Board Unit (Schematics, Layouts & Parts)
HF/50MHz TRANSCEIVER
FT-891
Introduction
This manual provides the technical information necessary
for servicing the FT-891 HF/50MHz TRANSCEIVER.
Servicing this equipment requires expertise in hand
-
ing 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 provided for each double-
sided board in this transceiver. Each side of the board
is referred to by the type of the majority of components
installed on that side ("Side A" or "Side B"). 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 information in this manual to be
correct, YAESU 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.
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 com
-
position may be used.
Caution
Risk of explosion if battery is replaced by an incorrect type. Dispose of used batteries according to the instructions.
Contents
Technical Supplement
EH065H90D
©2017 YAESU MUSEN CO., LTD.
Summary of Contents for FT-891
Page 7: ...BLOCK DIAGRAM 1 FT 891 Technical Supplement Block Diagram...
Page 8: ...CONNECTION DIAGRAM 1 FT 891 Technical Supplement Connection Diagram...
Page 28: ...FT 891 Technical Supplement MAIN 1 Circuit Diagram MAIN Unit Lot 1 3...
Page 30: ...FT 891 Technical Supplement MAIN 3 Parts Layout side B MAIN Unit Lot 1 3 1 2 3 4 5 a b c d e f...
Page 31: ...FT 891 Technical Supplement MAIN 4 Circuit Diagram MAIN Unit Lot 4 6...
Page 32: ...FT 891 Technical Supplement MAIN 5 MAIN Unit Lot 4 6 Parts Layout side A 1 2 3 4 5 A B C D E F...
Page 33: ...FT 891 Technical Supplement MAIN 6 MAIN Unit Lot 4 6 Parts Layout side B 1 2 3 4 5 a b c d e f...
Page 34: ...FT 891 Technical Supplement MAIN 7 Circuit Diagram MAIN Unit Lot 7 10...
Page 37: ...FT 891 Technical Supplement MAIN 10 Circuit Diagram MAIN Unit Lot 11...
Page 38: ...FT 891 Technical Supplement MAIN 11 MAIN Unit Lot 11 Parts Layout side A 1 2 3 4 5 A B C D E F...
Page 39: ...FT 891 Technical Supplement MAIN 12 MAIN Unit Lot 11 Parts Layout side B 1 2 3 4 5 a b c d e f...
Page 66: ...FT 891 Technical Supplement LOCAL 1 Circuit Diagram LOCAL Unit...
Page 67: ...FT 891 Technical Supplement LOCAL 2 Parts Layout LOCAL Unit side A side B 1 2 A B 1 2 a b...
Page 71: ...FT 891 Technical Supplement PA 1 Circuit Diagram PA Unit...
Page 72: ...FT 891 Technical Supplement PA 2 Parts Layout side A PA Unit 1 2 3 4 5 A B C D E...
Page 73: ...FT 891 Technical Supplement PA 3 Parts Layout side B PA Unit 1 2 3 4 5 a b c d e...
Page 81: ...FT 891 Technical Supplement DSP 1 Circuit Diagram DSP Unit Lot 1 10...
Page 83: ...FT 891 Technical Supplement DSP 3 Circuit Diagram DSP Unit Lot 11...
Page 89: ...FT 891 Technical Supplement PANEL 1 Circuit Diagram PANEL Unit...
Page 96: ...SW B 1 SW B Unit Circuit Diagram Parts Layout FT 891 Technical Supplement...
