Yaesu FT-1900R, Technical Supplement

1

Introduction

This manual provides technical information necessary for servicing the FT-1900R 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
components (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.

©2009 VERTEX STANDARD CO., LTD.

EH023N91A

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

FM TRANSCEIVER

FT-1900R

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 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

VERTEX STANDARD 

(

AUSTRALIA

)

 PTY., LTD.

Normanby Business Park, Unit 14/45 Normanby Road

Notting Hill 3168, Victoria, Australia

Important Note

The 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 appara-
tus. 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.