QUANTUN QP-650 Plus User manual

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QP-650 Plus Service Manual
Quantun Electronics，
，，
，LLC

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Revised History
No: Date Decription Version Note
1 2010-3-9
Issue V0.1A

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Content
General……………………………………………………………………………3
Brief Introduction………………………………………………………………..4
Software Description…………………………………………………………..6
Circuit Description……………………………………………………………..10
CPU Pins…………………………………………………………………………15
Part List 1………………………………………………………………………..17
Adjustment Description……………………………………………………….49
Disassembly and Assembly………………………………………………..52
Exploded View………………………………………………………………..56
Part List 2……………………………………………………………………….57
PC Board View………………………………………………………………….58
Block Diagram…………………………………………………………………..62
Schematic Diagram…………………………………………………………..63
Specifications…………………………………………………………………66

QP-650Plus Software Specification
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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.
MODEL LIST
QP650 Plus, UHF, 450-470 MHz
Model Description
XMHQP-650U QP650 Plus, 450-470 MHz, 5W, 16CH
Accessories
QSBP0M080020
QS4502000000
QSAN0H410020
QC750100020
Li-Ion battery 1400 mAh
Belt clip
Antenna Whip 400-470 MHz
Programming cable kit with USB conector
QC750200010 Programming cable kit with serial port
SCHOM080020
SC1002 QP
-
650 Fast Charger
–
Base
only

QP-650Plus Software Specification
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Brief Introduction
1. Antenna
2. LED indicator
The light will glow red during transmission. The light will glow green during receiving. During
transmission, the light flashes red when the battery voltage is low.
3. Channel selector knob
Turn the channel selector knob to select from channels 1-16 (Channel 16 can be programmed by
your dealer as scan function).
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.

QP-650Plus Software Specification
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6. SK1 (Side Key) (programmable)
Your dealer may program the SK1 (long or short press) keys with one of the following auxiliary
functions respectively.
1)VOX
2)Power Level
3)monitor
4)monitor momentary
5)scan
6)squelch off
7)squelch off momentary
8)channel lock
9) battery indicator
7. Microphone
8. Speaker
9. External jack
Remove the jack cover and insert an earphone; 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 connectors
Connect the charging connectors with that on the charger to begin charging.

QP-650Plus Software Specification
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Software Specification
Radio Feature Description
1. Use channel selector knob to choose from 16 channels
2. Channel Annunciation, The feature enables radio to report the current channel number when power on or switching
channel,.
3. Channel Spacing
12.5KHz/20KHz/25KHz Narrow/Middle/wide Optional
4. High/low Power (Dealer programmable)
5. CTCSS/CDCSS
51+104 groups, user definable
6. DTMF PTT ID
7. Side key function programmable
8. Monitor
9. channel lock
10. Channel Scan (Priority channel and scan revert channel available)
11. VOX (9 levels)
12. Battery Save feature (Dealer programmable)
13. Time-out Timer (TOT)
14. Squelch Level Control (9 levels)
15. Low Battery Alert
16. Reset Mode
17. PC Programming
18. User Wired Clone Mode
19. Manual Adjust Mode
Radio Modes
1. User Mode:
User mode is conventional communication mode. Turn the power on, the radio enters user mode.
2. Reset Mode
(1) Turn channel selector knob to the corresponding position 16.
(2) Holding down PTT and Side key , and then turn the power on. After 2 seconds release PTT and Side key with
orange LED flashing.
(3) Press Side key for 3 seconds and meanwhile turn channel selector to CH13, the Red LED lights. Channel
data and settings begin to be initialized (Refer to the initial data table).when finished the red LED turn off.
Remarks: The data (frequency, CTCSS/CDCSS, channel function settings) will be changed once the radio is reset, and
part of functions will also be changed. Therefore, do not make this operation unless it’s very necessary, such as
changing the EEPROM, etc.

QP-650Plus Software Specification
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3. PC Programming Mode
The following parameters can be set through programming software (Refer to the figure2):
（ 1 ） Receive frequency and transmit frequency
（ 2 ） Receive signaling and transmit signaling
（ 3 ） N/M/W setting
（ 4 ） High/low power
（ 5 ） Busy channel lockout
（ 6 ） Tail Elimination
（ 7 ） VOX level
（ 8 ） Squelch level
（ 9 ） Time-out timer
（ 10 ） DTMF PTT ID
（ 11 ） VOX level
（ 12 ） Scan mode
（ 13 ） Scan revert channel
（ 14 ） Priority scan channel
（ 15 ） Channel Annunciation
（ 16 ） Annunciation voice level
（ 17 ） Battery save
（ 18 ） Key assignment
Power level
Monitor mode
Squelch off mode
VOX toggle
Channel lock
Battery indicator

QP-650Plus Software Specification
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4. Manual Adjust Mode
(1) Enter the manual adjust mode
Turn channel knob to Channel1, Turn on the power while holding down PTT and Side key simultaneously for 2
seconds, orange LED will flashing two times., release the PTT and SK1 key , then press PTT button for 2 seconds,
the red led flashes and release the two keys again, the radio enters manual adjust mode.
(2) Select adjusting item
In manual adjust mode, select the adjusting item by turning the channel selector knob to CH2-CH16 while holding
down PTT and side key, the item are defined as follows:

QP-650Plus Software Specification
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Channel NO. Adjust item
2 TX Low Power
3 TX High Power
4 TX CDC Deviation
5 TX CTC(67Hz) Deviation
6 TX CTC(151.8Hz) Deviation
7 TX CTC(254.1Hz) Deviation
8 TX DTMF Deviation
9 VOX Level 1
10 VOX Level 5
11 TX Low battery threshold
12 RX sensitivity
13 Squelch open level 1
14 Squelch open level 9
15 Squelch shut level 1
16 Squelch shut level 9
(3) Adjusting Operation
When the radio enter a adjusting item, the channel selector is used to choose the frequency point and bandwidth,
the PTT and SK1 is pressed to upward/downward the adjusting value. The details is as following:
PTT/SK1
PTT→Increase
SK1→Decrease

QP-650Plus Software Specification
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CH. NO.
Defination
Frequency Bandwidth
1 F1 W
2 F2 W
3 F3 W
4 F4 W
5 F5 W
6 F3 M
7 F1 N
8 F3 N
9 F5 N
5. User Wired Clone Mode
(1). Turn on the power while holding down Side key for 2 seconds, green LED flash two times, the radio enters
wired clone mode.
(2). Press the PTT key to begin wired clone and slave radio red LED lights, when clone is completed, master radio
orange led lights, and slave radio red Led goes out.
6. Aging Test Mode
Aging Test Mode is used for quality control in factory.

QP-650 Plus Circuit Description
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Circuit Description
1. Power Supply
Power supply of the radio is derived from the battery, which supplies battery B+ through power
switch. U608 supplies 5V (5M) voltage for the control circuit. U607 supplies 3V voltage for the PLL circuit.
And U200 supplies voltage for the transmit(V_TX), receive(V_RX) and vco(V_SAVE) circuit.
Fig. 1 Power Supply Block Diagram
2 ．
．．
． PLL frequency synthesizer
PLL circuit generates the first local oscillator signal for reception and RF signal for transmission.
Fig.2 PLL Block Diagram

QP-650 Plus Circuit Description
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PLL circuit
Step frequency of PLL can be 2.5 KHz, 5.0 KHz or 6.25 KHz. A 12.8MHz reference oscillator signal
is divided at U610 by a counter to generate a 2.5 KHz, 5.0 KHz or 6.25 KHz reference frequency. Output
signal from VCO is buffer amplified by Q103 and divided at U610 by a frequency divider. The divided
signal is compared with 2.5 KHz, 5.0 KHz or 6.25 KHz reference signal in the phase comparator of U610.
The output signal from phase comparator is filtered through a low pass filter to generate a level D.C., and
the level D.C. controls oscillator frequency by controlling VCO.
VCO
The operating frequency is generated by Q100 in transmit mode and by Q101 in receive mode.
Operating frequency generate a control voltage by phase comparator to control varactor diodes so that
the oscillator frequency is consistent with the MCU preset frequency(D100 、 D101 、 D104 and D105 in
transmit mode, and D102 、 D103 、 D106 and D107 in receive mode). T/R pin is set high level in receive
mode, and low level in transmit mode. The output from Q100 and Q101 is amplified by Q103 and sent to
buffer amplifier.
Unlock detector
An unlock condition appears if low level appears at MUXOUT pin of U610. Transmission is
forbidden if this condition is detected by microprocessor.
3 ．
．．
． Receiver
The receiver utilizes double conversion superheterodyne
Fig. 3 Receiver Section Configuration

QP-650 Plus Circuit Description
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Front-end RF Amplifier
The signal from antenna is amplified at RF amplifier (Q500) after passing through a transmit/receive
circuit and a band pass filter. Before passing the first mixer, the amplified signal is filtered through
another band pass filter to remove unwanted signals.
First Mixer
The signal from RF amplifier is mixed with the first local from PLL frequency synthesizer circuit at
the fix mixer (Q501) to create a 38.85MHz first IF signal. The first IF signal is then fed through a crystal
filter (XF1) to further remove unwanted signals.
IF Amplifier
The first IF signal is amplified by Q502 before passing through crystal filter after crystal filter and
then enters IF processing chip U200. The signal from U200 is mixed with the second oscillator signal
again in U200 to create a 450 KHz second IF signal. The second IF signal then passes through a
450KHz ceramic filter to eliminate unwanted signals before it is amplified and detected in U200.
4. Transmitter
AF and signaling
AF signal from the microphone is amplified and low-pass-filtered in U200, which also enters
CYC/CDC/DTMF etc signaling generated by CPU. The U200 processed mixing signal enters VCO for
direct FM modulation (see fig.5).
RF Power Amplifier
The transmit signal from VCO buffer amplifier （ Q102 ） is amplified by Q104 and Q400. The
amplified signal is then amplified by the power amplifier Q402 and Q403 (including a two-stage FET
amplifier) to create 5.0W RF power (see Fig. 4).

QP-650 Plus Circuit Description
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Fig. 4 APC System
Antenna switch and LPF
Output signal from RF amplifier passes through a low-pass filter network and a transmit/receive
switch circuit comprised of D401 ， D501 and D502 before it reaches the antenna terminal. D501 and
D502 is turned on (conductive) in transmit mode and off (isolated) in receive mode.
APC
The automatic power control (APC) circuit stabilizes the transmit output power by detecting the
drain current of final stage amplifier FET. U430 (2/2) compares the preset reference voltage with the
voltage obtained from final current. APC voltage is proportional to the difference between auto detect
voltage and reference voltage output from U430 （ 1/2 ） . The output voltage controls FET power.
5. Base band and signaling system
The block diagram of signaling section is shown as figure 5.

QP-650 Plus Circuit Description
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Fig. 5 AF and Signaling Circuit
CTC/CDC
Transmit: CTC/CDC signaling produced by CTC_PLL pass a low pass filter and then enters
VCXO. CTC/CDC signaling produced by CTC_OUT pass a low pass filter and then mixed with AF
before enters VCO.
Receive: Demodulated signal enters MCU after pass U200. MCU then judges whether CTC/CDC
matches the preset values or not. According the result, the out tone will be controlled by AFMUTE.
DTMF
Transmit: The signal produced by MCU provides a TX and SP out tone, and is then applied to the
base band processing IC. The signal in mixed with the audio signal and goes to the VCO 。
AF
Transmit: AF signal from MIC enters base band processed IC for amplification, pre-emphasis etc.
after being amplified. And then it enters VCO for modulation.
Receive: Demodulated AF signal enters the base band processing IC for amplification,
de-emphasis etc. after being amplified. And then it enters AF power amplifier drived speaker.
Base band processed chip provides functions for processing signal as amplifying, filtering,
amplitude limiting.
6. Control system
The U611 CPU operates at 19.6608 MHz.
The block diagram of MCU control system is shown as following ：

QP-650 Plus Circuit Description
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Fig.6 MCU Block Diagram
Circuit in this section is mainly comprised of MCU, EEPROM etc.
MCU control circuit accomplishes the following functions: accomplish the reset initialization
according to the programmed feature of the radio when power on; detect keying signal and monitor
battery voltage; send necessary frequency data to PLL according to encode of the channel; switch and
control transmit/receive according to the signal input from PTT; turn on/off the mute circuit according to
the input signaling decode signal and squelch level signal; output control signal to control the light/off of
LED; control signaling process IC to perform tasks.
.

QP-650 Plus MCU PINS
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CPU Pins
PIN No. PIN Name I/O Description
1 NC
2 SDL I/O EEPROM DATA
3 MODE
4 NC
5 NC
6 RESET I Reset input
7 XOUT Crystal oscillator output pin
8 GND GND
9 XIN Crystal oscillator input pin
10 VCC I VCC
11 NC
12 DTMF O DTMF output
13 APC/TV O Power control/ receiver tuning out
14 PLLCLK O PLL clock output
15 NC
16 PLLEN O PLL strobe output
17 W/N O 0: Wideband control 1: Narrowband control
18 PLLDATA O PLL data output
19 NC
20 NC
21 M_band O Medium band control
22 SAVE O Power save control
23 NC
24 T/R O Receive/transmit VCO control
25 NC
26 RXD I/O Serial date input.
27 TXD I/O Serial date output.
28 SPV_C O SPV_C
29 LD I
PLL unlock detect
30 EN3 I Channel coded in
31 NC
32 EN2 I Channel coded in
33 EN1 I Channel coded in
34 EN0 I Channel coded in
35 NC
36 MIC_EN O MIC_EN
37 NC

QP-650 Plus MCU PINS
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PIN No. PIN Name I/O Description
38 NC
39 NC
40 LEDR O Red light control
： H ， lit ； L ， out
41 LEDG O Green light control
： H ， lit ； L ， out
42 PTT I PTT key IN
43 SK1 I Side Key1
44 EXT_DEV I EXT_DEV detect
45 APCSW O APC SW
46 NC
47 NC
48 NC
49 NC
50 BUSY I Squelch level input
51 BATT I Battery voltage detect
52 VOXDET I VOX level input
53 RSSI I RSSI level input
54 QT_IN I CTC/DCS in
55 CLK O
AN29160 CLK
56 DATA I/O
AN29160 DATA
57 EN O AN29160 EN
58 QT_OUT O QT_OUT
59 GND GND
60 BEEP O BEEP tone output
61 VCC I
62 VCC I
63 NC
64 SCL O EEPROM CLK

QP-650 Plus MCU PINS
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Part list 1
NO.
NO.NO.
NO.
P/N
P/NP/N
P/N Description
DescriptionDescription
Description Refer. NO.
Refer. NO.Refer. NO.
Refer. NO. Qty.
Qty.Qty.
Qty. Note
NoteNote
Note
1 1501061040
Capacitor 0603 0.1UF K 50V C100 1
2 1701084750
TAN-Capacitor 0805 4.7UF M 10V C101 1
3 1701121060
TAN-Capacitor 1206 0.1UF M 16V C102 1
4 1501041030
Capacitor 0402 0.01UF K 25V C105 1
5 1501041020
Capacitor 0402 1000PF K 50V C106 1
6 1501041010
Capacitor 0402 100PF J 50V C107 1
7 1501044700
Capacitor 0402 47PF J 50V C110 1
8 1501040300
Capacitor 0402 3PF B 50V C111 1
15010405 0
Capacitor 0402 0.5PF B 50V C112 1
10 1501040400
Capacitor 0402 4PF B 50V C113 1
11 1501040300
Capacitor 0402 3PF B 50V C114 1
12 1501040500
Capacitor 0402 5PF B 50V C115 1
13 15010605 0
Capacitor 0603 0.5PF B 50V C116 1
14 1501041040
Capacitor 0402 0.1UF K 16V C118 1
15 1501043 00
Capacitor 0402 3 PF J 50V C120 1
16 1501040300
Capacitor 0402 3PF B 50V C121 1
17 1501040400
Capacitor 0402 4PF B 50V C122 1
18 1501040300
Capacitor 0402 3PF B 50V C123 1