Yaesu FT-857 Technical Supplement

FT-857/-857D
Technical Supplement
©
2007 VERTEX STANDARD CO., LTD.
Introduction
This manual provides technical information necessary for servicing the FT-857/-857D HF/VHF/UHF Ultra-Compact Trans-
ceiver.
Servicing this equipment requires expertise in handling surface-mount chip components. Attempts by non-qualified per-
sons 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.
Specifications .................................................. 2
Exploded View & Miscellaneous Parts ...... 5
Connection Diagram ...................................... 7
Block Diagram ................................................. 8
Circuit Description ........................................ 9
Alignment ...................................................... 12
EH007M90C
Contents
Board Unit
MAIN Unit ................................................................. 25
PLL Unit ..................................................................... 63
PA Unit ....................................................................... 75
PANEL Unit ............................................................... 93
REF Unit ..................................................................... 99
PHONE-JACK Unit ................................................. 100
VR Unit ..................................................................... 101
CONNECTOR Unit ................................................. 102
DSP-2 Unit (FT-857 Option) .................................. 103
TCXO-9 Unit (Option) ............................................ 106
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
VERTEX STANDARD ( AUSTRALIA ) PTY., LTD.
Normanby Business Park, Unit 14/45 Normanby Road
Notting Hill 3168, Victoria, Australia
(Schematics, Layouts & Parts)
1