HYT TC-700P User manual

TC-700P Service Manual
1
Contents
Revision History------------------------------------------------------------------------------------------------------------2
Introduction------------------------------------------------------------------------------------------------------------------2
Safety Information--------------------------------------------------------------------------------------------------------2
Radio Overview-------------------------------------------------------------------------------------------------------------3
Software Specifications -------------------------------------------------------------------------------------------------4
Circuit Description---------------------------------------------------------------------------------------------------------7
CPU Pins---------------------------------------------------------------------------------------------------------------14
TC-700P VHF Parts List 1-------------------------------------------------------------------------------------------------19
TC-700P UHF Parts List 1-------------------------------------------------------------------------------------------------42
Tuning Description------------------------------------------------------------------------------------------------63
Troubleshooting Flow Chart---------------------------------------------------------------------------------------------72
Disassembly and Assembly for Repair---------------------------------------------------------------------------76
Exploded View------------------------------------------------------------------------------------------------------------79
TC-700P Parts List 2--------------------------------------------------------------------------------------------------80
Packing----------------------------------------------------------------------------------------------------------------------81
TC-700P VHF PCB View----------------------------------------------------------------------------------------------------82
TC-700P UHF PCB View----------------------------------------------------------------------------------------------------84
TC-700P Block Diagram----------------------------------------------------------------------------------------------------86
TC-700P VHF Schematic Diagram--------------------------------------------------------------------------------------87
TC-700P UHF Schematic Diagram--------------------------------------------------------------------------------------93
Specifications------------------------------------------------------------------------------------------------------------------99

TC-700P Service Manual
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Revision History
Material No. Date of Issue Changes
Initial Release
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
The following safety precautions shall always be observed during operation, service and repair of this
equipment.
◇ This radio shall be serviced by qualified technicians only.
◇ Only use Hytera 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.
◇ During transmission, hold the radio in a vertical position with its microphone 2.5 to 5.0
centimeters (1-2 inches) away from your lips, and keep the antenna at least 2.5 centimeters
(approximately 1 inch) away from your head. If you wear a portable radio on your body, ensure
that the antenna is at least 2.5 centimeters (approximately 1 inch) away from your body when
transmitting.

TC-700P Service Manual
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Radio Overview
(1) PTT (Push-to-Talk) Key (2) SK1 (3) SK2 (4) Antenna
(5) Speaker (6) Microphone (7) TK (8) Channel
Selector Knob
(9) Radio On-Off/Volume
Control Knob (10) LED Indicator (11) Battery Latch (12) Belt Clip
(13) Accessory Jack (14) Battery (15) Charging Piece

TC-700P Service Manual
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Software Specifications
Status Indications
Operation/Function LED Indication and Alert Tone
To enter Wired Clone mode:
For the source radio, turn it on while holding down
PTT and SK2.
For the target radio, turn it on directly.
The LED on the source radio
flashes red once upon power-on.
Status of the source radio in Wired Clone mode
(After the target radio is turned on and the cloning
cable is connected, press PTT of the source radio
to begin cloning.)
The LED glows red during
cloning.
The LED goes out if cloning is
completed successfully.
The LED flashes orange if
cloning fails.
Wired
Clone
Mode
Status of the target radio in Wired Clone mode The LED glows green during
cloning.
The LED goes out if cloning is
completed.
To enter Wireless Clone mode:
In Wired Clone mode, press SK2 of the source
radio and target radio respectively to switch to
Wireless Clone mode.
The LED on the source radio
and the target radio flashes
green once respectively.
Wireless
Clone
Mode
Status of the source radio in Wireless Clone mode
(After the source radio and target radio are powered
on properly and are operating on the same channel,
press PTT of the source radio to start cloning.)
The LED glows red during
cloning.
The LED glows orange if cloning
is completed.

TC-700P Service Manual
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Status of the target radio in Wireless Clone mode The LED glows green during
cloning.
The LED glows orange if cloning
is completed successfully.
The LED flashes orange if
cloning fails.
Power-on (to enter User Mode) The LED flashes green once.
Low battery alert The LED flashes red, and three
beeps sound every 30 seconds.
Transmitting The LED glows red.
Receiving The LED glows green.
Scanning The LED flashes green.
Writing/Reading The LED glows red during
reading.
The LED glows green during
writing.
Encode (DTMF/PTT ID/2-Tone/5-Tone/HDC1200/HDC2400TM)The LED glows red during
encoding.
The LED glows orange after
encoding.
Decode (2-Tone/5-Tone/HDC1200/HDC2400TM)The LED flashes orange after
decoding.
Selecting a power level 1W: one beep sounds.
2W: two beeps sound.
5W: three beeps sound.
Pressing a programmable key Enable a function: one beep
sounds.
Disable a function: two beeps
sound.

Remark : scrambler option has been removed for Egypt.
5. PC Mode
adio manually or automatically via a PC.
TC-700P Service Manual
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Description of Modes
1. User Mode
It is the conventional communication mode.
2. All Reset Mode
In this mode, the tuning values, channel frequencies and function data will be initialized. Please refer to
the section “Tuning Description” for details.
3. Clone Mode
Wired Clone Mode (Factory)
Wired Clone Mode (Dealer)
Wireless Clone Mode (Factory)
Wireless Clone Mode (Dealer)
Power on the radio while holding down PTT and SK2 to enter Wired Clone mode.
Press SK2 to switch between Wired Clone mode and Wireless Clone mode.
Press TK to switch between Factory mode and Dealer mode.
4. Manual Tuning Mode
In this mode, you can manually adjust frequency deviation, power level, sensitivity, squelch level and etc.
Note: You can enter this mode only after the Manual Tuning mode is selected via the programming
software. Please refer to the section “Tuning Description” for details.
In this mode, you can adjust your r

TC-700P Service Manual
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Circuit Description
1. Circuit Composition
The general circuit is composed of PLL-VCO, TX circuit, RX circuit, baseband processing circuit, power
supply circuit, MCU control circuit and etc.
2. Power Supply
TC-700P adopts the "soft power-down” feature. The battery supplies voltage B+ via the 3A fuse to
TC-700P radio. U601 supplies power to the motor via Q601; U602 supplies 5V (M5V) voltage to the
control circuit; U604 supplies 5V (C5V) voltage to the common circuit; U603 supplies T5V, R5V, 5CNS
voltage. During transmitting, T5C turns to high voltage, and Q607 is turned on to supply 5V (T5V)
voltage to the TX circuit. During receiving, R5C turns to high voltage, and Q606 is turned on to supply 5V
(R5V) voltage to the RX circuit.
3V AVR
U601
SW
FUSE
M5V
SAVE
MOTOR_CON
MOTOR
T5C
R5C
5CNS
T5V
R5V
C5V
Q601
2SA1745
B+
B+
Q602
DTC144EE
5V AVR
U602
5V AVR
U603
5V AVR
U604
Q606
2SA1745
Q607
2SA1745
Q603
2SA1745
SWB+
D613 Q604
2SK1824
SBC
Q605
2SK1824
PWS
Figure 1 Diagram of Power Supply Circuit
3. PLL Frequency Synthesizer
The PLL circuit provides the first local oscillator (LO) signal for receiving and RF carrier signal for
transmitting.

TC-700P Service Manual
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Figure 2 Diagram of PLL Circuit
(1) PLL Circuit
The PLL circuit adopts the second harmonic. The step frequencies available for the circuit are 2.5KHz,
5.0KHz or 6.25KHz. In U101, the 16.8MHz reference oscillator signal is divided into 2.5KHZ, 5.0KHz or
6.25KHz reference frequencies via a counter. The signal from the VCO goes through the buffer amplifier
Q107, and goes to U101, where it is divided by a frequency divider. Then the signal is compared with the
2.5KHz/5.0KHz/6.25KHz reference signal in a phase detector U101. After comparison, the signal goes
through a low-pass filter, and a DC level is generated. This level controls the VCO so as to control its
oscillation frequency.
(2) VCO
The operating frequency is generated via Q103 in TX mode and via Q101 in RX mode. The frequency
generates a control voltage via the phase detector to control the varactors (D105, D106, and D107 in TX
mode; D101, D102, D103 and D104 in RX mode) to make the oscillation frequency consistent with the
preset frequency of MCU. In RX mode, T/R is set to high level. In TX mode, T/R is set to low level. The
output from Q103 and Q101 is amplified by Q106 and then sent to the buffer amplifier.
(3) Unlock Detector
If the MUXOUT pin of U101 is at low level, unlock status occurs. If the microprocessor detects such
situation, TX operation is prohibited.
4. RX Circuit
The RX circuit utilizes double conversion superheterodyne techniques. The first IF is 44.85MHz and the
second IF is 455KHz. The first LO signal is supplied by the PLL & VCO circuit, and the second LO signal
is generated by the 44.395MHz crystal.

TC-700P Service Manual
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Figure 3 Diagram of RX Circuit
(1) RF AMP & BPF
After passing through the TX-RX switch circuit and bandpass filter (BPF) circuit, signals received by the
antenna are amplified by the RF amplifier (Q410). Then the amplified signals feed to the bandpass filter
to remove unwanted signals, allowing wanted signals to go to the first mixer only.
(2) The First Mixer
The signals output by RF AMP&BPF are mixed with the first LO signal output by the PLL frequency
synthesizer at the first mixer (Q415) to generate a 44.85MHz first IF signal, which will feed to a crystal
filter (XF401) to further remove spurious signals.
(3) IF Amplifier
After amplified at Q412, the first IF signal enters U403 (TA31136FN), where it is mixed with the second
LO signal (44.395MHz) to generate a 450KHz second IF signal. Then the second IF signal feeds to a
pair of ceramic filters (N: Z403; W: Z404), where unwanted signals are removed. Finally the signal
passes through the frequency discriminating circuit of U403 and is output as audio signal from Pin 9.
(4) Wide/Narrow Band Switch Circuit
When the WCON pin of U605 is at high level, the diode circuit is turned on, and the ceramic filter Z404
(W) is operating to remove unwanted signals. When the NCON pin of U605 is at high level, the diode
circuit is turned on, and the ceramic filter Z403 (N) is operating to remove unwanted signals.
(5) Audio Amplifier Circuit
After amplifier at U201, the audio signal output by U403 enters U203 for audio processing (the received
signaling is derived for decoding). Then the signal passes through AF_MUTE, SW601 (volume control),
Q615 (PA_MUTE). Finally the signal goes to the audio amplifier (U609) and is output to the speaker as

TC-700P Service Manual
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audio signal.
(6) Squelch Control Circuit
Noise signal is derived from the audio signal output by Pin 9 of U403, and is processed by U403 to
produce a SQL level. Then the SQL level feeds to CPU (U605), and is compared with the preset level to
generate a level which controls AF_MUTE and PA_MUTE. The level controls Q204 and Q615 to
determine whether to output audio from the speaker.
5. TX Circuit
The transmitter circuit consists of MIC circuit, frequency synthesizer circuit, RF driver and final-stage
amplifier circuit and APC circuit.
Figure 4 Diagram of Transmitter Circuit
（1） MIC Circuit and Modulation Circuit
The audio signal from MIC passes through the MIC control switch (Q616), and goes to U204 for
amplification. Then the amplified signal goes to U203 for further amplification, pre-emphasis and other
audio processing. Meanwhile, DTMF/2-Tone/5-Tone signaling generated by MCU also goes to U203 for
amplification, and then is mixed with the audio signal. After mixing, the audio signal and the
DTMF/2-Tone/5-Tone signaling feed to the VCO for modulation.
（2） RF Driver and Final-stage Amplifier Circuit
The RF signal from the LO circuit is amplified at Q401, Q402, Q404 and Q409, and enters the LPF to
remove harmonics. Then the signal goes to the antenna for transmission.
（3） APC Circuit