Yaesu VR-120D, VR-12D Technical Supplement

COMMUNICATIONS RECEIVER

VR-120D

Technical Supplement

EH011M90A

Introduction

This manual provides technical information necessary for servicing the Yaesu VR-120D Communications Receiver. Information on its installation and operation can be found in the VR-120D Operating Manual, which is provided with the receiver, and Accessory information may be found in the documents accompanying the optional equipment.

The VR-120D is a high-performance miniature communications receiver providing general coverage reception from 100 kHz to 1300 MHz on the AM, and FM (Wide and Narrow bandwidths) modes (this coverage includes the AM and FM broadcast bands, HF Short-wave Bands up to 16 MHz, VHF and UHF TV bands, the VHF AM aircraft band, and a wide range of commercial and public safety frequencies!).

VERTEX STANDARD CO., LTD.

4-8-8 Nakameguro, Meguro-Ku, Tokyo 153-8644, Japan

VERTEX STANDARD

US Headquarters

17210 Edwards Rd., Cerritos, CA 90703, U.S.A.

International Division

8350 N.W. 52nd Terrace, Suite 201, Miami, FL 33166, U.S.A.

YAESU EUROPE B.V.

P.O. Box 75525, 1118 ZN Schiphol, The Netherlands

YAESU UK LTD.

Unit 12, Sun Valley Business Park, Winnall Close Winchester, Hampshire, SO23 0LB, U.K.

VERTEX STANDARD HK LTD.

Unit 5, 20/F., Seaview Centre, 139-141 Hoi Bun Road, Kwun Tong, Kowloon, Hong Kong

Servicing this equipment requires expertise in handling surface mount chip components. Attempts by unqualified persons to service this equipment may result in permanent damage not covered by warranty. For the major circuit boards, each side of the board is identified by the type of the majority of components installed on that side. In most cases one side has only chip components, and the other has either a mixture of both chip and lead components (trimmers, coils, electrolytic capacitors, packaged ICs, etc.), or lead components only.

While we believe the technical information in this manual is correct, VERTEX STANDARD assumes no liability for damage that may occur as a result of typographical or other errors that may be present. Your cooperation in pointing out any inconsistencies in the technical information would be appreciated. VERTEX STANDARD reserves the right to make changes in this receiver and the alignment procedures, in the interest of technological improvement, without notification of owners.

Contents

Specifications ............................................................................................................................................... 2

Exploded View & Miscellaneous Parts ..................................................................................................... 3

Circuit Description ...................................................................................................................................... 5

Alignment ..................................................................................................................................................... 7

Block Diagram .............................................................................................................................................13

Board Unit (Schematics, Layouts & Parts)

CNTL•AF Unit ........................................................................................................................................................ 15

RF Unit ....................................................................................................................................................................23

Alignment

Note:

Specifications

Frequency Range: USA: 100 kHz ~ 1299.995 MHz (Cellular Blocked)

EXP: 100 kHz ~ 1299.995 MHz

(Frequency range is varied per local law. Ask your YAESU dealer

for details for frequency range in your country.)

Receiving Mode: AM/FM/WFM

Circuit Type: Triple Super-heterodyne

Memory Channels: 640 Channels

Memory Bank: 10 Banks (@ 64 Channels)

Antenna Impedance: 50-ohm unbalanced, BNC receptacle

Intermediate Frequencies: 248.45 MHz, 15 MHz, 450 kHz

Sensitivity (Typical): 200kHz ~ 5 MHz: AM 3.5 dBµ (1.5 µV)

5 ~ 160 MHz: AM -4.4 dBµ (0.6 µV)

FM -10.4 dBµ (0.3 µV)

WFM-1.0 dBµ (0.9 µV)

160 ~ 370 MHz: AM -4.4 dBµ (0.6 µV)

FM -10.4 dBµ (0.3 µV)

WFM-4.4 dBµ (0.6 µV)

370 ~ 520 MHz: FM -10.4 dBµ (0.3 µV)

WFM0 dBµ (1.0 µV)

520 ~ 1300 MHz: FM -3.0 dBµ (0.7 µV)

WFM9.5 dBµ (3.0 µV)

Selectivity: WFM: 200 kHz/-6 dB

AM/FM: 16 kHz/-6 dB

Conducted Spurious Emission: Less than -54 dBm

Supply Voltage: 2.2 ~ 3.5 V DC; Internal Battery (Nominal: 3.0 V DC)

5.5 ~ 10.0 V DC (EXT DC)

Current Consumption: Approx. 95 mA (Receive, AF Output 50 mW, 8-ohm)

Approx. 15 mA (Standby, Saver 1:4 on)

Approx. 55 mA (Standby, Saver off)

Operating Temp.: -10 °C ~ +50 °C

AF Output: Approx. 80 mW (8-ohm)

Case Size: 85 x 59 x 26 mm (H x W x D) w/o knob

Weight: Approx. 195 g w/battery & antenna

Specifications are subject to change without notice.

Exploded View & Miscellaneous Parts

No. VXSTD P/N DESCRIPTION QTY.

U07240307 PANHEAD SCREW M2x4B#3 2

U9900119 TAPTITE SCREW M2x5B#3 2

U07125301 PANHEAD SCREW M1.7x2.5#3 3

À Á

VXSTD P/N DESCRIPTION QTY.

S6000335 HAND STRAP 1

RA014370B BELT CLIP 1

U9900097

BINDING HEAD SCREW M3x5.5B

S8001937

LCD PANEL (YAESU)

S8001931 ANTENNA PACKING

S8100999 ANTENNA

S8002007 FRONT CASE ASSY (W/SP NET)

S8001941 VOLUME NUT

S8001942

NUTANTENNA

S8001930 SQL KNOB

S8001929 VOL KNOB (W/SPRING)

S8001932 SQL GUM PACKING

S8001928 DIAL KNOB (W/SPRING)

S8001938 BUTTON PLATE

S8001998 GUM PACKING

S8001934 RUBBER CONTACT

S8001000 SPEAKER

S8001958 LCD TAPE

S8001955 TAPE

S8002002

CONTACT C

S8002004 CUSHION

S8101164 (USA) S8101165 (B1) S8101166 (B2) CNTL.AF Unit

S8100788

ANTENNA CONNECTOR

S8001939 WATER PROOF FILM

S8001999 FRAME

S8101168 RF Unit

S8101008 BAR ANTENNA ASSY

S8001736 CONTACT B

S8001947 CONTACT D

S8001996 REAR CASE

S8001944 BATTERY PACKING

S8001926

BATTERY COVER

S8001737 GUM CUSHION

S8001734 CONTACT C

S8001948 GUM CUSHION

S8001927 CLAMPER

S8002003 LIGHT SEAL

S8002005 RUBBER CONNECTOR

S8001954 REFLECT SHEET

S8001957

LCD FILE S8001951 LCD BACK PLATE

S8101007 LCD

S8001952 LCD COVER

S8002001

CONTACT B

S8002000

CONTACT A

Exploded View & Miscellaneous Parts

Note:

Circuit Description

VR-120D separates into two substrate blocks. It is

RF unit and CNTL•AF unit.

ATT, ANT band path filter, bar ANT for AM,

RFAMP, 1st•2ndMIX, 2ndIF-AMP, 3rdIF-DETIC,

PLL, 1st•2nd-VCO, AMDET circuit are had by the

RF unit. Also, the CNTL•AF unit has a CPU, LCD,

a power, AUDIO circuit, EEPROM.

RF Unit

The signal which entered from ANT is stored in the

band path filter below the entering to the ATT

circuit.

It is amplified by RF-AMP Q216, Q217 which is

common after the band path filter passage.

The amplified RF signal entry to 1st-MIX Q218

(µPC2757T) with the 1st local signal, it makes a 1st

IF signal.

CNTL•AF unit

The detected signal from the RF substrate, which is

amplified by Q130 (UMX2N), and volume

controlled signal amplified by Q123 (TA31056F),

and it outputs a sound from the speaker.

The DC input of 3V, which boosts the voltage to

3.5V by the DC-DC converter Q116

(XC6371A351PR). It is stabilized to 3.2 V by Q118

(S-81332HG-KC).

The main microprocessor is Q101 (HD643837S).

EEPROM is Q115 (AT24C64N-10SI1.8).

The reset IC is Q112 (RN5VL20AA).

The 10V boost circuit for RF VCO, which boosts

and detects by Q119, Q120, Q121 (RB706F).

Q122 (2SC4617R) is a ripple filter.

The 1st local oscillator is VCO Q241 (2SC5006). and

oscillated signal is amplified in the buffering in

Q240, Q239 (2SC5006).

The 1st-IF signal of 248.45MHz which passed the

SAW filter of F202 are input to 2nd-MIX Q219

(2SC5006), it mix with the 2nd local signal of

263.45MHz, and makes a 2nd-IF signal.

Amplifying the 2nd-IF in Q220 2SC4915, and It

detects and it gets a speech signal by IF IC of Q221

(TA31136FN).

3rd-IF is 450kHz. The AM detection is Q231

(UMX2N), it amplifies 3rd-IF signal and Q232

(RB520S-30) detects AM.

2nd-VCO is oscillated by Q229, and it is amplified

by Q228.

PLL IC is Q235 (MB15F02PFV). It forms 1st and

2nd PLL circuit.

The standard crystal oscillation circuit is Q234

(2SC4617), it oscillates 14.55 MHz crystal.

The loop filter for 1st local is Q236 (2SK1580), its

active type, and the loop filter for 2nd local is passive

type by CR.

Circuit Description

Note:

Alignment

Introduction

The VR-120D has been carefully aligned at the

factory for the specified performance across the

amateur band. Realignment should therefore not

be necessary except in the event of a component

failure. All component replacement and service

should be performed only by an authorized Vertex

Standard representative, or the warranty policy may

be voided.

The following procedures cover the sometimes

critical and tedious adjustments that are not

normally required once the transceiver has left the

factory. However, if damage occurs and some parts

are replaced, realignment may be required. If a

sudden problem occurs during normal operation,

it is likely due to component failure; realignment

should not be done until after the faulty component

has been replaced.

We recommend that servicing be performed only

by authorized Vertex Standard service technicians

who are experienced with the circuitry and fully

equipped for repair and alignment. Therefore, if a

fault is suspected, contact the dealer from whom

the transceiver was purchased for instructions

regarding repair. Authorized Vertex Standard

service technicians realign all circuits and make

complete performance checks to ensure compliance

with factory specifications after replacing any faulty

components. Those who do undertake any of the

following alignments are cautioned to proceed at

their own risk. Problems caused by unauthorized

attempts at realignment are not covered by the

warranty policy. Also, Vertex Standard must reserve

the right to change circuits and alignment

procedures in the interest of improved performance,

without notifying owners. Under no circumstances

should any alignment be attempted unless the

normal function and operation of the transceiver

are clearly understood, the cause of the malfunction

has been clearly pinpointed and any faulty

components replaced, and the need for realignment

determined to be absolutely necessary.

Required Test Equipment

The following test equipment (and thorough

familiarity with its correct use) is necessary for

complete realignment. Correction of problems

caused by misalignment resulting from use of

improper test equipment is not covered under the

warranty policy. While most steps do not require

all of the equipment listed, the interactions of some

adjustments may require that more complex

adjustments be performed afterwards. Do not

attempt to perform only a single step unless it is

clearly isolated electrically from all other steps. Have

all test equipment ready before beginning, and

follow all of the steps in a section in the order

presented.

r RF Signal Generator with calibrated output level

at 1300 MHz

r Deviation Meter r Frequency Counter: ±0.1 ppm accuracy at 500

MHz

r DC Voltmeter: high impedance r AF Dummy Load: 8-Ohms, 1W

Note: Signal levels in dB referred to in this procedure

are based on 0 dBµ = 0.5 µV (closed circuit).

Alignment Preparation & Precautions

Correct alignment requires that the ambient

temperature in the repair shop be the same as that

of the receiver and test equipment, and that this

temperature be held constant between 20 °C and

30 °C (68° ~ 86° F). When the receiver is brought

into the shop from hot or cold air it should be

allowed some time for thermal equalization with

the environment before alignment. If possible,

alignments should be made with oscillator shields

and circuit boards firmly affixed in place. Also, the

test equipment must be thoroughly warmed up

before beginning.

Alignment

AF Dummy Load

Frequency Counter

RF Sinal Generator

SINAD Meter

Regulated

Test Setup

Set up the test equipment as shown below for

receiver alignment.

6.0V PSU

8-Ohms, 1W

VCO VCV

r Connect the DC voltmeter to TP3, and referring

to table below, tune the VR-120D to each

frequency listed.

Then confirm that the correct voltage is present.

Frequency VCV Voltage

0.500 MHz 0.15V ~ 0.55V

116.455 MHz 6.30V ~ 8.60V

116.550 MHz 0.12V ~ 0.60V

1299.950 MHz 5.40V ~ 6.60V

FM Discriminator Adjustment

r Connect the AF Milivoltmeter and 8-ohm resistor

to the SP jack, and connect the RF Signal

generator (SSG) to ANT jack.

r Set the receiver to 100.020 MHz, NFM mode. r Tune the SSG to 100.200 MHz with ±3.5 kHz

deviation ±1 kHz tone modulation, and set the

output level to 60 dBµ.

r Adjust L229 for maximum indication on the AF

Milivoltmeter.

PLL Reference Frequency Adjustment

r Disable the Battery Save;

m Press the [SCN] key while press and holding

the [FUNC] key.

m Rotate the DIAL knob to select the display to

"SAVE."

m Rotate the DIAL knob while press and holding

the [FUNC] key to change the display to "OFF."

m Press the [V/M] key to disable the battery saver

and exit to normal operation.

r Connect the Frequency Counter to TP1, and set

the receiver to 100.050 MHz, NFM mode. r Adjust C305, if necessary, so the counter

frequency is within ±200 Hz of 348.500 MHz.

RF Voltage

r Connect the DC voltmeter to TP2, and confirm

DC voltmeter reading 3.05~3.25V.

SQL Level/S-Meter Adjustment

Preparation

r Set the receiver to 1250.375 MHz, NFM mode,

then disable the OFF-timer function and set the

ATT to OFF.

r Press and hold the [SCAN] key for 2 seconds,

the rotate the DIAL knob to select the display to

"SL."

r Press and hold the [SCAN] key for 2 second while

press and holding the [FUNC] key. "LOW W "

will appears on the display. Sounds a beep.

r Tune the receiver to 123.125 MHz. r Press and hold the [SCAN] key for 2 seconds,

the rotate the DIAL knob to select the display to

"SS."

r Press and hold the SCAN key for 2 second while

press and holding the [FUNC] key. "ST W " will

appears on the display. Sounds a beep.

Alignment Points

L229

FM Discriminator Adjust

Alignment

TP3

VCO VCV: DC voltmeter

TP2

RF Voltege: DC voltmeter

C305

PLL Reference Frequency Adjust

TP1

PLL Reference Frequency Adjust: Frequency Counter

Alignment

r Tune the receiver to 448.250 MHz. r Press and hold the [SCAN] key for 2 seconds,

the rotate the DIAL knob to select the display to

"SU."

r Press and hold the [SCAN] key for 2 second while

press and holding the [FUNC] key. "SQL SET"

will appears on the display. Sounds a beep.

SQL Level Adjustment

NFM mode:

r Connect the RF Signal Generator to ANT jack. r Set the receiver to 100.050 MHz, NFM mode. r Press the [SCAN] key. "SQL" will appear on the

display.

r Tune the SSG to 100.050 MHz with ±3.5 kHz

deviation @1 kHz tone modulation, and set the

output level to -12 dBµ.

r Press the [BND(p)] key while press and holding

[FUNC] key. "SQL SL" will appear on the display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

r Increase the SSG output level to 2 dBµ. r Press the [SCAN] key while press and holding

[FUNC] key. "SQL TI" will appear on the display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

r Press the [MODE] key while press and holding

[FUNC] key. "SQL CR" will appear on the

display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

WFM mode:

r Set the receiver to 100.050 MHz, WFM mode. r Press the [SCAN] key. "SQL" will appear on the

display.

r Tune the SSG to 100.050 MHz with ±75 kHz

deviation @1 kHz tone modulation, and set the

output level to 2 dBµ.

r Press the [BND(p)] key while press and holding

[FUNC] key. "SQL SL" will appear on the display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

r Increase the SSG output level to 15 dBµ. r Press the [SCAN] key while press and holding

[FUNC] key. "SQL TI" will appear on the display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

r Press the [MODE] key while press and holding

[FUNC] key. "SQL CR" will appear on the

display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

AM mode:

r Set the receiver to 1.050 MHz, AM mode. r Press the [SCAN] key. "SQL" will appear on the

display.

r Tune the SSG to 1.050 MHz with 30%

modulation @1 kHz tone, and set the output level

to -5 dBµ.

r Press the [BND(p)] key while press and holding

[FUNC] key. "SQL SL" will appear on the display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

r Increase the SSG output level to 8 dBµ. r Press the [SCAN] key while press and holding

[FUNC] key. "SQL TI" will appear on the display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

r Press the [MODE] key while press and holding

[FUNC] key. "SQL CR" will appear on the

display.

r Press the [V/M] key while press and holding

[FUNC] key. Sounds a beep.

S-Meter Adjustment

NFM mode:

r Connect the RF Signal Generator to ANT jack. r Set the receiver to 100.050 MHz, NFM mode. r Press the [BND(p)]. "S M ET" will appear on the

display.

r Tune the SSG to 100.050 MHz with ±3.5 kHz

deviation @1 kHz tone modulation, and set the

output level to 20 dBµ.

+ 23 hidden pages

Yaesu VR-120D, VR-12D Technical Supplement

Specifications and Main Features

Frequently Asked Questions

User Manual