 1 R109 B4E
21 3001051020000 Chip resistor 0402 1KΩF 1/16W (RoHS) 1 R309 T4D
22 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R107 B4E
23 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R116 B3E
24 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R120 B3F
25 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R210 T5E
26 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R219 T2D
27 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R301 T3A
28 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R409 T2B
29 3001051030000 Chip resistor 0402 10KΩJ 1/16W (RoHS) 1 R428 T2B
30 3001051040000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R213 T3D
31 3001051040000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R113 B3E
32 3001051050000 Chip resistor 0402 1MΩF 1/16W (RoHS) 1 R218 T2D
33 3001051050000 Chip resistor 0402 1MΩF 1/16W (RoHS) 1 R405 T2B
34 3001051220000 Chip resistor 0402 1.2KΩJ 1/16W(RoHS) 1 R220 T4E
35 3001051230000 Chip resistor 0402 12KΩJ 1/16W(RoHS) 1 R224 T3G
36 3001051230000 Chip resistor 0402 12KΩJ 1/16W(RoHS) 1 R528 B2G
37 3001051530000 Chip resistor 0402 15KΩJ 1/16W (RoHS) 1 R406 T2A
38 3001051540000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R422 T3A
39 3001051540000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R423 T3B
40 3001051540000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R424 T3B
41 3001051540000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R425 T3B
42 3001051540000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R426 T3A
43 3001051540000 Chip resistor 0402 100KΩF 1/16W (RoHS) 1 R427 T2A
44 3001052200000 Chip resistor 0402 22ΩJ 1/16W (RoHS) 1 R429 B2F
45 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R202 T2D
46 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R216 T3D
47 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R306 B3H
48 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R407 T2B
49 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R507 B3H
50 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R615 T3H
TC-320U(1) VG Parts List 1 (400-420MHz）

TC-320 Service Manual
18
51 3001052220000 Chip resistor 0402 2.2KΩJ 1/16W (RoHS) 1 R110 B4E
52 3001052230010 Chip resistor 0402 22KΩJ 1/16W (RoHS) 1 R215 T3D
53 3001052230010 Chip resistor 0402 22KΩJ 1/16W (RoHS) 1 R312 B4H
54 3001052240010 Chip resistor 0402 220KΩF 1/16W (RoHS) 1 R602 T2E
55 3001052240010 Chip resistor 0402 220KΩF 1/16W (RoHS) 1 R603 T2E
56 3001052710010 Chip resistor 0402 270ΩJ 1/16W(RoHS) 1 R115 B3E
57 3001052710010 Chip resistor 0402 270ΩJ 1/16W(RoHS) 1 R505 B2I
58 3001052710010 Chip resistor 0402 270ΩJ 1/16W(RoHS) 1 R506 B3H
59 3001052720010 Chip resistor 0402 2.7KΩF 1/16W(RoHS) 1 R502 T3H
60 3001052730010 Chip resistor 0402 27KΩF 1/16W (RoHS) 1 R408 T2A
61 3001052740000 Chip resistor 0402 270KΩJ 1/16W (RoHS) 1 R303 B3H
62 3001053310010 Chip resistor 0402 330ΩJ 1/16W (RoHS) 1 R404 B2E
63 3001053320000 Chip resistor 0402 3.3KΩJ 1/16W (RoHS) 1 R203 T4E
64 3001053320000 Chip resistor 0402 3.3KΩJ 1/16W (RoHS) 1 R204 T4E
65 3001053320000 Chip resistor 0402 3.3KΩJ 1/16W (RoHS) 1 R305 B4H
66 3001053320000 Chip resistor 0402 3.3KΩJ 1/16W (RoHS) 1 R307 B4H
67 3001053320000 Chip resistor 0402 3.3KΩJ 1/16W (RoHS) 1 R401 B2F
68 3001053320000 Chip resistor 0402 3.3KΩJ 1/16W (RoHS) 1 R402 B2E
69 3001053330000 Chip resistor 0402 33KΩF 1/16W(RoHS) 1 R125 B4H
70 3001053920010 Chip resistor 0402 3.9KΩJ 1/16W(RoHS) 1 R606 T4D
71 3001053920010 Chip resistor 0402 3.9KΩJ 1/16W(RoHS) 1 R633 T3G
72 3001053930000 Chip resistor 0402 39KΩJ 1/16W(RoHS) 1 R302 T3A
73 3001054790000 Chip resistor 0402 4.7ΩJ 1/16W(RoHS) 1 R308 T3A
74 3001054790000 Chip resistor 0402 4.7ΩJ 1/16W(RoHS) 1 R310 T3A
75 3001054790000 Chip resistor 0402 4.7ΩJ 1/16W(RoHS) 1 R403 B2E
76 3001054700000 Chip resistor 0402 47ΩJ 1/16W(RoHS) 1 R111 B4E
77 3001054700000 Chip resistor 0402 47ΩJ 1/16W(RoHS) 1 R123 B3F
78 3001054700000 Chip resistor 0402 47ΩJ 1/16W(RoHS) 1 R618 T4G
79 3001054700000 Chip resistor 0402 47ΩJ 1/16W(RoHS) 1 R619 T3G
80 3001054710000 Chip resistor 0402 470ΩJ 1/16W(RoHS) 1 R201 T2D
81 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R112 B3E
82 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R206 T3G
83 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R511 B2H
84 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R512 B1E
85 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R608 T4B
86 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R622 T3D
87 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R117 B3F
88 3001054720000 Chip resistor 0402 4.7KΩJ 1/16W(RoHS) 1 R525 B2G
89 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R103 B4G
90 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R106 B3E
91 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R121 T4F
92 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R205 T4D
93 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R217 T3D
94 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R313 B4H
95 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R610 T4B
96 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R611 T4B
97 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R612 T4B
98 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R616 T4G
99 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R617 T4G
100 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R620 T4B
101 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R624 T4E
102 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R630 T2G
103 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R631 T3H
104 3001054730000 Chip resistor 0402 47KΩJ 1/16W(RoHS) 1 R607 T3G

TC-320 Service Manual
19
105 3001054740000 Chip resistor 0402 470KΩJ 1/16W(RoHS) 1 R212 T5E
106 3001054740000 Chip resistor 0402 470KΩJ 1/16W(RoHS) 1 R517 B3H
107 3001055620000 Chip resistor 0402 5.6KΩJ 1/16W(RoHS) 1 R211 T4E
108 3001055630000 Chip resistor 0402 56KΩJ 1/16W(RoHS) 1 R632 T3G
109 3001056820000 Chip resistor 0402 6.8KΩJ 1/16W(RoHS) 1 R208 T4D
110 3001056820000 Chip resistor 0402 6.8KΩJ 1/16W(RoHS) 1 R529 B2G
111 3001056830000 Chip resistor 0402 68KΩJ 1/16W(RoHS) 1 R102 B4H
112 3001056830000 Chip resistor 0402 68KΩJ 1/16W(RoHS) 1 R124 B4F
113 3001056830000 Chip resistor 0402 68KΩJ 1/16W(RoHS) 1 R304 B4H
114 3001056840000 Chip resistor 0402 680KΩJ 1/16W(RoHS) 1 R501 B3H
115 3001057520000 Chip resistor 0402 7.5KΩJ 1/16W(RoHS) 1 R118 B3E
116 3001058200000 Chip resistor 0402 82ΩF 1/16W(RoHS) 1 R526 B3G
117 3001058220000 Chip resistor 0402 8.2KΩJ 1/16W(RoHS) 1 R209 B3F
118 3001058220000 Chip resistor 0402 8.2KΩJ 1/16W(RoHS) 1 R606 T4C
119 3001060000000 Chip resistor 0603 0ΩJ 1/10W(RoHS) 1 L105 B3F
120 3001061010000 Chip resistor 0603 100ΩJ 1/10W(RoHS) 1 R418 T2B
121 3001061010000 Chip resistor 0603 100ΩJ 1/10W(RoHS) 1 R605 T3A
122 3001062230000 Chip resistor 0603 22KΩJ 1/10W(RoHS) 1 R411 B2D
123 3001062230000 Chip resistor 0603 22KΩJ 1/10W(RoHS) 1 R412 B2D
124 3001062230000 Chip resistor 0603 22KΩJ 1/10W(RoHS) 1 R416 B2D
125 3001062230000 Chip resistor 0603 22KΩJ 1/10W(RoHS) 1 R417 B2C
127 3001064700000 Chip resistor 0603 47ΩJ 1/10W(RoHS) 1 R410 B2D
128 3001064700000 Chip resistor 0603 47ΩJ 1/10W(RoHS) 1 R415 B3C
129 3001064710000 Chip resistor 0603 470ΩJ 1/10W(RoHS) 1 R634 B5A
130 3001064710000 Chip resistor 0603 470ΩJ 1/10W(RoHS) 1 R609 B5A
131 3001066810010 Chip resistor 0603 680ΩJ 1/10W(RoHS) 1 R625 T4A
132 3099080398000 Chip resistor 1206 0.39ΩJ 1/4W(RoHS) 1 R419 T3B
133 3099080398000 Chip resistor 1206 0.39ΩJ 1/4W(RoHS) 1 R420 T3B
134 3099080398000 Chip resistor 1206 0.39ΩJ 1/4W(RoHS) 1 R421 T3B
135 3005051020010 Resistor array 0402 1K*4 J 1/16W(RoHS) 1 RN101 T4F
136 3002991030150 Adjustable resistor(2.7*2.0*0.9) 10KΩ±30%(RoHS) 1 VR101 B4H
137 3002991030150 Adjustable resistor(2.7*2.0*0.9) 10KΩ±30%(RoHS) 1 VR601 T3G
138 3101050390000 Chip capacitor 0402 0.3PF B 50V Hi-Q (RoHS) 1 C534 B3H
139 3101050590010 Chip capacitor 0402 0.5PF B 50V Hi-Q(RoHS) 1 C109 B3E
140 3101050590010 Chip capacitor 0402 0.5PF B 50V Hi-Q(RoHS) 1 C144 B3F
141 3101050100010 Chip capacitor 0402 1PF B 50V Hi-Q(RoHS) 1 C527 T2H
142 3101051590000 Chip capacitor 0402 1.5PF B 50(RoHS) 1 C431 B3A
143 3101050200010 Chip capacitor 0402 2PF B 50V(RoHS) 1 C428 B3A
144 3101050200010 Chip capacitor 0402 2PF B 50V(RoHS) 1 C433 B3A
145 3101050200010 Chip capacitor 0402 2PF B 50V(RoHS) 1 C401 B2F
146 3101050800000 Chip capacitor 0402 8PF B 50V (RoHS) 1 C149 B4F
147 3199052290000 Chip capacitor 0402 2.2PF B 50V Hi-Q(RoHS) 1 C110 B3E
148 3101050300000 Chip capacitor 0402 3PF B 50V(RoHS) 1 C130 B3E
149 3101050300000 Chip capacitor 0402 3PF B 50V(RoHS) 1 C501 B2B
150 3101050300000 Chip capacitor 0402 3PF B 50V(RoHS) 1 C545 B3H
151 3101053690000 Chip capacitor 0402 3.6PF B 50V (RoHS) 1 C432 B3A
152 3101050400010 Chip capacitor 0402 4PF B 50V(RoHS) 1 C502 B2B
153 3101050400010 Chip capacitor 0402 4PF B 50V(RoHS) 1 C421 B3B
154 3199054790000 Chip capacitor 0402 4.7PF C 50V(RoHS) 1 C430 B3A
155 3101050500000 Chip capacitor 0402 5PF D 50V(RoHS) 1 C434 B3A
156 3101050600010 Chip capacitor 0402 6PF B 50V(RoHS) 1 C406 B2F
157 3101050600010 Chip capacitor 0402 6PF B 50V(RoHS) 1 C439 B2F
158 3101050600010 Chip capacitor 0402 6PF B 50V(RoHS) 1 C148 B3E
159 3101050900000 Chip capacitor 0402 9PF B 50V (RoHS) 1 C112 B3F