Yaesu FT-1807M - User Manual

Introduction
This manual provides technical information necessary for servicing the FT-1807M 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.
©2006 VERTEX STANDARD CO., LTD. EH023U90A
Technical Supplement
Specifications ......................................................2
Exploded View & Miscellaneous Parts............3
Block Diagram....................................................5
Connection Diagram ..........................................6
Circuit Description.............................................7
Alignment............................................................9
Contents
Board Unit ( Schematics, Layouts & Parts )
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
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
FM TRANSCEIVER
FT-1807M
Important Note
This transceiver was assembled using Pb (lead) free solder, based on the RoHS specification.
Only lead-free solder (Alloy Composition: Sn-3.0Ag-0.5Cu) should be used for repairs performed on
this apparatus. The solder stated above utilizes the alloy composition required for compliance with the
lead-free specification, and any solder with the above alloy composition may be used.

Summary

FT-1807 M Specifications

Transmitter and Receiver Performance

Circuit Operation Details

Receive Signal Path Description

Traces RF signal from antenna through filtering, amplification, and detection.

IF and Audio Signal Processing

Explains intermediate frequency stages, audio amplification, and de-emphasis.

Squelch Control and Transmit Path

Service Alignment Procedures

Required Test Equipment for Alignment

Lists essential test gear needed for accurate calibration and performance tuning.

Alignment Mode and Initial Setup

Preparation and Entering Alignment Mode

Covers precautions and the procedure to access the alignment software menu.

PLL and RF Front-end Tuning

Alignment Parameter Adjustments

Squelch, S-meter, and Power Output Alignment

Details calibration steps for squelch level, S-meter, and various TX power outputs.

TX Deviation Calibration

Explains how to adjust frequency deviation for optimal FM transmission quality.

MAIN Unit Circuit Schematic

MAIN Unit Detailed Circuit Diagram

The complete schematic diagram for the MAIN unit, showing all components and connections.

MAIN Unit Component List

Transistors and Integrated Circuits

CNTL Unit Circuit Schematic

CNTL Unit Detailed Circuit Diagram

The complete schematic diagram for the CNTL unit, detailing its circuitry.

CNTL Unit Component List

Yaesu FT-1807M Specifications

General

Frequency Range	144-148 MHz
Mode	FM
Output Power	50W
Channels	200
Supply Voltage	13.8V DC
Type	Mobile