Introduction This manual provides the technical information necessary for servicing the FT-991 HF/VHF/UHF ALL MODE Transceiver ervicing 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.

Introduction... 2 Operating the Character Input Screen... 2 Alphabet Input Screen... 2 Numbers and Symbols Input Screen... 2 Using the GM Function... 3 What is the GM Function?... 3 Basic Methods to Use the GM Function... 3 Displaying all the Stations where the GM Function is in Operation... 4 Displaying only Partners Registered in the GM Group... 5 Entering the Location Information Manually... 6 Registering Groups and Group Members... 7 Creating a New Group... 7 Registering the Group Members... 8 Registering from the Group List Summary... 8 Manual Registration... 9 Changing the Group Name... 11 Changing the Name (call sign) of a Group Member... 13 Deleting a Group... 15 Deleting a Group Member... 16 Set-up Menu for the GM Function... 17 Set-up Menu List for the GM Function... 17 Using the Menu for the GM Function... 17 Specific ID Display by Transceiver 17 Switching the Information of the Other Stations... 18 Setting the Distance Unit... 19