The frequency configuration is shown in Figure 1 and
Table 1.
ANT
ANTSW
FINAL
RX/TX:66~88MHz
RF
AMP
MIX
MCF
38.850MHz
DRIVE
PRE
DRIVE
Fig. 1 Frequency configuration
Double super heterodyne
Reception method
1st IF Frequency 38.85MHz (Upper)
2nd IF Frequency 450kHz (Lower)
Transmission method VCO direct oscillation amplification
Modulation Variable reactance phase modulation
Table 1 Basic configuration
2. Receiver
2-1. Front-end RF Amplifier
The received signal from the antenna passes through a
low pass filter and then through a transmit/receive switching
circuit (antenna switch) and enters the band-pass filter
(L520, L521).
The signal passing through the band-pass filter (L520,
L521) is amplified by with an RF amplifier (Q506), passes
through a band-pass filter (L524, L522) and enters the first
mixer (Q507).
These band-pass filters are tuned to a desired frequency
by varicaps (D507, D508, D509, D510). A tuning voltage
corresponding to the desired signal is applied to each
varicap through the P76 terminal (pin 32) of the MPU (U201)
to tune to the receive frequency. (See Fig. 2)
2-2. First Mixer
The received signal passing through the band-pass filter
(L524, L522) is mixed with the first local signal generated by
the VCO by the first mixer (Q507) to produce a first IF signal
(38.85 MHz) (Upper heterodyne). The first IF signal passes
through a MCF (Monolithic crystal filter: XF3000 and
XF3001) to remove unwanted components.
The first IF signal passing through the MCF (XF3000 and
CF
450KHz
IFSYSTEM
MULTI PLY
PLL
VCO
38.40MHz
AMP
TCXO
AF
MIC
AMP
SP
19.200MHz
MIC
XF3001) is amplified by an IF amplifier (Q511) and the
resulting signal enters the FM IC (U503).
ANT
D501,D 502
D506
ANTSW
CF30 00
CF500
IF,MIX,DE T
U503
Q512
X2
MULTIPLY
2nd LocalOS C
BPF
X500
TCXO
RFAMP
Q506
VFO
Tunin gvoltage
U201
MPU
19.200M Hz
BPF
U204A
AFAMP
MIXER
Q507
VCO
XF3000 ,XF30 01
1st Local OSC
(PLL)
LV
MCF
PLL
AFPA AMP
U205
IFAMP
Q511
.
SP
Fig.2
2-3. IF Amplifier Circuit
The first IF signal (38.85 MHz) amplified by the IF
amplifier (Q511) and the second IF signal (38.40 MHz)
generated by tripling the 19.200 MHz reference oscillator
frequency of the TCXO (X500) by Q512, are mixed in the
FM IC to produce a second IF signal (450 kHz) (Lower
heterodyne). The second IF signal passes through a
ceramic filter (CF3000) to remove unwanted components.
The second IF signal passing through the ceramic filter
(CF3000) passes through the IF amplifier in the FM IC
again and is detected to produced an audio signal. (See
Fig.2)
2-4.Wide/Narrow Switching Circuit
Narrow and Wide settings can be made for each channel
by switching the demodulation level. The WIDE (high level)
and NARROW (low level) data is output from U201, pin 11.
When a WIDE (high level) data is received, Q503 and
Q509 turn on.
When a NARROW (low level) data is received, Q503 and
Q509 turn off.
Q503 and Q509 turns on/off with the Wide/Narrow data and
the U503 detector output level is switched to maintain a
constant output level during wide or narrow signals. (See
Fig.3)
P63(U201)
H:Wide
L:Narrow
Q503
Q509
AFOUT
U503
FMSYSTEM
R509
R596
QUAD
Q511
IFOUT
C654
T3000
5R
Fig.3
1
DV3066
1
7
CIRCUIT DESCRIPTION
2-5.Squelch
A noise component is obtained by passing FM
detection output (FM IC pin 9) through an operational
amplifier in the FM IC and band-pass filter consisting of
R593, R594, R595, C580, C581. The noise component is
rectified in the FM IC to produce a DC voltage, which is
output from the N-REC terminal (pin 14) of the FM IC as
squelch voltage.
The squelch voltage enters the SQ terminal (pin 40) of
the MPU (U201) and is compared with the reference
voltage preset in the MPU to control audio signal
ON/OFF.
U201
MPU
1stIFinput
(38.85MHz)
U503
FMIC
2ndlocalOSC
(38.40MHz)
Fig.4
3. AF signal system
3-1. Audio amplifier circuit
The demodulated signal from U503 goes to Audio
processor through U201 (AF filtered, high-pass filtered,
de-emphasized , De-Scrambler, Expander, and Mux).
The signal then goes through an AF amplifier U204A
(1/2), an AF volume control, and is routed to an audio
power amplifier (U205), where it is amplified and output
to the internal speaker. (See Fig.5)
The output signal from FM IC (U503) enters the
microprocessor (U201). U201 determines whether the
CTCSS or DCS matches the preset value, and controls
the SP MUTE (PA1) and the speaker output sounds
according to the squelch results
SPMUTE
PA1
RSSI
P71
SQ
P70
MIX
Noise
comp
Rectifier
Buffer
Local
OSC
CF3000
450kHz
. (See Fig.5)
RSSI
T3000
IFAMP
111213141516
654321
5R
10
Quad ratu re
detector
Inve rter
AMP
R593
C581
R595
Nois e
AMP
AFOUT
9
87
To output sounds from the speaker, U201 sends a high
signal to the PA1 line and turns U205 on through Q201,
Q205, Q206 and Q207. (See Fig.4)
2-6.S Meter Circuit
The S meter voltage is output from the RSSI terminal
(pin 12) of the FM IC (U503) and input to the SM terminal
(pin 39) of the MPU. Then the voltage is converted from
analog to digital in the MPU to control the S meter display
on the LCD. (See Fig.4)
U201
AQUA
LPF
C580
R5594
U204AQ206,Q207
AMP
VOL
Q201,Q205,
U205
AFPA
SW
LS200
SP
J201
3-2-2 High-speed data (DTMF)
The DTMF input signal from the FM IC goes to pin 18
of U202. The signal is demodulated by DTMF
demodulator in U202. The demodulated data goes to the
MPU for processing. (See Fig.5)
AbandFMIFICU503
IF AMP
DET
SQL
40
P70
U201
MPU
LNOUT
AFsignal
98
PA1
DEMOD
U202
DTMFdecoder
P20,P21,P22,P23, P64,P65
27 Audio
92
SPMUTE
Fig.5
AFAMP
U204A(1/2)
VOL
U205
AFPA
Q201,Q205,Q206,Q20
SW
LS200
SP
J20
2
DV3066
P
CIRCUIT DESCRIPTION
4. PLL frequency synthesizer
The PLL circuit generates the first local oscillator signal
for reception and the RF signal for transmission.
4-1.PLL circuit
A reference frequency of 5 kHz or 6.25 kHz is produced
by dividing the 19.20 MHz reference frequency of the
TCXO (X500) with PLL IC (U504). Comparison frequency
is produced by amplifying VCO output with an RF amplifier
(Q520) and dividing it with the PLL IC.
The PLL synthesizer with 5 kHz and 6.25 kHz step is
configured by comparing phases of the reference
frequency and comparison frequency.
The phase difference between reference frequency and
comparison frequency passes through a charge pump i n
the PLL IC, then ripples are removed with a loop filter with
low-range passing characteristics to produce VCO control
voltage (lock voltage). (See Fig. 6)
4-2.VCO circuit
The VCO produces a desired frequency directly with a
Colpits oscillation circuit containing an oscillation transistor
(Q518) used for both transmission and reception.
The VCO control voltage is applied to varicap (D516,
D517) to produce a desired frequency.
The PA0 terminal (pin 91) of the MPU (U201) goes "L"
during transmission, and the R/T control switch (Q519) is
turned OFF to change oscillation frequency. (See Fig. 6)
CHARGE
PUMP
Q520
RFAMP
Q516
RFAM
LPF
PA0
(U201 Pin91)
PLLDATA
19.200MHz
5C
D516, D517
REFOSC
Ripple
Fil te r
Q504
T/RSW
Q519
Q518
VCO
PLLICU504
I/N
I/M
Q517
BUFFAMP
MOD
5KHz/6.25KHz
PHASE
COMPARATOR
5KHz/6.25KHz
MOD
Fig.6
5. Transmission signal system
5-1.Microphone Amplifier Circuit
The audio signal from the microphone passes through a
microphone amplifier (U207) and enters Audio processor
(U201).U201 is composed of Compressor, high-pass
filtered, pre-emphasis, Mux, Scrambler, limiter, low-pass
filtered, and MOD circuit. The signal then passes through a
low-pass filter (splatter fiIter) Q208 and cuts 3kHz and
higher frequencies. The resulting signal goes to the VCO
through the VCO modulation terminal for direct FM
modulation. (See Fig. 7)
U207
MICAM P
C
MI
U201
MUP
Fig.7
5-2. Encode Signalling
CTCSS/DCS/DTMF
A necessary signal for CTCSS/DCS/DTMF encoding is
generated by U201 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 adjusting the
balance. (See Fig. 7)
5-3. Drive and Final Amplifier Circuit
The signal from the T/R switch (D503 is on) is amplified
by the pre-drive (Q515) and drive amplifier (Q513) to
50mW. The output of the drive amplifier is amplified by the
RF power amplifier (Q505) to 5W (1W when the power is
low).
The RF power amplifier consists of two MOS FET stages.
The output of the RF power amplifier is then passed
through the harmonic filter (LPF) and antenna switch
(D506) and applied to the antenna terminal.
(See Fig. 8)
Fro m
T/R SW
D503)(
Q515Q513Q505D506
DRIVE
AMP
VDDVGVG
+BA TT
AMP
RF
R589
R590
R591
RF
FI NALAMP
APC
(U201)
U502A
(1/2 )
Fig.8
Q208
LPF
(SPLATTERFILTER)
ANTSW
U502B
(2/2 )
VCO
TCXO
ANT
LPF
3
DV3066
5-4. APC Circuit
The APC circuit always monitors the current flowing
through the RF power amplifier (Q505) and keeps a
constant current. The voltage drop at R589, R590 and
R591 is caused by the current flowing through the RF
power amplifier and this voltage is applied to the differential
amplifier U502(1/2). U502 (2/2) compares the output
voltage of U502 (1/2) with the reference voltage from U201.
The output of U502 (2/2) controls the VG of the RF power
amplifier, Drive amplifier and Pre-Drive amplifier to make
both voltages the same.
The change of power high/low is carried out by the
change of the reference voltage. (See Fig. 8)
6 Control Circuit
The microprocessor (U201) operates at a clock of
32.768KHz.The control circuit consists of a microprocessor
(U201) and its peripheral circuits. It controls the TX-RX unit.
U201 mainly performs the following:
(1) Switching between transmission and reception by the
PTT signal input.
(2) Reading system, group, frequency, and program data
from the memory circuit.
(3) Sending frequency program data to the PLL.
(4) Controlling squelch on/off by the DC voltage from the
squelch circuit.
(5) Controlling the audio mute circuit by the decode data
input.
(6) Transmitting tone and encode data.
6-1.
Memory Circuit
Memory circuit consists of the MPU (U201 and an
EEPROM (U203). An EEPROM has a capacity of 64k bits
that contains the transceiver control program for the MPU
and data such as transceiver channels and operating
features. (See Fig. 9)
Fig.9
6-2. Low battery warning
The battery voltage is monitored by the microprocessor
(U201). When the battery voltage falls below the voltage
set by the Low Battery Warning adjustment, the red LED
U201
CPU
U203
EEP R OM
flashes to notify the operator that it is time to replace the
battery. If the battery voltage falls even more (approx.
6.0V), a beep sounds and transmission is stopped.
Low battery warning Battery condition
The red LED flashes
during transmission
The red LED flashes
and a continuous beep
sounds while PTT
pressed.
BATT1
R2 04
The battery voltage is low but
the transceiver is still usable.
The battery voltage is low and
the transceiver is not usable to
make calls.
U201
38
P72
C200
R2 03
MPU
Fig.10
7. Power Supply
There are four 5V power supplies for the microprocessor:
5M,5C,5R, and 5T. 5M for microprocessor is always output
while the power is on. 5M is always output, but turns off
when the power is turned off to prevent malfunction of the
microprocessor.
5C is a common 5V and is output when SAVE is not set to
OFF.
5R is 5V for reception and output during reception.
5T is 5V for transmission and output during transmission.
4
SPARTS LIST
MAIN UNIT
Ref. No Parts No. Description of item Size (LxW)(mm)Qty Specification
2) SSG standard modulation
[Wide] MOD:1kHz,DEV:3kHz
[Narrow] MOD:1kHz,DEV:1.5kHz
1) CH: high
2) CH: Low
3) CH: high
PTT:ON
4) CH: Low
PTT:ON
Transmitter section
Item Condition
1. Transmit
frequency
2. High
power
Adjust
3. Min power
Adjust
4. Low power
Adjust
5. MAX DEV
Adjust
[Wide]
[Narrow]
6. MIC
Sensitivity
[Wide]
[Narrow]
TEST CH: center
PTT: ON
TEST CH: low, center, high
Battery terminal: 7.4V
PTT: ON
CH: low, center, high
Battery terminal: 7.4V
PTT: ON
CH: low, center, high
Battery terminal: 7.4V
PTT: ON
TEST CH: Center
Low
High
AG: 1kHz/150mV
Deviation meter filter
LPF: 15kHz
HPF: OFF
PTT: ON
TEST CH: Center
PTT: ON
TEST CH: center
AG: 1kHz/10mV
TEST CH: Center
PTT: ON
Measurement Adjustment
Test equipmentTerminalParts Method
Power meter
DVM
Measurement Adjustment
Test equipment TerminalParts Method
Frequency counter
Power meter
Ammeter
Power meter
Deviation meter
Oscilloscope
AG
AF VTVM
TC2
ANT
ANT
SP/MIC
connector
less than 3.7V ±0.2V
test
test
test
Programming
Software:
QPS-3066
0.9V or more
less than 3.7V
0.9V or more
Adjust to the
frequency
4.3kHz
(According to
the lager +, –)
2.1kHz
(According to
the lager +, –)
Check
Specifications
/Remarks
±0.2V
±0.2V
±0.2V
Specifications
/Remarks
Within ±100Hz
4.8W ±0.2W
1.5 A or less
2.0W ±0.2W
1.0 A or less
1.0W ±0.2W
0.8 A or less
±100Hz
±2.5kHz~3.9kHz:
±1.1kHz~1.9kHz
21
DV3066
ADJUSTMENT
Transmitter section
Item Condition
7. VOX 1
Writing
8. VOX 10
Writing
9. DCS
Balance
Adjust
10. CTCSS
Deviation
Adjust
11. DCS
Deviation
Adjust
[Wide]
12. DTMF
deviation
[Wide]
13. Battery
Detection
Warning
14. Battery
Detection
Check
TEST CH: Center
AG: 1KHz/5mV
TEST CH: Center
AG: 1kHz/15mV
TEST CH: Center
LPF: 3kHz
HPF:OFF
PTT:ON
TEST CH: Center
LPF: 3kHz
HPF:OFF
PTT:ON
TEST CH : center
LPF:15kHz
HPF:OFF
PTT:ON
BATT terminal voltage:6.0V
BATT terminal voltage:6.3V
PTT: ON
BATT terminal voltage:7.4V
PTT: ON
Low
High
Low
High
Receiver Section
Item Condition
1. Sensitivity
check
[Wide]
[Narrow]
TEST CH: Center
Low
High
SSG output: -120dBm(0.22μV)
SSG MOD: 3.0kHz
TEST CH: Center
SSG output: -119dBm(0.25μV)
SSG MOD: 1.5kHz
Measurement Adjustment
Test equipmentTerminalParts Metho d
Power meter
Deviation meter
Oscilloscope
AG
AF VTVM
Power meter
DVM
Measurement Adjustment
Test equipmentTerminalParts Metho d
SSG
DVM
Oscilloscope
AG
AF VTVM
ANT
SP/MIC
connector
ANT
ANT
BATT
terminal
ANT
Programming
Software:
QPS-3066
Adjust the waveform
0.75kHz ±100Hz
0.75kHz
3kHz
test
Check
Check
Specifications
/Remarks
±100Hz
±100Hz
The transceiver
cannot transmit.
Blinking of LED
No blinking of
LED
Specifications
/Remarks
12dB SINAD or
more
22
DV3066
ADJUSTMENT
Receiver Section
Item Condition
2. SQL1
(Threshold)
writing
[Wide]
[Narrow]
3. SQL9
(Tight)
writing
[Wide]
[Narrow]
TEST CH: Center
Low
High
SSG output: –127dBm (0.1μV)
SSG MOD: 3.0kHz
TEST CH: Center
SSG output: -125dBm(0.126μV)
SSG MOD: 1.5kHz
TEST CH: Center
Low
High
SSG output: –117dBm (0.316μV)
SSG MOD: 3.0kHz
TEST CH: Center
SSG output: -115dBm(0.4μV)
SSG MOD: 1.5kHz
Measurement Adjustment
Test equipmentTerminalParts Metho d
Programming
Software:
QPS-3066
Writing
Specifications
/Remarks
Squelch open
23
PC board views
DV3066
24
PC board views
DV3066
25
DV3066
VFO
C584
VFO
SCHEMATIC DIAGRAM
D507
HVC376(B9)
C642
27P
5P(B)
C617
2P(B)
BATT
1
3
C538
103P
VFOC595
RF AMP
471P
R576
1M
R583
D508
HVC376(B9)
27K
Q506
C643
27P
C596
C634
471P
C636
R534
3P(B)
47K
L521
220NH-X
R580
R581
10R
10R
C557
104P
U502B
Q500
DTA144EE
7
LM2904V
R539
22K
C665
102P
R601
R541
100R
100K
R606
8K2
D515
MA2S360
C659
24P
C630
C622
R605
47P
0P5(B)
6K8
C641
56PR530
R599
680R
3
D
1
G1
2
4
G2
S
3SK318
C597
102P
R518
220R
C504
102P
R511
56K
R535
56K
C503
C598
102P
103P
R521
10K
R544
4K7
Q514
DTC144EE
C561
102P
C518
102P
R563
47K
D505
R602
BA892
2K7
C657
1P5(B)
C609
102P
L536
L538
68NH-X
68NH-X
C579
2K2
D516
JDV2 S1 4E( FH )
L539
10uH
C519
102P
D517
JDV2 S1 4E( FH )
R547
680R
E506
0.22uF/35V
E507
R588
390R
22uF/16V
R603
NOUSE
R512
NOUSE
5C
R545
R0
Q508
DTA143ZE
R542
100K
L505
271T
R523
10K
D509
HVC376(B9)
C644
27P
L524
220NH-X
C583
225P
Q519
2
3
2SK1824
R577
1M
L527
NOUSE
C619
C621
5P(B)
5P(B)
C620
2P(B)
C572
10P(C)
L528
82NH
5R
L500
271T
D512
47K-NTC
D
S
C648
NOUSE
Q502
RT1N141U
5R
C587
101P
C520
102P
G
C521
102P
R519
10K
C539
C574
103P
6P(B)
VFO
R548
47K
D519
BA892
R543
100K
C563
104P
1
R561
68K
Q521
2
D
1
3
G
S
NOUSE
R608
NOUSE
3.3M
R609
NOUSE
R584
82K
102P
R578
1M
C667
NOUSE
L522
220NH-X
C647
10P(C)
5C
R610
NOUSE
C565
104P
D510
HVC376(B9)
R555
82K
C645
27P
C601
C599
471P
6P(B)
R604
4K7
R536
150K
C506
C627
102P
10P(C)
R558
L529
82K
270NH
L501
271T
C505
102P
R526
100R
E500
106P/16 V
C651
15P
R594
180K
R595
3K9
C522
102P
C666
NOUSE
R607
NOUSE
RP500
5
6
7
8
1K*4
C607
471P
C555
105P
C551
103P
R509
1K8
R569
3K3
C548
103P
4
3
2
1
R596
1K5
9
C580
8
221P
C581
221P
2nd IF 450KHz
E502
10uF/10V
C510
104P
3
1
10
AF OUT
R593
270K
1
R522
10K
Q509
RT1P141U
T30 00
3
450K(C24)
1
C654
82P
11
QUAD
U501
TJ5205SF-50
Vin
CE3NC
IF OUT
CF3000
CFW450F
C558
104P
1
2
R537
150K
12
RSSI
GND
2
MIXER
Q507
G1
G2
3SK318
Q510
RT1P141U
C560
104P
C559
104P
13
N-DET
C549
103P
SQ1-UHF
W/N-CONTROL
RSSI
AF1-UHF
TX ENABLE
PO WE RCON TROL A PC
RX ENABLE
RX/TX CONT
MOD-AUDIO
CX ENABLE
C610
471P
Vout
PLL LD LINE
PLL CLOCK LINE
PLL DATA LINE
PLL STB ENAB LE
MOD-SUB
3
D
4
S
C528
103P
R585
10R
C507
102P
15
14
N-REC
5
4
C612
471P
R540
100K
GND
C566
224P
E503
10uF/10V
16
AA32416
R513
NOUSE
MIX IN
OSC IN1OSC OUT2MIX OUT3VCC4IF IN5DEC6FIL OUT7FIL IN