Yaesu FT-7900R Technical Supplement

Dual Band FM Transceiver
FT-7900R/E
Technical Supplement
©
2011 VERTEX STANDARD CO., LTD.
This manual provides technical information necessary for servicing the FT-7900R/E 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 thr board 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 dam-
age 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.
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 specifica-
tion, and any solder with the above alloy composition may be used.
Specifications ................................................ A-1
Exploded View & Miscellaneous Parts ..... B-1
Block Diagram ................................................ C-1
Circuit Description ....................................... D-1
Alignment ....................................................... E-1
FT-7900R/E Technical Supplement
EH016M93B

Important Note

Board Unit (Schematics, Layouts & Parts)
MAIN Unit................................................. F-1
Panel Unit ............................................. G-1
CH Unit ..................................................... H-1
VERTEX STANDARD CO., LTD.
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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.
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Kwun Tong, Kowloon, Hong Kong
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