HYT tc-600 User manual

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Contents
General………………………………………………………………………………2
Brief Introduction………………………………………………………………….3
Software Specification……………………………………………………………5
Circuit Description……………………………………………………………….11
CPU Pins…………………………………………………………………………...16
TC-600U Part List 1…………………...………………………………………….18
TC-600V Part List 1…………………...………………………………………….30
Adjustment Description…………………………………………………………42
Disassembly and Assembly for Repair……………………………………….45
Exploded View…………………………………………………………………….48
Part List 2…………………………………………………………………………49
Packing…………………………………………………………………………….51
PC Board View……………………………………………………………………52
Block Diagram…………………………………………………………………….56
Schematic Diagram………………………………………………………………57
Specifications…………………………………………………………………….59

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General
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.
User Safety Information
The following precautions are recommended for personnel safety:
DO NOT transmit until all RF connectors are verified secure and any open connectors are properly
terminated.
SHUT OFF and do not operate this equipment near electrical blasting caps or in an explosive
atmosphere.
When in vehicles with an airbag, do not place a portable radio in the area over an airbag or in the
airbag deployment area.
Do not expose the radio to direct sunlight for a long time nor place it close to a heating source.
Do not use any portable radio with a damaged antenna. If a damaged antenna comes into contact
with your skin, a minor burn may result.
When transmitting with a portable radio, hold the radio in a vertical position with its microphone
about 5 centimeters away from your mouth.
If you wear a portable radio on your body, be sure to keep the antenna at least 2.5
centimeters away from your head or body when transmitting.
This equipment should be serviced by qualified technicians only.

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Brief Introduction
1. Antenna
Used to transmit/receive signals.
2. LED Indicator
The light will glow red during transmission and glow green during receiving. During transmission,
the light flashes red when the battery voltage is low.
3. Channel Selector Knob
4. Power/Volume Control Knob
Rotate the Power/Volume Knob clockwise until a “click” is heard to turn the radio on, fully counter
clockwise until a “click” is heard to turn the radio off. When the radio is on, turn the knob to adjust
volume.
5. PTT Key
Press and hold PTT key to talk, release to receive.
6. Function Key
The key can be programmed to access the radio features with the preset type of key pressing
through the programming software.
7. Microphone
Used to input sounds.
8. Speaker
Used to output sounds.

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9. External Jack (for external earphone or radio programming)
Rotate the jack cover and insert accessory plug, or insert programming cable into the jack to
program the radio via programming software.
10. Battery
11. Belt Clip
Used to clip radio on your belt.
12. Battery Latch
Used to fasten and remove the battery.
13. Charging Connector
Insert the battery into the charger; connect the charging connectors with those on the charger to
begin charging.

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Software Specification
Radio Feature Description
1. Use Channel Selector Knob to choose from 15+1(Scan) channels
2. Monitor
3. CTCSS/CDCSS Encode & Decode
CTCSS: 38 groups
CDCSS: 83 groups
4. Wideband (25KHz) / Narrowband (12.5KHz)
5. Channel Scan (Priority channel and Revert channel available)
6. Battery Save feature (Dealer programmable)
7. Time-out Timer (TOT)
8. Squelch Level (0-9)
9. Low Battery Alert
10. Programmable Function Key
11. High/Low Power
12. 2-Tone Encode & Decode
13. DTMF ANI
14. Model Set Mode
15. PC Programming & Adjust Mode
16. Manual Adjust Mode
17. User Wired Clone Mode
18. Factory Wired Clone Mode

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Radio Modes
Mode Entry for Mode Startup Audible & Visual Indicator
User Mode Disconnect the SELF points and then turn the
power on Power-on alert tone (one long Beep)
Model Set Mode Short out the SELF points and then turn the power
on
2 short Beeps, the light flashes from red
to green
User Wired Clone Mode
Disconnect the SELF points, turn on the power
while holding down Function Key, press Function
Key again
1 short Beep
Factory Wired Clone
Mode
Short out the SELF points, turn on the power while
holding down Function Key, press Function Key
again
2 short Beeps
Manual Adjust Mode
Enable Manual Adjust Mode, turn on the power
while holding down [PTT] and Function Key
simultaneously, the radio enters this mode in 2
seconds
2 short Beeps, orange light glows
PC Programming &
Adjust Mode
Connect the radio with PC, turn on the radio and
activate this mode in programming software
1. User Mode
User Mode is for conventional communication operation. Disconnect the two SELF points and then turn
the power on, the radio enters User Mode. (Refer to “TC-600 Owner’s Manual” for detailed operation
description.)
2. Model Set Mode
(1) Select MS1 according to the radio model. If MS1 is 1, short out the two MS1 points on PCB. If not,
disconnect the two MS1 points.
(2) Short out the two SELF points and then turn the power on. Two Beeps sound.
(3) Turn Channel Selector Knob to the corresponding position (1-11) according to the radio model
(Refer to “Initial Data Table”).
(4) Press [PTT] while holding down Function Key to set the model. Channel data and settings are
initialized (Refer to “Initial Data Table”).

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(5) Turn off the power and then disconnect the two SELF points to complete the model setting.
For example, MS1 of TC-600U (450.000~469.995MHz) is 0 and its model is 7(Refer to “Initial
Data Table”). To initialize its model and channel data, you can operate as following:
● Disconnect the two MS1 points.
● Short out the two SELF points.
● Turn on the power and rotate the Channel Selector Knob to CH7.
● Press [PTT] while holding down Function Key.
● After reset, turn off the power and disconnect the two SELF points. The radio operates at the
preset frequency after restart.
Note: Once the new model is set, previous channel settings (frequency, CTCSS/CDCSS, channel
function settings) will be deleted, and part of functions are also changed. Therefore, do not make this
operation unless it’s very necessary, such as changing the EEPROM, etc.
3. PC Programming Mode
The following parameters can be set through programming software:
(1) Receive frequency and transmit frequency
(2) Receive signaling and transmit signaling
(3) Busy channel lockout (BCL)
(4) Time-out timer (TOT)
(5) Squelch level
(6) Battery save
(7) Audio alarm
(8) Monitor mode
(9) Scan mode
(10) Scan revert channel
(11) Priority scan channel
(12) Wideband/narrowband per radio
(13) High/low power
(14) Wideband/narrowband per channel

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4. PC Adjust Mode
The following settings can be adjusted through the programming software:
(1) Low battery alert level
(2) SQL9
(3) SQL3
(4) CTCSS deviation (wide)
(5) CDCSS deviation (wide)
(6) CTCSS deviation (narrow)
(7) CDCSS deviation (narrow)
5. Manual Adjust Mode
If Manual Adjust Mode is enabled, turn on the power while holding down [PTT] and Function Key
simultaneously, the radio enters Manual Adjust Mode in 2 seconds. Choose the adjusting items by
turning the channel selector knob to CH1-CH7; use [PTT] /Function Key to adjust upwards/downwards
(Note: MIC jack shouldn’t be connected with external cable while adjusting), CH1-CH7 are defined as
follows:
(1) Low battery alert level
(2) SQL9
(3) SQL3
(4) CTCSS deviation (wide)
(5) CDCSS deviation (wide)
(6) CTCSS deviation (narrow)
(7) CDCSS deviation (narrow)

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CH12-CH16 are used to adjust transmitter and receiver. Press [PTT] to transmit; release to receive. In
receive mode, short press the Function Key to toggle among high and low power, or long press it to
switch between wideband and narrowband. Three Beeps alternating from high tone to low tone indicate
that the transmit power is switched from high to low; and three beeps alternating from low tone to high
tone indicate that the transmit power is switched from low to high. Two Beeps sound when wideband is
selected and one Beep sounds when narrowband is selected. CH12-ch16 are defined as follows:
(12) Center frequency (the difference between RX and TX frequency is 0.1MHz)
(13) Lowest frequency (the difference between RX and TX frequency is 0.1MHz)
(14) Highest frequency (the difference between RX and TX frequency is –0.075MHz)
(15) Center frequency: transmit DTMF number “9” (the difference between RX and TX frequency is
0.1MHz)
(16) Center frequency: transmit with 250.3Hz CTCSS signaling (the difference between RX and TX
frequency is 0.1MHz)
Note:
To enable/disable the Manual Adjust Mode: short out the two SELF points, turn on the power to enter
Model Set Mode, then Manual Adjust Mode is enabled. Press [PTT] to disable. It suggests this mode be
disabled after the adjustment is completed.
6. User/Factory Wired Clone Mode
The only difference between the two modes is that the latter is able to clone the adjustment settings.
Turn on the power while holding down Function key to enter Wired Clone Mode.
a) If the two SELF points are disconnected, press Function key again, the radio starts user wired clone
and red LED flashes; when cloning is completed, red LED goes out.
b) If the two SELF points are short out, press Function key again, the radio starts factory wired clone
and red LED flashes; when cloning is completed, red LED goes out.

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Initial Data Table
MS1 Model
Frequency
(MHz)
IF
(MHz)
1CH (Center) 2CH (Low) 3CH (High) 4CH 5CH 6CH 7CH 8CH 9-16CH
Tx
(MHz)
Rx
(MHz)
Tx
(MHz)
Rx
(MHz)
Tx
(MHz)
Rx
(MHz) (MHz) (MHz) (MHz) (MHz) (MHz) (MHz)
0 1 150.000~173.995 +45.050 162.000 162.100 150.000 150.100 173.975 173.900 162.500 162.550 162.600 162.550 162.650
0 2 136.000~149.995 +45.050 143.000 143.100 136.000 136.100 149.975 149.900 143.500 143.550 143.600 143.550 143.650
0 3 146.000~173.995 +45.050 160.000 160.100 146.000 146.100 173.975 173.900 160.500 160.550 160.600 160.550 160.650
0 4 144.000~147.995 +45.050 146.000 146.100 144.000 144.100 147.975 147.900 146.500 146.550 146.600 146.550 146.650
0 5 136.000~147.995 +45.050 142.000 142.100 136.000 136.100 147.975 147.900 142.500 142.550 142.600 142.550 142.650
0 6 136.000~173.995 +45.050 155.000 155.100 136.000 136.100 173.975 173.900 155.500 155.550 155.600 155.550 155.650
0 7 450.000~469.995 -45.050 460.000 460.100 450.000 450.100 469.975 469.900 460.300 460.350 460.400 460.350 460.450
0 8 400.000~419.995 -45.050 410.000 410.100 400.000 400.100 419.975 419.900 410.500 410.550 410.600 410.550 410.650
0 9 470.000~489.995 -45.050 480.000 480.100 470.000 470.100 489.975 489.900 480.500 480.550 480.600 480.550 480.650
0 10 490.000~511.995 -45.050 501.000 501.100 490.000 490.100 511.975 511.900 501.500 501.550 501.600 501.550 501.650
0 11 220.000~239.995 -45.050 230.000 230.100 220.000 220.100 239.975 239.900 230.500 230.550 230.600 230.550 230.650
1 1 240.000~259.995 -45.050 250.000 250.100 240.000 240.100 259.975 259.900 250.500 250.550 250.600 250.550 250.650
1 2 336.000~367.995 -45.050 352.000 352.100 336.000 336.100 367.975 367.900 352.500 352.550 352.600 352.550 352.650
1 3 368.000~395.995 -45.050 382.000 382.100 368.000 368.100 395.975 395.900 382.500 382.550 382.600 382.550 382.650
1 4 370.000~389.995 -45.050 380.000 380.100 370.000 370.100 389.975 389.900 380.500 380.550 380.600 380.550 380.650
1 5 350.000~369.995 -45.050 360.000 360.100 350.000 350.100 369.975 369.900 360.500 360.550 360.600 360.550 360.650
1 6 406.000~429.995 -45.050 418.000 418.100 406.000 406.100 429.975 429.900 418.500 418.550 418.600 418.550 418.650
1 7 400.000~429.995 -45.050 415.000 415.100 400.000 400.100 429.975 429.900 415.500 415.550 415.600 415.550 415.650
1 8 430.000~439.995 -45.050 435.000 435.100 430.000 430.100 439.975 439.900 435.500 435.550 435.600 435.550 435.650
1 9 438.000~449.995 -45.050 444.000 444.100 438.000 438.100 449.975 449.900 444.500 444.550 444.600 444.550 444.650
1 10 480.000~519.995 -45.050 500.000 500.100 480.000 480.100 519.975 519.900 500.500 500.550 500.600 500.550 500.650
1 11 441.000~451.000 -45.050 446.000 446.100 441.000 441.100 450.975 450.900 446.500 446.550 446.600 446.550 446.650
CH QT/DQT OFF OFF OFF OFF OFF OFF OFF 023 023 127.3 151.4

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Circuit Description
1. Frequency Configuration
The receiver utilizes double conversion superheterodyne. The first IF is 45.050MHz and the second
is 455 KHz. The first local oscillator signal is supplied from PLL circuit. Frequency needed in the
transmitter is supplied from PLL circuit. Figure 1 shows the frequency configuration.
Frequency Range: 400 MHz—420MHz 450 MHz—470MHz
136 MHz—150MHz 150 MHz—174MHz
Figure 1 Frequency Configuration
2. Receiver
The receiver utilizes double conversion superheterodyne.
1) Front-End RF Amplifier
The input signal from antenna is amplified in RF amplifier (Q27) after passing through the
receive/transmit switch circuit and a 3-stage LC band pass filter. The amplified signals are
filtered by a band pass filter (a 3-stage LC BPF) to eliminate unwanted signals before they
goes to the first mixer.
MCF
45.050MHz
44.595MHz

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Figure 2 Receiver Section Configuration
2) The First Mixer
The signal from RF amplifier is mixed with the first local oscillator signal from PLL frequency
synthesizer in the first mixer (Q23) to generate a 45.050MHz first IF signal. The first IF signal is then
fed through two monolithic crystal filters (XF1) to remove spurious signals from adjacent channels.
3) IF Amplifier
The first IF signal is amplified in Q22 and then enters the IF processing chip IC1. The signal is mixed
with the second local oscillator signal in IC1 to create a 455KHz second IF signal. The second IF
signal is then fed to a 455KHz ceramics filter (CF1) to eliminate unwanted signals before it is amplified
and detected in IC1.
4) AF Amplifier
The demodulated AF signal obtained from IC1 is amplified in IC7 (1/4), and then filtered by low pass
filter Q19 and high pass filter Q20, and then de-emphasized by R130 and C156. The resulting AF
signal passes through a volume control circuit and then is amplified to a sufficient level to drive the
speaker by AF power amplifier (IC8).
5) Squelch
Part of the AF signal from IC1 reenters IC1, and the noise component is amplified and rectified by a
filter and an amplifier to produce a DC voltage corresponding to the noise level. The DC signal goes to
the analog port of the microprocessor (IC11). IC11 determines whether to output sounds from the
speaker by detecting whether the input voltage is higher or lower than the preset value.
To output sounds from the speaker, IC11 sends a high level signal to the MUTE and AFCO lines and
turns on IC8 through Q12.

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DET
FM IF IC1
IF AMP
HPF
AMP
IC7
AF LPF HPF
DET
239 40 1
SW
Q12
SW
AF/PF AMP
IC7
LPF
IC11
MCU
BUSY
MUTE
AFCO
TI
IC8
SP
Figure 3. AF Amplifier and Squelch Circuit
6) Receive Signaling
CTCSS/CDCSS
Over 300Hz audio frequencies of the signal output from IC1 is cut off by a low pass filter. The resulting
signal enters the microprocessor IC11. IC11 determines whether the CTCSS/CDCSS matches the
preset value, and controls the MUTE, AFCO and the speaker output according to the squelch results.
2-Tone
The output 2-Tone signal from IC1 goes to IC7 (1/4) for voltage amplification, then is processed by
shaping circuit that is comprised of IC7 (2/4) and other components before being detected by IC11 Pin11.
IC11 determines whether the 2-tone matches the preset value, and controls MUTE, APCO and speaker
output according to squelch results.
3. PLL Frequency Synthesizer
PLL circuit generates the first local oscillator signal for reception and the RF signal for transmission.
1) PLL
The step frequency of PLL circuit is 5KHz\6.25KHz\12.5 KHz\10 KHz. A 12.8MHz reference
oscillator signal is divided at IC2 by a fixed counter to produce a 5 KHz\6.25KHz\12.5 KHz\10
KHz reference frequency. The output signal from voltage control oscillator (VCO) passes
through buffer amplifier Q14 and is divided at IC2 by the programmable dual-module counter.
The divided signal is compared in the phase comparator IC2 with the 5 KHz\6.25KHz\12.5 KHz\25
KHz reference signal. The output signal from phase comparator is filtered by a low-pass filter
and passed to the VCO to control the oscillator frequency. (See Figure 4)

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Figure 4 PLL Circuit
2) VCO
The operation frequency is generated by Q16 in transmit mode and by Q8 in receive mode.
The operation frequency generates a control voltage through the phase comparator to control
the varactor diodes, so that the oscillator frequency is made consistent with the preset
frequency in CPU (D2 and D3 in transmit mode, D7 and D8 in receive mode). In receive mode,
Q6 turns off Q16 and turns Q7 on, which causes the T/R pin to be set high. The T/R pin is set low in
transmit mode. The output from Q8 and Q16 is amplified by Q14 and sent to the buffer amplifier.
4. Transmitter
1) Transmit Audio
The modulation signal from microphone is amplified by IC3, pre-emphasized, then filtered by another
low pass filter （ separate filter ） (Q25 and Q24) to eliminate the frequencies higher than 3KHz. The
resulting signal enters the VCO for direct FM modulation. The voice voltage amplitude control circuit
（ Q46\R131\R601 ） is used to switch between wideband and narrowband. (See Figure 5)
2) CTCSS/CDCSS Encoder
The signal needed by CTCSS/CDCSS encoder is generated by IC11 and FM-modulated to the PLL
reference signal. Since the reference OSC does not modulate the loop characteristic frequency or
higher, modulation is performed at the VCO side by splitter. (See Figure 5)
Figure 5 Transmit CTCSS

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3) DTMF/2-Tone Encoder
DTMF/2-Tone signalings are generated by IC11 and outputted in parallel by Pin 48-51. The output signal
is reshaped by resistor array CP7-CP10, then sent to IC3 (1/4) for amplification, and filtered by active
LPF consisting of Q25, Q24 and other components to eliminate the corresponding HF emission before
being passed to TX VCO for modulation. The modulated signal is applied to AF AMP through C254 for
ease of monitoring.
4) RF Amplifier
The transmit signal obtained from VCO buffer amplifier Q14 is amplified by Q15 and Q17. The amplified
signal is passed to power amplifier Q32 and Q31, and is capable of generating a 4.0W RF power. Q50
and R617 are used to toggle between high and low power.
5) Antenna Switch and LPF
The output signal from RF amplifier is passed through a low-pass filter network and a transmit/receive
switch circuit before reaching the antenna terminal. The transmit/receive switch circuit is comprised of
D11 and D12. D11 and D12 is turned on (conductive) in transmit mode and off (isolated) in receive
mode.
5. Power
The 5V reference power supply for the control circuit is derived from a LDO IC. The reference power
provides a 5V voltage in transmit mode [T_V], a 5V voltage in receive mode [R_V], and a 5V voltage
shared in both modes based on the control signal from the microprocessor.
6. Control System
The IC11 CPU operates at 7.3728MHz.