RTS DV3066 Service Manual

SERVICE MANUAL

© 2016 Jan.

CONTENTS

CIRCUIT DESCRIPTION ............................ 1

PARTS LIST ............................................... 5

ADJUSTMENT ........................................ 21

PC BOARD..................................................24

SCHEMATIC DIAGRAM............................ 26

BLOCK DIAGRAM..................................... 28

SPECIFICATIONS...................................... 29

DV3066

CIRCUIT DESCRIPTION

1. Frequency Configuration

The frequency configuration is shown in Figure 1 and

Table 1.

ANT

ANTSW

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

IFSYSTEM

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

ANTSW

CF30 00

CF500

IF,MIX,DE T

U503

Q512

X2

MULTIPLY

2nd LocalOS C

BPF

X500

TCXO

RFAMP

Q506

VFO

Tunin gvoltage

U201
MPU

19.200M Hz

BPF

U204A

AFAMP

MIXER

Q507

VCO

XF3000 ,XF30 01

1st Local OSC

(PLL)

LV

MCF

PLL

AFPA AMP

U205

IFAMP
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

FMSYSTEM

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

1stIFinput
(38.85MHz)

U503
FMIC

2ndlocalOSC

(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)

3-2. Receive Signalling
3-2-1 Low-speed data（CTCSS/DCS）

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

SPMUTE

PA1

RSSI

P71

SQ

P70

MIX

Noise
comp

Rectifier

Buffer

Local

OSC

CF3000

450kHz

. (See Fig.5)

RSSI

T3000

IFAMP

111213141516

654321

5R

10

Quad ratu re

detector

Inve rter

AMP

R593

C581

R595

Nois e
AMP

AFOUT

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

U204A Q206,Q207
AMP

VOL

Q201,Q205,

U205
AFPA

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)

AbandFMIFICU503

IF AMP

DET

SQL

40

P70

U201
MPU

LNOUT

AFsignal

98

PA1

DEMOD

U202

DTMFdecoder

P20,P21,P22,P23, P64,P65

27 Audio

92

SPMUTE

Fig.5

AFAMP

U204A(1/2)

VOL

U205
AFPA

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

RFAMP

Q516

RFAM

LPF

PA0

(U201 Pin91)

PLLDATA

19.200MHz

5C

D516, D517

REFOSC

Ripple

Fil te r

Q504

T/RSW

Q519

Q518

VCO

PLLICU504

I/N

I/M

Q517

BUFFAMP

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

MICAM 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)(

Q515 Q513 Q505 D506

DRIVE

AMP

VDDVG VG

+BA TT

AMP

RF

R589

R590

R591

RF

FI NALAMP

APC

(U201)

U502A
(1/2 )

Fig.8

Q208

LPF

(SPLATTERFILTER)

ANTSW

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

C200 SMT CAPACITOR 0603 1 104±10% 50V
C201 SMT CAPACITOR 0603 1 102±10% 50V
C202 SMT CAPACITOR 0603 1 473±10% 50V
C203 SMT CAPACITOR 0603 1 102±10% 50V
C204 SMT CAPACITOR 0603 1 103±10% 50V
C205 SMT CAPACITOR 0603 1 104±10% 50V
C206-C212 SMT CAPACITOR 0603 7 103±10% 50V
C213 SMT CAPACITOR 0603 1 104±10% 50V
C214-C220 SMT CAPACITOR 0603 7 103±10% 50V
C221 SMT CAPACITOR 0603 1 183±10% 50V
C222 SMT CAPACITOR 0805 1 685±10% 50V
C223 SMT CAPACITOR 0603 1 224±10% 50V
C224 SMT CAPACITOR 0603 1 105±10% 50V
C225 SMT CAPACITOR 0603 1 NO USE
C226 SMT CAPACITOR 0805 1 105±10% 50V
C227 SMT CAPACITOR 0805 1 104±10% 50V
C228-C233 SMT CAPACITOR 0603 6 104±10% 50V
C234 SMT CAPACITOR 0603 1 224±10% 50V
C235-C237 SMT CAPACITOR 0603 3 104±10% 50V
C238 SMT CAPACITOR 0603 1 332±10% 50V
C239 SMT CAPACITOR 0603 1 223±10% 50V
C240 SMT CAPACITOR 0603 1 104±10% 50V
C241 SMT CAPACITOR 0603 1 224±10% 50V
C242 SMT CAPACITOR 0603 1 104±10% 50V
C243 SMT CAPACITOR 0603 1 224±10% 50V
C244-C245 SMT CAPACITOR 0603 2 104±10% 50V
C246 SMT CAPACITOR 0603 1 273±10% 50V

DV3066

5

DV3066

PARTS LIST

Ref. No Parts No. Description of item Size (LxW)(mm) Qty Specification

C247-C248 SMT CAPACITOR 0603 2 20P±5% 50V
C249 SMT RESISTOR 0603 1 0R
C250 SMT CAPACITOR 0603 1 47P±5% 50V
C251 SMT CAPACITOR 0603 1 105±10% 50V
C252 SMT CAPACITOR 0603 1 100P±5% 50V
C253 SMT CAPACITOR 0603 1 56P±5% 50V
C254 SMT CAPACITOR 0603 1 220P±5% 50V
C255-C258 SMT CAPACITOR 0805 1 225±10% 50V
C259-C260 SMT CAPACITOR 0603 2 100P±5% 50V
C261 SMT RESISTOR 0603 1 100R±5%
C262 SMT CAPACITOR 0603 1 103±10% 50V
C263 SMT CAPACITOR 0603 1 104±10% 50V
C264 SMT CAPACITOR 0603 1 30P±5% 50V
C265 SMT CAPACITOR 0603 1 103±5% 50V
C267 SMT CAPACITOR 0603 1 15P±5% 50V
C268 SMT CAPACITOR 0603 1 470P±5% 50V
C269 SMT CAPACITOR 0603 1 272±5% 50V
C270 SMT CAPACITOR 0603 1 473±5% 50V
C271 SMT CAPACITOR 0603 1 332±5% 50V
C272 SMT CAPACITOR 0603 1 224±10% 50V
C273 SMT CAPACITOR 0603 1 472±10% 50V
C274 SMT CAPACITOR 0603 1 332±5% 50V
C275 SMT CAPACITOR 0603 1 105±10% 50V
C276 SMT CAPACITOR 0603 1 680P±5% 50V
C277 SMT CAPACITOR 0603 1 332±10% 50V
C278 SMT CAPACITOR 0805 1 475±10% 50V
C279 SMT CAPACITOR 0805 1 225±10% 50V
C280 SMT CAPACITOR 0603 1 103±10% 50V

6

DV3066

PARTS LIST

Ref. No Parts No. Description of item Size (LxW)(mm) Qty Specification

C281 SMT CAPACITOR 0603 1 102±10% 50V
C282 SMT CAPACITOR 0603 1 104±10% 50V
C283 SMT CAPACITOR 0603 1 122±10% 50V
C284-C286 SMT CAPACITOR 0603 3 103±10% 50V
C287 SMT CAPACITOR 0603 1 470P±5% 50V
C288 SMT CAPACITOR 0603 1 104±10% 50V
C500 SMT CAPACITOR 0603 1 103±10% 50V
C501 SMT CAPACITOR 0603 1 102±10% 50V
C502 SMT CAPACITOR 0603 1 103±10% 50V
C503-C508 SMT CAPACITOR 0603 6 102±10% 50V
C509 SMT CAPACITOR 0603 1 103±10% 50V
C510 SMT CAPACITOR 0603 1 104±10% 50V
C511 SMT CAPACITOR 0603 1 102±10% 50V
C512-C525 SMT CAPACITOR 0603 14 102±10% 50V
C526-C536 SMT CAPACITOR 0603 11 103±10% 50V
C537-C551 SMT CAPACITOR 0603 15 103±10% 50V
C552 SMT CAPACITOR 0603 1 103±10% 50V
C553 SMT CAPACITOR 0603 1 103±10% 50V
C554 SMT CAPACITOR 0805 1 105±10% 50V
C555-C556 SMT CAPACITOR 0603 2 105±10% 50V
C557 SMT CAPACITOR 0603 1 104±10% 50V
C558-C560 SMT CAPACITOR 0603 3 104±10% 50V
C561 SMT CAPACITOR 0603 1 102±10% 50V
C562-C565 SMT CAPACITOR 0603 4 104±10% 50V
C566 SMT CAPACITOR 0603 1 224±10% 50V
C567 SMT CAPACITOR 0805 1 470P±10% 50V
C568 SMT CAPACITOR 0603 1 15P±5% 50V
C569 SMT CAPACITOR 0603 1 9P±0.1P 50V
C570 SMT CAPACITOR 0603 1 120±5% 50V

7

DV3066

PARTS LIST

Ref. No Parts No. Description of item Size (LxW)(mm) Qty Specification

C571 SMT CAPACITOR 0603 1 12P±5% 50V
C572 SMT CAPACITOR 0603 1 10P±0.25P 50V
C573 SMT CAPACITOR 0603 1 NO USE
C574 SMT CAPACITOR 0603 1 6P±0.1P 50V
C575-C577 SMT CAPACITOR 0603 3 NO USE
C578 SMT CAPACITOR 0603 1 33P±5% 50V
C579 SMT RESISTOR 0603 1 2.2K±5%
C580-C581 SMT CAPACITOR 0603 2 220P±5% 50V
C582-C583 SMT CAPACITOR 0804 2 225±10% 50V
C584 SMT CAPACITOR 0603 1 102±10% 50V
C585 SMT CAPACITOR 0603 1 100P±5% 50V
C586 SMT CAPACITOR 0603 1 33P±5% 50V
C587 SMT CAPACITOR 0603 1 100P±5% 50V
C588 SMT CAPACITOR 0603 1 102±10% 50V
C589-C591 SMT CAPACITOR 0603 3 100P±5% 50V
C592 SMT CAPACITOR 0603 1 27P±5% 50V
C593 SMT CAPACITOR 0603 1 102±10% 50V
C594-C596 SMT CAPACITOR 0603 3 470P±10% 50V
C597 SMT CAPACITOR 0603 1 102±10% 50V
C598 SMT CAPACITOR 0603 1 103±10% 50V
C599 SMT CAPACITOR 0603 1 6P±0.1P 50V
C600 SMT CAPACITOR 0603 1 102±10% 50V
C601-C607 SMT CAPACITOR 0603 7 470P±10% 50V
C608 SMT CAPACITOR 0603 1 56P±5% 50V
C609 SMT CAPACITOR 0603 1 102±10% 50V
C610-C612 SMT CAPACITOR 0603 3 470P±10% 50V
C613 SMT CAPACITOR 0603 1 NO USE
C614 SMT CAPACITOR 0603 1 27P±5% 50V

8