Yaesu FT-1802M Service Manual

FM TRANSCEIVER

FT-1802M

Technical Supplement

VERTEX STANDARD CO., LTD.

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

VERTEX STANDARD

US Headquarters

10900 Walker Street, Cypress, CA 90630, 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

Introduction

This manual provides technical information necessary for servicing the FT-1802M FM Transceiver.

Servicing this equipment requires expertise in handling surface-mount chip components. Attempts by non- qualified persons to service this equipment may result in permanent damage not covered by the warranty, and may be illegal in some countries.

Two PCB layout diagrams are provided for each double-sided circuit board in the Transceiver. Each side of is referred to by the type of the majority of components installed on that side (“leaded” or “chip-only”). In most cases one side has only chip components, and the other has either a mixture of both chip and leaded compo- nents (trimmers, coils, electrolytic capacitors, ICs, etc.), or leaded components only.

While we believe the technical information in this manual to be 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.

Contents

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

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

Block Diagram .................................................. 5

Connection Diagram......................................... 6

Circuit Description ........................................... 7

Alignment .......................................................... 9

Board Unit (

MAIN Unit Circuit Diagram ................................. 13

MAIN Unit Parts Layout .......................................15

MAIN Unit Parts List ............................................ 17

CNTL Unit Circuit Diagram ................................. 27

CNTL Parts Layout ............................................... 28

CNTL Parts List .................................................... 29

Schematics, Layouts & Parts

)

Specifications

General

Frequency Range: Tx 144 - 146 MHz or 144 - 148 MHz

Rx 144 - 146 MHz or 136 - 174 MHz

Channel Step: 5/10/12.5/15/20/25/50/100 kHz Standard Repeater Shift: ±600 kHz Frequency Stability: Better than ±10 ppm [–4 °F to +140 °F (–20 °C to +60 °C)] Modes of Emission: F2/F3 Antenna Impedance: 50 Ohms, unbalanced Supply voltage: 13.8 V DC ±15%, negative ground Current Consumption (typical): Rx: less than 0.7 A, less than 0.3 A (squelched)

Tx: 10 A (50 W) /7 A (25 W) /5 A (10 W) /4 A (5 W)

Operating Temperature Range: –4° F to +140° F (–20° C to +60° C) Case Size (WxHxD): 5.5” x 1.6” x 5.7” (140 x 40 x 146 mm) (w/o knobs) Weight (Approx.): 2.6 lb (1.2 kg)

Transmitter

Output Power: 50 W/25 W/10 W/5 W Modulation Type: Variable Reactance Maximum Deviation: ±5 kHz/±2.5 kHz Spurious Radiation: Better than –60 dB Microphone Impedance: 2000 Ohms

Receiver

Circuit Type: Double Conversion Superheterodyne Ifs: 21.7 MHz & 450 kHz Sensitivity (for 12dB SINAD): Better than 0.2 µV Selectivity (–6/–60dB): 12 kHz/28 kHz IF Rejection: Better than 70 dB Image Rejection: Better than 70 dB Maximum AF Output: 3 W into 4 Ohms @10 % THD

Specifications subject to change without notice or obligation. Specifications guaranteed only within Amateur band. Frequency ranges and functions will vary according to transceiver version; check with your dealer.

Exploded View & Miscellaneous Parts

VXSTD P/N

AAA43X001 T9021715 T9022815 Q0000081 Q0000075 D6000055 CB0297000

REF.

VXSTD P/N

U03310002



U24112002



U24308002



U36206007



U51320007



ACCESSORIES

DESCRIPTION

MICROPHONE (MH-48A6J DC CABLE (FT-1802M DC CABLE (FT-1802E SPARE FUSE (15 A: FT-1802M SPARE FUSE (15 A: FT-1802E BRACKET (MMB-36 SCREW SET

DESCRIPTION

SEMS SCREW ASM3X10NI TAPTITE SCREW M2X12NI TAPTITE SCREW M3X8NI TAPTITE SCREW M2.6X6B HEXA SOCKET BOLT M3X20B

)



CP8422001 CASE ASSY w/SP NET: S8002087

T9206438A WIRE ASSY



M4090178 SPEAKER

S8002118 (2 pcs) CUSHION

S8002063 CAP-SP



T9206876 (FT-1802M) T9206955 (FT-1802E) WIRE ASSY

)



QTY.

4 4

9 3







G1094220 RA60H1317M1



MAIN UNIT

Non-designated parts are available only as part of a designated assembly.

RA0754500 INTER CONNECTOR

G6090169

RA0753800 RUBBER KNOB

RA0754100 KNOB (VOL/CQL)

LCD



RA0754200 ENCODER KNOB

CNTL UNIT

RA0753600 FRONT PANEL

T9207248 WIRE ASSY

RA0754600 DIFFUSER



RA0754300 REFLECTOR



RA0754400 GROUND PLATE



P1091172 CONNECTOR

RA0753400 CHASSIS

Note

Block Diagram

Connection Diagram

Circuit Description

Receive Signal Path

Incoming RF signal is from the antenna jack is de- livered to the Main Unit and passed through the low- pass filter network consisting capacitors C1213, C1236, C1239, & C1241 and coils L1017, L1018, & L1019, antenna switching diode D1020 and D1028 (both RLS135), and varactor-tuned band-pass filter consisting of capacitors C1248, C1249, C1250, C1251, C1252, & C1268, coils L1020, L1021, & L1024, and diodes D1024 and D1025 (both HVC350B), before delivery to the RF amplifier Q1045 (3SK296ZQ). The amplified RF signal is passed through the another varactor-tuned band-pass filter consisting of capac- itors C1198, 1199, 1200, & 1218, coils L1012 and L1015, and diodes D1017 and D1021 (both HVC350B), then applied to the 1st mixer Q1037 (3SK296ZQ) along with the first local signal from the PLL circuit.

The first local signal is generated between 114.3 MHz and 152.3 MHz by the VCO, which consists of Q1009 (2SC5231) and varactor diode D1002 (HVC350B) according to the receiving frequency.

IF and Audio Circuits

The 21.7 MHz first IF signal is applied to the mono- lithic crystal filters XF1001 and XF1002 which strip away unwanted mixer products, and the IF signal is applied to the first IF amplifier Q1032 (2SC4400). The amplified first IF signal is then delivered to the FM IF subsystem IC Q1028 (NJM2591V), which con- tains the second mixer, limiter amplifier, noise am- plifier, and FM detector.

The audio signal passes through a band-pass filter consisting of Q1046 and Q1047 (both 2SC4154), and the audio mute gate Q1039 (2SJ347), to the audio VR which adjusts the audio sensitivity to compen- sate for audio level variations. The adjusted audio signal is delivered to the audio amplifier Q1035 (LA4425A) which provides up to 3 Watts, to the ex- ternal speaker jack or a 4-Ohm loudspeaker.

Squelch Control

When no carrier received, the noise signal from Q1028 (NJM2591V) is amplified by Q1051 (2SC4617), and is detected by D1011 and D1013 (both DA221). The resulting DC voltage passes through the SQL knob to main CPU Q2002 (HD64F2266TF13). While no carrier is received, main CPU Q2002 (HD64F2266TF13) control Q1048 (CD4094BPWR), thus, audio mute gate Q1034 (2SJ364) and Q1039 (2SJ347) turns “OFF” to dis- able the audio output from the speaker.

Transmit Signal Path

The speech signal from the microphone is amplified by Q1049 (LA2902PWR). The amplified speech sig- nal is subjected to the low-pass filter network Q1049 (LA2902PWR) to deviation controlled by Q1043 (M62364FP).

The adjusted speech signal from Q1043 (M62364FP) is delivered to VCO Q1009 (2SC5231) which fre- quency modulates the transmitting VCO made up of D1004 (HSC277).

The second local signal is generated by 21.25 MHz crystal X1001, produces the 450 kHz second IF sig- nal when mixed with first IF signal within Q1028 (NJM2591V).

The 450 kHz second IF signal is applied to the ce- ramic filter CF1001 (for Narrow FM) or CF1002 (for Wide FM) which strip away unwanted mixer prod- ucts to the ceramic discriminator CD1001 which re- moves any amplitude variations in the 450 kHz IF signal before detection of speech.

The detected audio from the Q1028 (NJM2591V) passes through the de-emphasis circuit consisting of resistors R1082 & R1113, and capacitors C1120 & C1122, to the audio mute gate Q1034 (2SJ364)

The modulated transmit signal passes through buff- er amplifier Q1010 and Q1023 (both 2SC5374).

The transmit signal applied to the drive amplifier Q1026 (2SC5226), then finally amplified by power amplifier module Q1030 (RA60H1317M) up to 50 Watts. The APC circuit controls the Q1030 (RA60H1317M) power amplifier’s gain.

The 50 Watts RF signal passes through low-pass fil- ter network consisting of Capacitors C1210 and C1211 and coil L1013, antenna switch D1018 and D1019 (both XB15A709), and another low-pass fil- ter network consisting capacitors C1213, C1236, C1239, & C1241 and coils L1017, L1018, & L1019, and then deliver to the ANT jack.

Circuit Description

TX APC Circuit

A portion of the power amplifier module output is rectified by D1022 (1SS321), then delivered to APC Q1038 (LM2904PWR), as a DC voltage which is pro- portional to the output level of the power amplifier module.

The APC Q1038 (LM2904PWR) is compared the rec- tified DC voltage from the power amplifier module and the reference voltage from the main CPU Q2002 (HD64F2266TF13), to produce a control voltage, which regulates supply voltage to the power ampli- fier module Q1030 (RA60H1317M), so as to main- tain stable output power under varying antenna loading condition.

PLL

A portion of the output from the VCO Q1009 (2SC5231) passes through the buffer amplifier Q1010 and Q1017 (both 2SC5374), then delivered to the programmable divider section of the PLL IC Q1011 (MB15A01PFV1), which divided according

to the frequency dividing data that is associated with the setting frequency input from the main CPU Q2002 (HD64F2266TF13). It is then sent to the phase comparator section of the PLL IC Q1011 (MB15A01PFV1).

The 21.25 MHz frequency of the reference oscillator circuit made up of X1001 is divided by the reference frequency divider section of Q1011 (MB15A01PFV1) into 4250 or 3400 parts to become 5 kHz or 6.25 kHz comparative reference frequencies, which are uti- lized by the phase comparator section of Q1011 (MB15A01PFV1).

The phase comparator section of Q1011 (MB15A01PFV1) compares the phase between the frequency-divided oscillation frequency of the VCO circuit and comparative frequency and its output is a pulse corresponding to the phase difference. This pulse is integrated by the charge pump and loop fil- ter into a control voltage (VCV) to control the oscil- lation frequency of the VCO Q1009 (2SC5231).

Alignment

Introduction

The FT-1802M is carefully aligned at the factory for the specified performance across the amateur band. Realignment should therefore not be necessary ex- cept in the event of a component failure. Only an authorized Vertex Standard representative should perform all component replacement and service, or the warranty policy may be void.

The following procedures cover the adjustments that are not normally required once the transceiver has left the factory. However, if damage occurs and some parts subsequently are replaced, realignment may be required. If a sudden problem occurs during nor- mal 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. If a fault is sus- pected, contact the dealer from whom the transceiver was purchased for instructions regarding repair. Authorized Vertex Standard service technicians re- align all circuits and make complete performance checks to ensure compliance with factory specifica- tions after replacing any faulty components.

Those who do undertake any of the following align- ments are cautioned to proceed at their own risk. Problems caused by unauthorized attempts at re- alignment are not covered by the warranty policy. Also, Vertex Standard reserves the right to change circuits and alignment procedures in the interest of improved performance, without notifying owners.

Required Test Equipment

The following test equipment (and familiarity with its use) is necessary for complete realignment. Cor- rection of problems caused by misalignment result- ing from use of improper test equipment is not cov- ered under the warranty policy. While most steps do not require all of the equipment listed, the inter- actions 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 pre- sented.  RF Signal Generator with calibrated output level

at 200 MHz

 Deviation Meter (linear detector)  In-line Wattmeter with 5% accuracy at 200 MHz  50-Ohm 50-W RF Dummy Load  8-Ohm AF Dummy Load  Regulated DC Power Supply adjustable from 6

to 15 VDC, 10A

 Frequency Counter: 0.2-ppm accuracy at 200 MHz  AF Signal Generator  AC Voltmeter  DC Voltmeter: high impedance  VHF Sampling Coupler  SINAD Meter

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 realignment determined to be absolutely necessary.

Alignment

Alignment Preparation & Precautions

A 50-Ohm RF load and in-line wattmeter must be connected to the antenna jack in all procedures that call for transmission; alignment is not possible with an antenna. After completing one step, read the next step to see if the same test equipment is required. If not, remove the test equipment (except dummy load and wattmeter, if connected) before proceeding.

Correct alignment requires that the ambient tem- perature be the same as that of the transceiver and test equipment, and that this temperature be held constant between 68 °F ~ 86 °F (20 °C ~ 30 °C). When the transceiver is brought into the shop from hot or cold air, it should be allowed some time to come to room temperature before alignment. Whenever pos- sible, 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.

Note: Signal levels in dB referred to in the alignment procedure are based on 0dBµ = 0.5µV.

Test Setup

Set up the test equipment as shown below for trans- ceiver alignment.

Entering the Alignment Mode

Alignment of the FT-1802M is performed using a front panel software-based procedure. To perform alignment of the transceiver, it must first be placed in the “Alignment Mode,” in which the adjustments will be made and then stored into memory.

To enter the Alignment mode, press and hold in the [

REV(DW)] and [D/MR(MW)] keys while turning the

radio on. Once the radio is on, release these two key. The transceiver is now in the “Alignment Mode.”

PLL Reference Frequency

 Rotate the DIAL knob to set the alignment param-

eter to “148.000 rF.”

 Press the [D/MR(MW)] key to enable adjustment

of the “PLL Reference Frequency.”

 Press the PTT switch to activate the transmitter,

adjust the DIAL knob so that the counter fre- quency reading is 148.000 MHz (±100 Hz).

 Press the [D/MR(MW)] key.

RF Front-end Tuning

 Inject a 145.100 MHz signal at a level of –10 dBµ

(with 1 kHz modulation @±3.5 kHz deviation) from the RF signal generator.

 Rotate the DIAL knob to set the alignment param-

eter to “145.100 tn.”

 Press the [D/MR(MW)] key to enable adjustment

of the “RF Front-end Tuning.”

 Adjust the DIAL knob so that the maximum

SINAD.

 Press the [D/MR(MW)] key.

50-Ohm

Dummy Load

Inline

Wattmeter

Frequency

Counter

Signal Generator

RF Sampling

Coupler

ANT

Signal Generator

TEST EQUIPMENT SETUP

FT-1802M

MIC

DC INPUT

EXT SP

Signal Generator

SINAD MeterDeviation Meter

GND +8V

MIC INPUT

PTT/CLONE

MIC SW1

MIC SW2

Alignment

Squelch Threshold Level

 Inject a 145.100 MHz signal at a level of –14 dBµ

(with 1 kHz modulation @±3.5 kHz deviation) from the RF signal generator.

 Rotate the SQL knob to the 10-o’clocl position.  Rotate the DIAL knob to set the alignment param-

eter to “145.100 tL.”

 Press the [D/MR(MW)] key to enable adjustment

of the “Squelch Threshold Level.”

 Press the [D/MR(MW)] key three times.  Press the [D/MR(MW)] key.

S-meter Level (S-1)

 Inject a 145.100 MHz signal at a level of –5 dBµ

(with 1 kHz modulation @±3.5 kHz deviation) from the RF signal generator.

 Rotate the DIAL knob to set the alignment param-

eter to “145.100 S1.”

 Press the [D/MR(MW)] key to enable adjustment

of the “S-meter Level (S-1).”

 Press the [D/MR(MW)] key three times.  Press the [D/MR(MW)] key.

S-meter Level (S-9)

 Inject a 145.100 MHz signal at a level of +20 dBµ

(with 1 kHz modulation @±3.5 kHz deviation) from the RF signal generator.

 Rotate the DIAL knob to set the alignment param-

eter to “145.100 S9.”

 Press the [D/MR(MW)] key to enable adjustment

of the “S-meter Level (S-9).”

 Press the [D/MR(MW)] key three times.  Press the [D/MR(MW)] key.

TX Power (High)

 Rotate the DIAL knob to set the alignment param-

eter to “145.000 HP.”

 Press the [D/MR(MW)] key to enable adjustment

of the “TX Power (High).”

 Press the PTT switch to activate the transmitter,

adjust the DIAL knob so that the RF Power Meter reading is 50 W (±2.0W).

 Press the [D/MR(MW)] key.

TX Power (Low 3)

 Rotate the DIAL knob to set the alignment param-

eter to “145.000 L3.”

 Press the [D/MR(MW)] key to enable adjustment

of the “TX Power (Low 3).”

 Press the PTT switch to activate the transmitter,

adjust the DIAL knob so that the RF Power Meter reading is 25 W (±1.5 W).

 Press the [D/MR(MW)] key.

TX Power (Low 2)

 Rotate the DIAL knob to set the alignment param-

eter to “145.000 L2.”

 Press the [D/MR(MW)] key to enable adjustment

of the “TX Power (Low 2).”

 Press the PTT switch to activate the transmitter,

adjust the DIAL knob so that the RF Power Meter reading is 10 W (±1.0 W).

 Press the [D/MR(MW)] key.

TX Power (Low 1)

 Rotate the DIAL knob to set the alignment param-

eter to “145.000 L1.”

 Press the [D/MR(MW)] key to enable adjustment

of the “TX Power (Low 1).”

 Press the PTT switch to activate the transmitter,

adjust the DIAL knob so that the RF Power Meter reading is 5 W (±0.5 W).

 Press the [D/MR(MW)] key.

TX Deviation

 Inject a 1 kHz, 50 mV signal from the Audio Gen-

erator.

 Rotate the DIAL knob to set the alignment param-

eter to “145.000 dU.”

 Press the [D/MR(MW)] key to enable adjustment

of the “TX Deviation.”

 Press the PTT switch to activate the transmitter,

adjust the DIAL knob so that the Deviation Meter reading is 4.2 kHz (±0.1 kHz) (EXP version: 4.5 kHz ± 0.1 kHz).

 Press the [D/MR(MW)] key.

+ 23 hidden pages

Yaesu FT-1802M Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Introduction

Specifications

Exploded View & Miscellaneous Parts

Block Diagram

Connection Diagram

Circuit Description

Receive Signal Path

IF and Audio Circuits

Squelch Control

Transmit Signal Path

TX APC Circuit

Alignment

Introduction

Required Test Equipment

Alignment Preparation & Precautions

Test Setup

Entering the Alignment Mode

PLL Reference Frequency

RF Front-end Tuning

Squelch Threshold Level

S-meter Level (S-1)

S-meter Level (S-9)

TX Power (High)

TX Power (Low 3)

TX Power (Low 2)

TX Power (Low 1)

TX Deviation