Kirisun DP770 User manual

DP770 Service Manual
Contents
1.General Introduction...................................................................................................................................3
1.1. Scope.......................................................................................................................................................................3
1.2. Safety Precaution...................................................................................................................................................3
2.External View and Functional Keys..........................................................................................................4
2.1. External View and Functional Keys.....................................................................................................................4
2.2. LED Indicator..........................................................................................................................................................5
3.Circuit Description......................................................................................................................................6
3.1. RF Section...............................................................................................................................................................6
3.1.1. Transmitter Circuit..................................................................................................................................6
3.1.2. Receiver Circuit .....................................................................................................................................8
3.1.3. Frequency Generation Unit ...................................................................................................................9
3.1.4. GPS Circuit..........................................................................................................................................10
3.2. Baseband Section................................................................................................................................................11
3.2.1. Power Section...................................................................................................................................... 11
3.2.2. Audio Section....................................................................................................................................... 11
4.Function Instruction and Parameters Setting .......................................................................................13
4.1. General Functions................................................................................................................................................13
4.2. Parameters Setting..............................................................................................................................................14
5.Assembly and Disassembly ....................................................................................................................17
5.1. Attaching and Detaching the Battery.................................................................................................................17
5.2. Attaching and Detaching theAntenna...............................................................................................................18
5.3. Attaching and Detaching the Belt Clip...............................................................................................................19
5.4. Detaching the Chassis.........................................................................................................................................19
5.5. Removing the PCB board from the Chassis....................................................................................................20
5.6. Detaching the Keypad Board from the Case....................................................................................................20
5.7. Exploded View......................................................................................................................................................22
6.Tune Mode .................................................................................................................................................25
6.1. Required parts in adjustment..............................................................................................................................25
6.2. Adjusting and checking method.........................................................................................................................25
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DP770 Service Manual
6.2.1. Frequency description.........................................................................................................................25
6.2.2. Adjustment Equipments.......................................................................................................................26
6.2.3. Adjustment instruction of TX................................................................................................................26
6.2.4. Receiver section adjustment instruction..............................................................................................28
6.2.5. GPS Performance Test Instruction......................................................................................................30
7.Main Specifications ..................................................................................................................................31
8.Repairing and Testing Equipments.........................................................................................................33
9.Basic Troubleshooting.............................................................................................................................34
Appendix 1 Material List（Electrics Parts）400-470MHz.........................................................................36
Appendix 2 Material List（Electrics Parts）136-174MHz.........................................................................54
Appendix 3 Material List (Structural Section)...........................................................................................66
Appendix Figure 1 DP770 UHF Main Board Top Side PCB View.............................................................69
Appendix Figure 2 DP770 UHF Main Board Bottom Side PCB View......................................................70
Appendix Figure 3 DP770 UHF Keypad Top Side PCB View...................................................................71
Appendix Figure 4 DP770 UHF Keypad Bottom Side PCB View.............................................................72
Appendix Figure 5 DP770 UHF Main Board Schematic Diagram............................................................73
Appendix Figure 6 DP770 UHF Keypad Schematic Diagram...................................................................85
Appendix Figure 7 DP770 VHF Main Board Top Side PCB View.............................................................86
Appendix Figure 8 DP770 VHF Main Board Bottom Side PCB View ......................................................87
Appendix Figure 9 DP770 VHF Keypad Top Side PCB View ...................................................................88
Appendix Figure 10 DP770 VHF Keypad Bottom Side PCB View...........................................................89
Appendix Figure 11 DP770 VHF Main Board Schematic Diagram..........................................................90
Appendix Figure 12 DP770 VHF Keypad Schematic Diagram...............................................................102
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DP770 Service Manual
1.General Introduction
1.1.Scope
This manual is used for maintenance and repairing of the DP770 digital handheld radio, and intended to be
used by experienced technicians and trained engineers. Changes may occur with the technology
development. To require latest technology development information, please contact our company or the
local dealer.
Before any repairing, please read this manual carefully.
1.2.Safety Precaution
Electromagnetic Radiation Energy of Radio
Radios will generate and radiate electromagnetic energy, and Kirisun Radios’ electromagnetic radiation
meets the demand of domestic and international standards. To ensure optimum efficiency of the radio and
reduce electromagnetic radiation, when using the radio, it should be perpendicular to the ground. Keep
your mouth 2-5cm away from the microphone.
Electromagnetic Interference
To avoid interference, please turn off the radio in the site which specifically forbids using radio, e.g. hospital,
airport, health center and etc.
Explosive harmful gases
In the place with explosive harmful gases, such as the lower deck of a hull, fuel or chemical storage,
transportation facilities, places that contain chemicals or dust particles or metal powder in the atmosphere,
radio should be shut down.
When getting close to the blast zone and detonator electric, radio should be turn off.
Charging or replacing battery is not allowed in the place with potential explosive gases.
Antenna Damage
Do not use the radio when the antenna is broken, which will cause a mild burn to your skin.
Replacing Spare Parts
Please try not to replace the spare parts which are not contained in the spare part list.
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DP770 Service Manual
2.External View and Functional Keys
2.1.External View and Functional Keys
No. Part Name No Part Name
A Antenna B
Volume/Channel Knob
Rotate the knob to adjust the
volume.Short press the key, the
feature of the knob switches from
adjusting the volume to changing
the channel.
C LCD Display 160*128, 65K colors, 1.8 TFT
LCD. D
Universal Connector for
Accessories
Connect USB programming cable,
earphone or some other
accessories.
E
Top Key (TK)
Programmable, default: short
press to enable emergency alarm,
long press to exit emergency
alarm.
F LED Indicator
G Side Key 1 (SK1)
Programmable, default: none. H PTT Key
I Side Key 2 (SK2) J Left Key
D
M
N
O
P
G
H
J
K
I
L
R
Q
E F
A
B
C
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DP770 Service Manual
Programmable, default: none. Press the key to select the items
shown at the bottom left of the
screen.
K Dial Key Press the key to send data or text
messages. L 4-way Navigation Key
M
Right Key
Press the key to select the items
shown at the bottom right of the
screen.
N
ON/OFF/Hookoff Key
Return to the standby screen.
Long press the key to turn on/off
the radio.
O Numeric keypad P MIC
Q Speaker
2.2.LED Indicator
•Red LED glows: Radio is transmitting.
•Green LED glows: Radio is receiving (voice, short message, or data) or there is an activity on the
channel.
•Orange LED glows: This means the call hang time period. That is, you can press PTT to talk while the
orange LED glows
•Orange LED flashes: Radio is in emergency status; or there is a missed call / incoming call alert; or the
radio is scanning.
•Red LED flashes: Radio is receiving emergency alarm or "power on check" failed.
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DP770 Service Manual
3.Circuit Description
3.1.RF Section
Figure 3-1 RF Schematic Diagram
3.1.1. Transmitter Circuit
Figure 3-2 Transmitter Circuit Diagram
Pre-Driver2 Drive-stage Final-stage Tx/Rx Switch Low-pass Filter
Microstrip
Matcher
APC
To RX
Gate voltage control
Subtracter
Sampling resistor
BATT+
I/V
convertor
Attenuator
To GPS
TEMP
Sensor
Close To Final PA
Temp Det Level
Antenna
FGU
Pre-Driver1
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DP770 Service Manual
The transmitter circuit includes three parts:
•Transmitter Power Amplifier
The carrier signal generated by the TX VCO is modulated and amplified, and feeds to the transmitter circuit
via the following steps.
Step1: The signal passes a Π-type attenuator, realizing segregative isolation between RF power amplifier
circuit and TX VCO.
Step2: The signal are pre-amplified by a pre-driver amplifier (UHF: Q301, VHF: Q72), providing further
segregative isolation between itself and the next level amplifier.
Step3: The signal goes to the next pre-amplifier and drive amplifier (RD01) to obtain further amplification,
guarantying to provide enough driver power signal to the final-stage amplifier (RD07) and obtain the final
power amplification..
Step4: After amplified by multiple amplifiers, the transmitter signal is processed by a microstrip line to
complete output impedance matching at the output of final-stage amplifier, to reduce the output loss caused
by impedance mismatch.
Step 5: The transmitter signal goes through the RX/TX switch and enters to the low-pass filter.
•Low-pass Filter Circuit of suppressing the harmonics
The low-pass filter is high-grade low-pass filter composed of lumped-parameter inductors and capacitors.
By this filter, the spurious signal within the stop band can be attenuated as much as possible while the
in-band ripple is within the required range.
•Auto Power Control Circuit (APC includes temperature detection circuit)
In the auto power control and temperature detection circuit, the drain current from the driver amplifier and
final-stage amplifier is converted to voltage via the sampling resistor and subtraction circuit which is
composed of the first operational amplifier.
This voltage is compared with theAPC control voltage of output by DAC at the second operational amplifier.
Then the error voltage controls TX power by controlling the bias voltage at the gate of amplifier (including
the driver amplifier and the final-stage amplifier. The temperature sensor IC detects the surface
temperature of the final-stage amplifier, and converts it to DC voltage. Then the DC voltage is compared
with the voltage corresponding to the protection temperature (generally 80% of the extreme temperature) of
the amplifier. If the temperature is too high, the bias voltage of the amplifier will be reduced until the surface
temperature falls below the protection temperature.
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DP770 Service Manual
3.1.2. Receiver Circuit
Figure 3-3 Receiver Circuit Diagram
The receiver circuit mainly comprises RF band-pass filter, low-noise amplifier, mixer, IF filter, IF amplifier
and IF processor.
•Receiver Front-end
The HF signal from the low-pass filter passes through the electrically tunable band-pass filter controlled via
APC/TV1 level, to remove out-of–band interference signal and to send wanted band-pass signal to the
low-noise amplifier (UHF:Q205,VHF:Q62). The amplified signal goes to a band-pass filter controlled via
TFV level to remove out-of-band interference signal generated during amplification, and to send wanted HF
signal to the mixer (UHF:Z201,VHF:Z10).
Meanwhile, the first local oscillator signal generated by VCO passes through the low-pass filter and also
goes to the mixer (UHF: Z201, VHF: Z10). In the mixer, the wanted signal and the first local oscillator are
mixed to generate the first IF signal (UHF: 73.35MHz, VHF: 51.65MHz). The signal passes a frequency
selective network composed of LC, to suppress carrier other than the first IF signal, and to increase the
isolation between the mixer and the IF filter. After that, the first IF signal is processed by the crystal filter
(UHF: Z202, VHF: Z11) and is sent to the two-stage IF amplifier circuit composed of 2SC5006 for
amplification. Then the amplified signal goes to the IF processor AD9864 (UHF: U201, VHF: U91) for
processing.
•eceiver Back-end
Figure 3-4 IF Processor Diagram
AD986
Antenna
OMAP13
Low-pass filter
Insertion loss = -1dB
-120dBm
-121dBm
Band-pass filter
Insertion loss = -3dB
-124dBm
Band- pass filter
Insertion loss = -3dB
-109dBm
Low noise amplifier
Gain = 18dB
-106dBm
Lo: 0dBm
-115dBm
Mixer
Insertion loss = -6dB
Crystal filter
Insertion loss = -6dB
IF amplifier
Gain = 25dB
Po-1dB = -24dBm
-121dBm
Clip at -24dBm
-96dBm
Point A
Point B
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DP770 Service Manual
The first IF signal (73.35MHz) output by the IF amplifier goes into AD9864 (UHF: U201, VHF: U91) via Pin
47 and completes the second mixer, where the signal is converted to the second IF signal (2.25 MHz). The
second IF signal is converted to digital signal via ADC sampling, and output via the SSI interface. Finally,
the digital signal is sent to DSP (OMAP138) for demodulation.
AD9864 employs reference frequency of 12.8MHz. The second local oscillator is composed of an external
oscillator, a varactor and some other components, to provide the (UHF: 71.1MHZ, VHF: 49.4MHz)
71.1MHz LO signal. The 18MHz clock input frequency of AD9864 is generated by the LC resonance loop.
3.1.3. Frequency Generation Unit
Figure 3-5 Frequency Generation Circuit Diagram
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