Yaesu FT-991 User manual

HF/VHF/UHF All Mode TrAnsceiVer
FT-991
operATing MAnUAl
YAESU MUSEN CO., LTD.
Tennozu Parkside Building
2-5-8 Higashi-Shinagawa, Shinagawa-ku, Tokyo 140-0002 Japan
YAESU USA
6125 Phyllis Drive, Cypress, CA 90630, U.S.A.
YAESU UK
Unit 12, Sun Valley Business Park, Winnall Close
Winchester, Hampshire, SO23 0LB, U.K.

About this MAnuAl . . .
The FT-991 is a leading-edge transceiver with a number of new and exciting features, some of which may be unfamiliar
to you. In order to gain the most enjoyment and operating efciency from your FT-991, we recommend that you read
this manual in its entirety, and keep it handy for reference as you explore the many capabilities of your new transceiver.
Before using your FT-991, be sure to read and follow the instructions in the “Before You Begin” section of this manual.
About TFT Displays
FT-991 utilizes a TFT liquid-crystal display.
• Although TFT liquid-crystal displays are made using very precise technology, they are prone to develop
dead pixels (dark dot) or pixels that are always on (bright dot). Please understand that such phenomena
do not constitute product defects or malfunctions. Rather, this phenomena occurs due to limitations in the
manufacturing technology with respect to TFT liquid-crystal displays.
• Depending on the viewing angle, unevenness in color or brightness may occur. Please note that any uneven-
ness observed is inherent to the construction of TFT liquid crystal displays and therefore does not constitute
a product defect or malfunction.
• If your TFT liquid-crystal display becomes dirty, please use a dry soft cloth or tissue to wipe the display
clean. Use of glass cleaner, household cleaners, organic solvents, alcohol, abrasives, and/or like substance
may damage the TFT liquid-crystal display.

Page 1
FT-991 OperaTing Manual
General Description
Built-in high-brightness TFT full-color
display with touch-panel functionality
The FT-991 is equipped with a 3.5 inch full-color TFT
display. Functions, including the receiving band, the noise
and signal interference reduction tools are graphically
displayed. Even while performing rigorous operations,
during DX pditions or contests, the operator may instantly
grasp the status of each function.
Equipped with C4FM digital mode
This transceiver C4FM mode provides good error cor-
rection performance, and supports the V/D mode (voice/
data simultaneous transmission mode) which makes the
transceiver suitable for mobile communication, and the
Voice FR mode (voice full rate mode) which allows the
transceiver to transmit high quality digital audio. The AMS
function recognizes the contacting stations transmission
method and automatically switches the transceiver to the
same C4FM digital or analog (FM) communications mode
as the received signal.
GM (Group Monitor) function allows
registering frequently communicating
stations to a memory group. The group
members may then automatically
exchange (send/receive) station location
information.
The transceiver automatically checks the channel fre-
quency for registered member stations that are within com-
municating range. The distance and direction information
of the call sign members of the group may be shown on
the TFT display.
Comes equipped with two types of
roong lters
This transceiver is equipped with two types of roong
lters for 3kHz and 15kHz bandwidths. These narrow band
lters are especially useful on a very crowded band during
contests, because they can dramatically attenuate powerful
out-of-band signals in the rst IF stage and reduce their
impact in the second stage to further optimizing the excel-
lent dynamic range and IP3 characteristics for processing
signals ranging from faint to powerful.
Two selectable RF ampliers provide the
optimal receiver gain for each low-to high
HF band (see page 46.)
Congure the front end RF circuitry for the precise gain and
performance to suit the conditions of each HF band.Select
the IPO (Intercept Point Optimization) feature to optimize
the proximal multi-signal and mutual modulation character-
istics in order to minimize the effects of powerful broadcast
stations, especially in the low-band so that even the faintest
signals can be received. When higher gain is advantageous,
select the single low noise RF amplier AMP1. In the high
bands, adding AMP2 provides maximum useful gain.
High stability built-in TCXO
The 30.225 MHz standard oscillator provides exceptional
frequency stability. It is temperature compensated and
boasts an enhanced ±0.5 ppm stability from −10°C to
+50°C.
WIDTH feature and continuously variable
bandwidth SHIFT feature. Optimal wide to
narrow bandwidth switching (see pages
49, 50.)
The SHIFT feature, can eliminate interference in one side
of the passband. The WIDTH feature allows the bandwidth
to be narrowed by rotating the WIDTH knob. The moment
weak signals disappear due to interfering signals (includ-
ing pile-ups), you can eliminate the interfering signals and
extract only the desired signal, thanks to the unique DSP
sharp ltering characteristic.
CONTOUR feature is renowned for
effective noise control (see page 48.)
Rather than using the DSP extremely sharp attenuation
characteristics, the CONTOUR circuit provides gentle
shaping of the DSP passband lter and can thus attenuate
or peak bandwidth components in segments. The interfer-
ing signal can be naturally shaped without having part of
the signal suddenly interrupted. The contour function is
very effective in making the desired signal rise out of the
interference.
DNR (Digital Noise Reduction) by DSP
digital processing (see page 54.)
The incorporated digital noise reduction circuit may be
set to the optimal working point by varying the 15 step
parameters according to the noise type.
NOTCH feature that significantly
eliminates unwanted beat signals; and
DNF feature that instantly attenuates
multiple beat signals (see page 54.)
When interfering beat signals are present in the receiver
passband, the IF NOTCH feature can signicantly elimi-
nate a part of the passband and remove the beat signal.
Moreover, the function is equipped with an Automatic
Tracking System DNF (Digital Notch Filter) that can
be engaged by DSP when there are multiple interfering
signals, even when the frequency is changing.
Reliable High-output Final Amplifier
Stage
In the HF/50MHz frequency range, a pair of RD100HHF1
transistors in a push-pull RF amplier arrangement deliv-
ers 100 watts of low-distortion, high-quality transmitter
power. The nal amplier for the 144 MHz/430 MHz
bands uses the high-output RDH70HUF2 device, provid-
ing ample output power of 50 watts.

Page 2 FT-991 OperaTing Manual
General Description
Microphone Amplifier that includes
Parametric Equalizer (see page 63.)
The microphone amplier equalizer feature is equipped
with a three-stage parametric equalizer that can alter the
Low, Mid, and High frequencies of the audio separately;
this feature permits the bandwidth and gain for each part of
the audio spectrum to be precisely adjusted independently.
High Speed Spectrum Scope (see page
40.)
The spectrum scope function provides a visual display of
the intensity and distribution of signals across the band .
When using the ASC (Automatic Spectrum-Scope Con-
trol) mode, the scope spectrum is automatically swept in
response to the movement of the main tuning dial; the
scanned spectrum signal distribution can be observed in
real-time.
High speed antenna tuner (see page
61.)
The transceiver is equipped with the relay switching high
speed digital tuner which supports 1.8 MHz to 50 MHz.
The large 100-channel tuning data memory allows im-
mediate recall of the optimum matching conditions for
previously tuned frequencies.
Optional Five Channel Message Memory
(voice memory) (see page 68.)
You can use the 5 channel voice memory function which
is useful for operating in contests, etc. This voice memory
enables recording of up to 20 seconds of audio for each
message you want to send.
Custom selection (C.S) button (see page
37.)
This feature lets you select any Menu item for one-touch
access via the C.S button.

Page 3
FT-991 OperaTing Manual
table of contents
General Description ..................................................... 1
Table of Contents ......................................................... 3
Accessories & Options ................................................. 5
Supplied Accessories................................................ 5
Available Options..................................................... 6
Before You Begin.......................................................... 7
Base Station Wire Stand........................................... 7
Adjusting the Main Tuning Dial Torque .................. 7
Adjusting the Clock.................................................. 8
Inputting the Call Sign ............................................. 9
Resetting the Microprocessor................................. 10
Antenna Considerations ......................................... 11
About Coaxial Cable .............................................. 11
Grounding............................................................... 12
Connection of Antenna and Power Cables............. 13
Installation and Interconnections............................. 14
Connection of Microphone, Headphone and
Remote Control Keypad......................................... 14
Key, Keyer, and Computer-Driven Keying
Interconnections ..................................................... 15
VL-1000 Linear Amplier Interconnections.......... 16
Plug/Connector Pinout Diagrams........................... 17
Front Panel Controls & Switches ............................. 18
About the Display....................................................... 22
TFT Liquid Crystal Display ................................... 22
LED Indicators ....................................................... 24
Rear Panel................................................................... 25
MH-31A8J Microphone Switches............................. 27
Optional FH-2 Remote Control Switches ................ 28
Optional MH-36E8J Microphone Switches............. 29
Basic Operation: Receiving on Amateur Bands ...... 30
Operation on 60-Meter (5 MHz) Band
(U.S. and U.K. version only).................................. 33
CLAR (Clarier) Operation ................................... 34
LOCK..................................................................... 35
DIMMER ............................................................... 35
VFO COLOR ......................................................... 36
Convenience Features................................................ 37
Band Stack Operation............................................. 37
C.S (Custom Switch).............................................. 37
AMS (Automatic Mode Select) Operation............. 38
SCOPE ................................................................... 40
More Frequency Navigation Techniques ............... 42
Receiver Operation (Front End Block Diagram) ... 44
Interference Rejection ............................................... 45
ATT (Attenuator).................................................... 45
IPO (Intercept Point Optimization) ........................ 46
IF Noise Blanker (NB) Operation .......................... 47
CONTOUR Control Operation .............................. 48
IF SHIFT Operation
(SSB/CW/RTTY/PKT Modes)............................... 49
WIDTH (IF DSP Bandwidth) Tuning
(SSB/CW/RTTY/DATA Modes) ............................ 50
NARROW (NAR) One-Touch IF Filter
Selection................................................................. 52
IF NOTCH Filter Operation
(SSB/CW/RTTY/DATA/AM Modes) .................... 53
Digital NOTCH Filter (DNF) Operation................ 54
Digital Noise Reduction (DNR) Operation............ 54
Tools for Comfortable and Effective Reception ...... 55
RF Gain .................................................................. 55
Audio Peak Filter ................................................... 56
AGC (Automatic Gain Control)............................. 57
Adjustable Receiver Audio Filter........................... 58
SSB/AM Mode Transmission .................................... 59
Using the Automatic Antenna Tuner ........................ 61
ATU Operation ....................................................... 61
About ATU Operation ............................................ 62
Enhancing Transmit Signal Quality......................... 63
Parametric Microphone Equalizer
(SSB/AM/FM mode).............................................. 63
Using the Speech Processor (SSB Mode) .............. 66
Adjusting the SSB Transmitted Bandwidth
(SSB Mode)............................................................ 67
Transmitter Convenience Features .......................... 68
Voice Memory (SSB/AM modes) .......................... 68
VOX (SSB/AM/FM Modes: Automatic TX/RX
Switching using Voice Control) ............................. 70
MONITOR (SSB/AM/FM modes)......................... 72
Split Operation Using the TX Clarier .................. 73
Split-Frequency Operation ..................................... 74
CW Mode Operation ................................................. 76
Setup for Straight Key
(and Straight Key emulation) Operation ................ 76
Using the Built-in Electronic Keyer....................... 78
CW Convenience Features ........................................ 82
CW Spotting (Zero-Beating) .................................. 82
CW Delay Time Setting ......................................... 83
CW Pitch Adjustment............................................. 83
Contest Memory Keyer .......................................... 84
FM Mode Operation .................................................. 91
Basic Operation ...................................................... 91
Repeater Operation................................................. 92
Tone Squelch Operation ......................................... 94
C4FM Mode (Digital Mode) Operation ................... 95
Memory Operation .................................................... 97
Convenient Memory functions............................... 97
QMB (Quick Memory Bank) ................................. 97
Standard Memory Operation.................................. 98
Memory Groups ................................................... 104

Page 4 FT-991 OperaTing Manual
table of contents
Operation on Alaska Emergency Frequency:
5167.5 khz (U.S. Version Only) ............................... 106
VFO and Memory Scanning ................................... 107
VFO Scanning...................................................... 107
Memory Scan ....................................................... 108
PMS (Programmable Memory Scanning) ............. 109
Using the GPS Function .......................................... 110
What is GPS? ....................................................... 110
Positioning Using GPS......................................... 110
Displaying the Position Information .................... 112
Using the GM Function ........................................... 113
What is the GM Function? ................................... 113
Basic Methods to Use the GM Function .............. 113
RTTY (Radio Teletype) Operation ......................... 116
Example of Connecting RTTY Communications
Device................................................................... 116
DATA (PSK) Operation ........................................... 118
Example of Data Communications Device .......... 118
Menu Mode............................................................... 120
Installation of Optional Accessories ....................... 139
FC-40 External Automatic Antenna Tuner
(for Wire Antenna) ............................................... 139
Active-Tuning Antenna System (ATAS-120A)
Operation.............................................................. 141
Mounting Bracket MMB-90 Installation.............. 143
Specications ............................................................ 144
Index.......................................................................... 146

Page 5
FT-991 OperaTing Manual
accessories & options
Supplied AcceSSorieS
DC Power Cord Hand Microphone (MH-31A8J)Spare Fuse (25A)
Operating Manual
Warranty Card
World Map
Sticker
The illustrations above may vary slightly from the actual accessories.

Page 6 FT-991 OperaTing Manual
Accessories & options
AvAilAble OptiOns
For details, see “Installation of Optional Accessories” on page 139 or the catalog.
Ultra-High-Fidelity Desktop
Microphone
MD-200A8X
Lightweight Stereo Headphone
YH-77STA
Remote Control Keypad
FH-2
Linear Amplier/AC Power Supply
VL-1000/VP-1000
External Automatic Antenna Tuner
FC-40
Others
Hand Microphone MH-31A8J (equivalent to the supplied microphone)
DTMF Hand Microphone MH-36E8J
Desktop Microphone MD-100A8X
Active Tuning Antenna (Automatic Type) ATAS-120A
Antenna Base Kit ATBK-100
Active Tuning Antenna (Manual Type) ATAS-25
Mobile Bracket MMB-90
External Power Supply (13.8 VDC 23 A) FP-1023A (U.S.A. only)
External Power Supply (13.8 VDC 25 A) FP-1030A
VL-1000 Linear Amplier Connection Cable CT-58
Packet Interface Cable CT-39A

Page 7
FT-991 OperaTing Manual
bASe StAtion Wire StAnd
The heavy wire stand on the bottom of the transceiver allows the transceiver to be tilted upward for better viewing. Sim-
ply fold the stand forward to raise the front of the transceiver, and fold it back against the bottom case to lower the front
of the FT-991.
AdjuSting the MAin tuning diAl torque
The torque (drag) of the Main Tuning Dial knob may be adjusted according to your preferences. Rotate the skirt at the
base of the knob clockwise to reduce the drag, or counter-clockwise to increase the drag.
Skirt
before You beGin

Page 8 FT-991 OperaTing Manual
before You beGin
AdjuSting the clock
Use the following procedure to adjust the clock shown at the top right of the LCD display.
1. Press and hold the MENU(SETUP) button.
2. Touch [TIME/DATE]on the LCD.
MENU(SETUP) button
LCD
3. Enter the present time with the number keys on the
LCD, then touch [ENT].
4. Touch
[DATE]on the LCD to switch the screen.
5. Enter month, day, and year with the number keys on
the LCD, then touch [ENT].
6. Touch
[BACK]on the LCD to return to the setup
mode display.
7. Press the MENU(SETUP) button to return to the
radio operation display.
[TIME]
Sets the time display. Touching this button toggles be-
tween UTC (Coordinated Universal Time) and the local
time. When UTC is displayed, “Z” appears on the right
side of the time.
[DATE]
Sets the date display. Touching this button toggles be-
tween MM/DD/YYYY and YYYY/MM/DD.
[DST]
Touching this button switches daylight saving time be-
tween ON and OFF. When daylight saving time is set to
on, “D” appears on the right side of the time.

Page 9
FT-991 OperaTing Manual
inputting the cAll Sign
When turning on the power for the rst time after purchase, or after resetting the transceiver, enter your own call sign.
The call sign will be displayed on the start screen when turning on the power and will be used to identify the station
when sending messages during digital communication.
1. Press and hold the MENU(SETUP) button.
2. Touch [MY CALL]on the LCD.
MENU(SETUP) button
LCD
Advice:
The time duration of the initial call sign start up
screen display may be changed from the Menu item
“005 MY CALL INDICATION”.
3. Touch a character key. The touched character will be
displayed at the top of the screen. Enter each charac-
ter of your call sign.
Advice:
 Up to 10 characters (letters, numbers, and sym-
bols) can be entered.
4. Touch
[ENT]on the LCD. The call sign setting is
completed and the display will switch to the frequen-
cy display screen.
before You beGin

Page 10 FT-991 OperaTing Manual
before You beGin
reSetting the MicroproceSSor
reSetting MeMorieS (only)
Use this procedure to reset (clear) the previously stored
Memory channels, without affecting any conguration
changes you may have made to the Menu settings.
1. Press the front panel ON/OFF switch to turn the
transceiver off.
2. While holding the A

Mbutton in, press and hold
in the front panel ON/OFF switch to turn the trans-
ceiver on. Once the transceiver comes on, you may
release the buttons.
note:
The FT-991 cannot erase the memory channels “01”
(and “5-01” through “5-10”: U.S. version).
Menu reSetting
Use this procedure to restore the Menu settings to their
factory defaults, without affecting the programmed
memories.
1. Press the front panel ON/OFF switch to turn the
transceiver off.
2. While holding the MENU(SETUP) button in, press
and hold in the front panel ON/OFF switch to turn
the transceiver on. Once the transceiver comes on,
release the buttons.
Full reSet
Use this procedure to restore all Menu and Memory set-
tings to their original factory defaults. All Memories will
be cleared by this procedure.
1. Press the front panel ON/OFF switch to turn the
transceiver off.
2. While holding the FAST and LOCK buttons in,
press and hold in the front panel ON/OFF switch to
turn the transceiver on. Once the transceiver comes
on, release the buttons.
A

M buttonON/OFF Switch
MENU(SETUP) ButtonON/OFF Switch
FAST Button LOCK ButtonON/OFF Switch

Page 11
FT-991 OperaTing Manual
AntennA conSiderAtionS
The FT-991 is designed for use with any antenna system providing a 50 Ohm resistive impedance at the desired oper-
ating frequency. While minor excursions from the 50-Ohm specication are of no consequence, if the Standing Wave
Ratio (SWR) present at the Antenna jack is greater than 3:1, the transceiver’s Automatic Antenna Tuner may not be able
to reduce the impedance mismatch to an acceptable value.
Every effort should be made to ensure that the impedance of the antenna system be as close as possible to the specied
50-Ohm value. Note that the “G5RV” type antenna does not provide a 50-Ohm impedance on all HF Amateur bands. An
external wide-range antenna coupler must be used with this antenna type.
Any antenna to be used with the FT-991 must be fed from the transceiver with 50 Ohm coaxial cable. Therefore, when
using a “balanced” antenna such as a dipole, remember that a balun or other matching/balancing device must be used to
ensure proper antenna performance.
The same precautions apply to any additional (receive-only) antennas connected to the antenna jacks. If the receive only
antennas do not have impedance near 50 Ohms at the operating frequency, It may be necessary to install an external an-
tenna tuner to obtain optimum performance.
About coAxiAl cAble
Use high-quality 50-Ohm coaxial cable for the lead-in to your FT-991 transceiver. All efforts at providing an efcient
antenna system will be wasted if poor quality, lossy coaxial cable is used. This transceiver utilizes standard “M” (“PL-
259”) type connectors.
typicAl pl-259 inStAllAtion
before You beGin

Page 12 FT-991 OperaTing Manual
before You beGin
grounding
The FT-991 transceiver, like any other HF communications apparatus, requires an effective ground system for maxi-
mum electrical safety and best communications effectiveness. A good ground system can contribute to station efciency
in a number of ways:
 It can minimize the possibility of electrical shock to the operator.
 It can minimize RF currents owing on the shield of the coaxial cable and the chassis of the transceiver. Such cur-
rents may lead to radiation, which can cause interference to home entertainment devices or laboratory test equip-
ment.
 It can minimize the possibility of erratic transceiver/accessory operation caused by RF feedback and/or improper
current ow through logic devices.
An effective earth ground system may take several forms. For a more complete discussion, see an appropriate RF engi-
neering text. The information below is intended only as a guideline.
Typically, the ground connection consists of one or more copper-clad steel rods, driven into the ground. If multiple
ground rods are used, they should be positioned in a “V” conguration and bonded together at the base of the “V” which
is nearest the station location. Use a heavy, braided cable (such as the discarded shield from type RG-213 coaxial cable)
and strong cable clamps to secure the braided cable(s) to the ground rods. Be sure to weatherproof the connections
to ensure many years of reliable service. Use the same type of heavy, braided cable for the connections to the station
ground bus (described below).
Inside the station, a common ground bus consisting of a copper pipe of at least 25 mm diameter should be used. An al-
ternative station ground bus may consist of a wide copper plate (single-sided circuit board material is ideal) secured to
the bottom of the operating desk. Grounding connections from individual transceivers, power supplies, and data com-
munications devices (TNCs, etc.) should be made directly to the ground bus using a heavy, braided cable.
Do not “Daisy-Chain” ground connections from one electrical device to another and thence to the ground bus. This
method may nullify any attempt at effective radio frequency grounding. See the drawing below for examples of proper
grounding techniques.
Inspect the ground system - inside the station as well as outside - on a regular basis to ensure continued performance
and safety.
Besides following the above guidelines carefully, note that household or industrial gas lines must never be used in an
attempt to establish an electrical ground. Cold water pipes may, in some instances, help in the grounding effort, but gas
lines represent a signicant explosion hazard, and must never be used.
proper ground connection
GND
Linear
Amplifier
GND
TNC
GND
Transceiver
GND
Transceiver
GND
Linear
Amplifier
GND
TNC
"Daisy Chain"
GND
Linear
Amplifier
GND
TNC
GND
Transceiver
GND
Transceiver
GND
Linear
Amplifier
GND
TNC
"Daisy Chain"
iMproper ground connection

Page 13
FT-991 OperaTing Manual
before You beGin
connection oF AntennA And poWer cAbleS
Please follow the outline in the illustration regarding the proper connection of antenna coaxial cables, as well as the DC
power cable. The DC power connector for the
FT-991
must only be connected to a DC source providing 13.8 Volts DC (±15
%), and capable of at least 23 Amperes of current. Always observe proper polarity when making DC connection:
The RED DC power lead connects to the Positive (+) DC terminal.
The BLACK DC power lead connects to the Negative (–) DC terminal.
We recommend the use of the FP-1030A (USA market only) AC Power Supply. Other models of power supplies may
be used with the FT-991, but the 13.8 VDC input voltage, 23 Ampere current capability, and DC cable polarity guide-
lines described above must be strictly followed.
Note that other manufacturers may use the same type of DC power connections as the FT-991 transceiver; however, the
wiring conguration may be different from that specied for the FT-991 transceiver. Serious damage can be caused if
improper DC connections are made; consult with a qualied service technician when in doubt.
High RF voltage is present in the TX RF section of the transceiver while transmitting.
Absolutely! Do not touch the TX RF section while transmitting.
Permanent damage can result when improper supply voltage, or reverse-polarity voltage, is applied to the FT-
991. The Limited Warranty on this transceiver does not cover damage caused by application of AC voltage, re-
verse polarity DC, or DC voltage outside the specied range of 13.8 V ±15 %. When replacing fuses, be certain
to use a fuse of the proper rating. The FT-991 requires a 25 Amp blade fuse.
note:
Do not place the FT-991 in a location with direct exposure to sunshine.
Do not place the FT-991 in a location exposed to dust and/or high humidity.
Ensure adequate ventilation around the FT-991, to prevent heat build-up and possible reduction of performance due
to high heat.
Do not install the FT-991 on an unstable desk or table. Do not place it in a location where objects may fall onto it
from above.
To minimize the possibility of interference to home entertainment devices, take all precautionary steps including
separation of TV/FM antennas from Amateur transmitting antennas to the greatest extent possible, and keep trans-
mitting coaxial cables separated from cables connected to home entertainment devices.
Ensure that the DC power cord is not subject to undue stress or bending, which could damage the cable or cause it to
be accidentally unplugged from the rear panel DC IN jack.
Be certain to install your transmitting antenna(s) so they cannot possibly come in contact with TV/FM radio or other
antennas, or with power or telephone lines.
Check the DC volt-
age and current
rating (+13.8 V, 23 A) of the
power supply before con-
necting to the transceiver.
To prevent damage from
lightning, atmospheric elec-
tricity, electrical shock etc., please
provide a good earth ground.
Use a short,
thick, braided
cable to con-
nect your station
equipment to the
buried ground rod (or alternative earth
ground system).

Page 14 FT-991 OperaTing Manual
connection oF Microphone, heAdphone And reMote control keypAd
Lightweight Stereo
Headphone
YH-77STA
DOWN
UP
+5V
MIC GND
MIC
PTT
GND
FAST


note:
Make sure to turn off the power of the transceiver before connecting or disconnecting the microphone.
Remote Control Keypad
FH-2
installation anD interconnections
If the FH-2 plug is removed from the jack
while the FT-991 is in operation, the FT-991
may be switched to the transmit mode.
Turn off the power of the FT-991 before connecting or
disconnecting the FH-2.

Page 15
FT-991 OperaTing Manual
installation anD interconnections
key, keyer, And coMputer-driven keying interconnectionS
The FT-991 includes many features for the CW operator. These functions will be detailed in the “Operation” section
later. Besides the built-in Electronic Keyer, two key jacks are provided, one on the front and one on the rear panel, for
convenient connection to keying devices.
The Menu selections permit conguring the front panel KEY jack according to the device connected. For example, a
keyer paddle may be connected to the front panel KEY jack, and Menu item “012 KEYER TYPE” used to select paddle
input.
The KEY jack on the FT-991 utilize “Positive” keying voltage. Key-up voltage is approximately +3.3V DC, and key-
down current is approximately 4 mA. When connecting a key or other device to the KEY jack, use only a 3-contact
(“stereo”) 1/4” phone plug; a 2-contact plug will place a short between the ring and shaft (ground) of the plug, resulting
in a constant “key-down” condition in some circumstances.
Single key/Double-speed key Manipulator
DOT DASH COMMON
DOT DASH COMMON
KEY
KEY
NC GND
GND
If the Keyer plug is removed from the jack while the FT-991 is in operation,
the FT-991 may be switched to the transmit mode.
Turn off the power of the FT-991 before connecting or disconnecting the Keyer.

Page 16 FT-991 OperaTing Manual
vl-1000 lineAr AMpliFier interconnectionS
Be sure that both the FT-991 and VL-1000 are turned off, and then follow the installation recommendations contained
in the illustration.
note:
Refer to the VL-1000 Operating Manual for details regarding amplier operation.
Do not attempt to connect or disconnect coaxial cables when your hands are wet.
Set the Menu item “143 TUNER SELECT” to “LAMP”.
Since the ALC cable is connected to the REM/ALC jack, the optional FH-2 cannot be connected.
DC 13.8 V
CT-58 ALC Cable (Option)
CT-58 Band Data Cable (Option)
144/430MHz Antenna HF/50MHz Antenna
Coaxial Cable (50Ω)
Connect to “INPUT 1” of the VL-1000
INPUT
BAND-DATA 1
ALC 1
TUN/LIN
REM/ALC
GND
GND
VP-1000 VP-1000 CONTROL
DC 48V IN
ANT 1 ANT 2 ANT 3 INPUT 1
ANT 144/430MHz ANT HF/50MHz
To link the FT-991 and VL-
1000 Power switches, set the
VL-1000 REMOTE switch to
the “ON” position.
Set the front panel’s
INPUT switch to the
“INPUT1”.
installation anD interconnections

Page 17
FT-991 OperaTing Manual
InstallatIon and InterconnectIons
Plug/ConneCtor Pinout Diagrams
MIC GPS/CAT
DOWN
UP
+5V
MIC GND
MIC
PTT
GND
FAST


① DCD
② SERIAL OUT/RXD
（GPS DATA IN）
③ SERIAL IN
④ DTR
⑤ GND
⑥ DSR
⑦ RTS
⑧ CTS
⑨ RI
①②③④⑤
⑧⑨ ⑦ ⑥
(as viewed from front panel) (as viewed from rear panel)
RTTY/DATA TUN/LIN
DATA IN
GND
DAKY
SHIFT
RTYO
BUSY
 
 

+13V OUT
TX GND
GND
TX D (BAND A)
RX D (BAND B)
BAND C

RESET (BAND D)
TX INH







(as viewed from rear panel) (as viewed from rear panel)
DC IN KEY
Manipulator Single key/Double-speed key
DOT KEY GNDDASH COMMON
(as viewed from rear panel)
Do not use
2-conductor type plug
EXT SPKR, REM/ALC PHONE
SIGNAL GND
SIGNAL (LEFT)
SIGNAL (RIGHT)
GND

Page 18 FT-991 OperaTing Manual
ON/OFF Switch
Press and hold in this switch for one second to turn
the transceiver on. Similarly, press and hold in this
switch for one second to turn the transceiver off.
mConnect the FT-991 transceiver to a commercial-
ly available DC power supply. Turn the DC sup-
ply on to place the transceiver in standby mode.
The transceiver must be in standby mode to turn
it on using the ON/OFF switch. For details on
how to connect a commercially available DC
power supply, see page 13.
mPress the ON/OFF switch briey while the pow-
er is on, the receiver audio from the speaker will
be muted for about 3 seconds (Mute function).
KEY Jack
Connect a telegraph key or electronic keyer paddle
to use for CW mode operation.
KEY
KEY
NC GND
GND
When connecting a single straight key
DOT DASH COMMON
DOT DASH COMMON
When connecting an electronic keyer paddle
mWhen connecting a key or other device to the
KEY jack, use only a 3-contact (“stereo”) 1/4”
phone plug; a 2-contact plug will place a short
between the ring and the (grounded) shaft of the
plug, resulting in a constant “key-down” condi-
tion.
mKey-up voltage is +3.3 V, and key-down current
is about 4 mA.
note:
A 2-contact plug cannot be used in this jack.
PHONES Jack
Connect headphones to this ϕ3.5 standard stereo
jack.
mInserting a headphone plug into this jack will de-
activate the internal and external speakers.
note:
When wearing headphones, we recommend that you
turn the AF Gain levels down to their lowest settings
before turning power on, to minimize the impact on
your hearing caused by audio “pops” during switch-on .
MIC Jack
This 8-pin jack accepts input from a microphone uti-
lizing a traditional YAESU HF transceiver pinout.
DOWN
UP
+5V
MIC GND
MIC
PTT
GND
FAST


front panel controls & switches
4
3
2
1
5
789
6