Yaesu FT-891 Manual

Specications
Exploded View
Block Diagram
Connection Diagram
Alignment
Board Unit (Schematics, Layouts & Parts)
MAIN Unit
LOCAL Unit
PA Unit
DSP Unit
PANEL Unit
SW-A Unit
SW-B Unit
VR Unit
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-
qualied 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 specication.
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 specication, 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.

FT-891 Technical Supplement
Specications
SPECIFICATIONS-1
General
Frequency Range: Tx: 1.8 MHz - 54 MHz (Amateur bands only)
Rx: 30 kHz - 56 MHz
1.8 MHz - 54 MHz
(Specified performance, Amateur bands only)
Channel Step: 2/5/10 Hz (SSB, CW)
10/100 Hz (AM, FM)
Frequency Stability: SSB/CW/AM: ±0.5 ppm [14 °F to +122 °F (-10 °C to +50 °C)]
FM: ±1 kHz [14 °F to +122 °F (-10 °C to +50 °C)]
Modes of Emission: A1A (CW), A3E (AM), J3E (LSB, USB), F3E (FM)
Antenna Impedance: 50 Ohms, unbalanced
Supply voltage: 13.8 V DC ±15%, negative ground
Current Consumption (typical): Rx: 2.0 A (signal present)
Tx: 23 A
Operating Temperature Range: 14 °F to +122 °F (-10 °C to +50 °C)
Case Size (W x H x D): 6.1” x 2.0” x 8.6” (155 x 52 x 218 mm) (w/o knobs)
Weight (Approx.): 4.18 lb (1.9 kg)
Transmitter
Power Output: 100 W (40 W AM carrier)
Modulation Type: J3E (SSB): Balanced,
A3E (AM): Low-Level,
F3E (FM): Variable Reactance
Maximum Deviation: ±5.0 kHz (Wide)
±2.5 kHz (Narrow)
Spurious Radiation: Better than -50 dB (
1.8 MHz - 30 MHz Amateur bands )
Better than -63 dB (50 MHz Amateur bands)
Microphone Impedance: 600 Ohms (200 Ohms to 10 k Ohms)

FT-891 Technical Supplement
Specications
SPECIFICATIONS-2
Receiver
Circuit Type: SSB/CW/AM: Triple-conversion Superheterodyne
FM: Double Conversion Superheterodyne
Intermediate Frequencies: SSB/CW/AM: 1st: 69.450 MHz
2nd: 450 kHz
3rd: 24 kHz
FM: 1st: 69.450 MHz
2nd: 450 kHz
Sensitivity: SSB/CW (S/N 10 dB)
0.16 μV (1.8 MHz - 30 MHz)
0.16 μV (50 MHz - 54 MHz)
AM (S/N 10 dB)
5 μV (0.5 MHz - 1.8 MHz)
1.6 μV (1.8 MHz - 30 MHz)
1.6 μV (50 MHz - 54 MHz)
FM (12 dB SINAD)
0.35 μV (29 MHz, 50 MHz - 54 MHz)
Selectivity: Mode -6 dB -60 dB
SSB/CW 2.4 kHz or better 3.6 kHz or less
CW-N 500 Hz or better 750 Hz or less
AM 6 kHz or better 15 kHz or less
FM 12 kHz or better 30 kHz or less (-50dB)
FM-N 9 kHz or better 25 kHz or less (-50dB)
Maximum AF Output: 2.5 W into 4 ohms with 10% THD
Audio Output Impedance: 4 Ohms to 16 Ohms (8 Ohms: nominal)
Conducted Radiation: Less than 4 nW
Specifications are subject to change, in the interest of technical improvement, without notice or obligation,
and are guaranteed only within the amateur bands.

EXPLODED VIEW-1 FT-891 Technical Supplement
Exploded View
REF. YAESU P/N Description Qty.
①U03106001 SEMS SCREW ASM2X6 4
②U24206001 BIND HEAD TAPTITE-B M2.6X6 11
③U24208007 BIND HEAD TAPTITE-B M2.6X8B 5
④U04410002 SEMS SCREW HSM4X10NI 1
⑤U24306001 BIND HEAD TAPTITE-B M3X6 2
⑥U31206007 OVAL HEAD SCREW M2.6X6B 4
Non-designated parts are available only as psrt of a designated assembly.
③
④
RA6112100 (Lot. 1-6)
PORON SHEET(FAN)
RA6112100 (Lot. 7-)
PORON RUBBER(FAN)
②
①
M2090062
FAN
⑤
RA6075300
CHASSIS
DSP Unit
RA6078700
SHIELD CASE COVER
⑤
①①
①
MAIN Unit
RA6121200
ThermalConductivePad
②
②
②
②
②
②
②
②
②
②
T9207337
WIRE ASSY 70MM30P
T9207694
WIRE ASSY 190MM2P
T9207692
WIRE ASSY 150MM2P
T9207690
WIRE ASSY 80MM2P
M4090264
SPEAKER
T9207700
WIRE ASSY 110MM2P
P1091158B
CONNECTOR
RA6115100
PORON SHEET
RA6033500
GASKET (10x20)
RA6094600
TOP CASE ASSY
RA6090100
GASKET(10X70)
RA123330A
SHEET
RA6082300
BLIND SHEET(SP)
RA045320A
GASKET (SHIELD)
③
③
③
③
RA6075400
RUBBER PACKING (SP)
⑥
⑥
⑥
⑥
RA607510A
SUB PANEL ASSY
CS2461702 (USA)
CS2461703 (EU)
MAIN-1 ASSY
CS2462501
DSP ASSY
RA6079100
SHIELD CASE PLL
RA6079200
SHIELD CASE COVER
RA6079500
SHIELD CASE
RA1152400
SHIELD CASE COVER
RA6079400
SHIELD CASE COVER
RA6079100
SHIELD CASE
RA6091600
SHIELD PLATE
RA6115700 (2 pcs)
BUSTERAID(12.5X10)
T9101530A
CT CABLE

EXPLODED VIEW-2 FT-891 Technical Supplement
Exploded View
REF. YAESU P/N Description Qty.
①U24206001 BIND HEAD TAPTITE-B M2.6X6 14
②U03310002 SEMS SCREW ASM3X10NI 4
③U24208007 BIND HEAD TAPTITE-B M2.6X8B 3
④U03305002 SEMS SCREW ASM3X5NI 2
⑤U31206007 OVAL HEAD SCREW M2.6X6B 8
⑥U20305007 BINDING HEAD SCREW M3X5B 2
⑦U9900144 BINDING HEAD SCREW M3X7B 2
Non-designated parts are available only as psrt of a designated assembly.
T9207686
CHASSISWIRE ASSY 74MM4P
RA6076300
GROUND PLATE (FET-S)
①
②
②②
②
③
③
③
①
①
①
①
①①
①
①
①
①①
①
①
RA0129800
LEAF SPRING
S5000260
LEAD CLAMP
④④
RA0484100
SPONGE RUBBER(REG)
RA6075600
BOTTOM CASE
RA6121300
ThermalConductivePad
RA0469800
LEG (A)
RA6075700
STAND
⑥
⑥
⑦
⑦
S4000060
CASE LEG
RA0471500
ELEC. COND TAPE(C)
⑤
⑤
⑤
⑤
⑤
⑤
⑤
⑤
RA6112000
PORON SHEET (5106)
RA6068800
SHIELD CASE(19x25)
R8139500A
LABEL 030X006R
R8139500A
LABEL 030X006R
RA6075800
DISPLAY PANEL (FCC)
CS2460401
PA ASSY
PA Unit

EXPLODED VIEW-3 FT-891 Technical Supplement
Exploded View
REF. YAESU P/N Description Qty.
①U43110007 PAN HEAD TAPTITE-P M2X10B 4
②U24108001 BIND HEAD TAPTITE-B M2X8(3) 2
③U24105001 BIND HEAD TAPTITE-B M2X5(3) 2
④U24206001 BIND HEAD TAPTITE-B M2.6X6 2
Non-designated parts are available only as psrt of a designated assembly.
RA6074100
SPONGE RUBBER(LCD)
RA1107900
PORON SHEET5X15X1
Q7000692
LCD MODULE
SW-A Unit
SW-B Unit
RA6088900
DIFFUSER SHEET
RA6081700
REFLECTOR
RA6073800
LIGHT GUIDE
RA607360A
FRONT PANEL(PRT)
PANEL Unit
②
②
①
①
①
①
RA607400A
RUBBER KNOB(TOP)
VR Unit
R6054387B
SPECIAL NUT
RA6073900
RUBBER KNOB(FRONT)
③
③
U70015001
PLAIN WASHER FW9X14X0.5
U62009001
VOLUME NUT 9X12X2
Q9001000
ROTARY ENCODER
R8151700
LABEL"CAUTION"
RA6074700
RUBBER RING(MAIN)
RA6075000
REAR PANEL
RA6074400 (Lot. 1-7)
RA607440A (Lot. 8-)
KNOB MAIN ASSY
RA152820A
WASHER(FELT)
RA1528400
WASHER(PE)
RA604250B
VOLUME KNOB(OUT)
RA604240A
VOLUME KNOB(IN)
RA6074300
ENCODER KNOB
RA6074900
LEVER
U9900211
WAVE WASHER
RA6074800
HOLDER(SPRING)
④
④
RA6074200
LCD SPACER
CQ0675001
PANEL ASSY

BLOCK DIAGRAM-1 FT-891 Technical Supplement
Block Diagram

CONNECTION DIAGRAM-1 FT-891 Technical Supplement
Connection Diagram

FT-891 Technical Supplement
Alignment
ALIGNMENT-1
Introduction and Precautions
The following procedures cover adjustments that
are not normally required once the transceiver
has left the factory. However, if a problem occurs
during normal operation due to component failure;
realignment may be required after the faulty com-
ponents have been replaced.
We recommend that authorized Yaesu Techni-
cians, who are experienced with the circuitry and
fully equipped to repair and align our products,
perform repairs. If a fault is suspected, contact the
selling dealer for instructions regarding repair.
Authorized Yaesu Technicians have the latest infor-
mation to align all circuits and make complete per-
formance checks to ensure compliance with factory
specications after repairs.
Those who do undertake any of the following
alignments are cautioned to proceed at their own
risk. Problems caused by unauthorized aempts at
realignment are not covered by the warranty poli-
cy.
Yaesu must reserve the right to change circuits and
alignment procedures in the interest of improved
performance, without notifying owners.
Under no circumstances should any alignment be
aempted unless the normal functions and opera-
tion of the transceiver are clearly understood, the
cause of the malfunction has been clearly identied
and all faulty components replaced. The need for
realignment should be determined to be absolutely
necessary.
The following test equipment (and a thorough fa-
miliarity with its correct use) is necessary for cor-
rect realignment. Most steps do not require all of
the equipment listed. The interactions of some ad-
justments may require that more complex adjust-
ments be performed in a sequence. Do not aempt
to perform only a single step unless it is clearly iso-
lated electrically from all other steps. Have all test
equipment ready before beginning, and follow all
of the steps in a section in the order they are pre-
sented.
Required Test Equipment
RF Signal Generator
AF Signal Generator
Spectrum Analyzer good to at least 1 GHz.
Frequency Counter
SINAD Meter
RF Millivoltmeter
Electronic Load
Digital DC Voltmeter (high-Z, 1 M-Ohm/V)
DC Voltmeter
DC Ammeter (23 A)
Ohmmeter
 16-Ohm Dummy Load (100/200 was)
 50-Ohm Dummy Load (100/200 was)
 150-Ohm Dummy Load (100/200 was)
 In-Line Wameter (150/300 was, 50-Ohm)
Linear Detector
RF Coupler
 4-Ohm AF Dummy Load (3 was)
3.5 mm 3-contact Plug
Alignment Preparation & Precautions
A 50-ohm RF Dummy load and in-line wameter
must be connected to the ANT jack in all proce-
dures that call for transmission, except where spec-
ified otherwise. Correct alignment is not possible
with an antenna.
After completing one step, read the following step
to determine whether the same test equipment
will be required. If not, remove the unneeded test
equipment before proceeding. (except the dummy
load and wameter).
Correct alignment requires that the ambient tem-
perature be maintained constant between 68 °F ~ 86
°F (20 °C ~ 30 °C). When the transceiver is brought
into the shop from a hot or cold environment, it
should be allowed time to come to room tempera-
ture before alignment. Also, the test equipment
must be thoroughly warmed up before beginning.
Whenever possible, alignments should be made
with oscillator shields and circuit boards rmly af-
xed in place.
Note: Signal levels in dB referred to in this proce-
dure are based on 0 dBμ = 0.5 μV (closed cir-
cuit).
Important Notice
Do not adjust the alignment menus that are
not mentioned in this manual.

FT-891 Technical Supplement
Alignment
ALIGNMENT-2
VDD Meter Adjustment
Connect the DC voltmeter to J5017 on the PA-
Unit.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “01-01 VDD MTR”.
Press the [CLAR]key, then rotate the [RF/SQL]
knob so the parameter reading is the same as
the reding on the DC voltmeter (13.8 V).
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
J5017

FT-891 Technical Supplement
Alignment
ALIGNMENT-3
VCO Adjustment
Connect the Digital DC voltmeter (high-Z) to
TP1009 on the MAIN Unit.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Referring to the table below, select the
appropriate “Alignment menu item” using the
[MULTI]function knob per the chart right, and
adjust the listed components on the LOCAL
Unit for the required voltage, or confirm that
the correct voltage is present on each alignment
menu item.
Alignment Menu Item Adjust / Conrm DC voltmeter
01-04 VCO1-HIGH (TXI) Adjust L4002 4.2 V ±0.1 V
01-05 VCO1-LOW Conrm At least 0.45 V
01-06 VCO2-HIGH Adjust L4004 4.2 V ±0.1 V
01-07 VCO2-LOW Conrm At least 0.6 V
01-08 VCO3-HIGH Adjust L4006 4.2 V ±0.1 V
01-09 VCO3-LOW Conrm At least 0.25 V
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
TP1009 L4002 L4004 L4006

FT-891 Technical Supplement
Alignment
ALIGNMENT-4
2nd/3rd Local Oscillator Adjustment
Set the VFO-A frequency to 14.200 MHz in the
CW-USB mode.
Set the following controls as indicated:
[IPO]: ON
[ATT]: OFF
[NB]: OFF
[AGC]: AUTO
[RF GAIN]: Fully clockwise
3rd Local Level Adjustment
Connect the RF millivoltmeter to TP1041 on the
MAIN Unit.
Adjust T1023 on the MAIN Unit for maximum
deflection on the RF millivoltmeter.
2nd Local Level Adjustment
Connect the RF millivoltmeter to TP1022 on the
MAIN Unit.
Adjust T1013, T1014 and T1016 on the MAIN
Unit for maximum deflection on the RF
millivoltmeter.
REF OSC Adjustment
Connect the frequency counter to TP1022.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “01-02 REF FREQ”.
Rotate the [RF/SQL]knob so that the frequency
counter reading is “69.000000 ±5 Hz”.
Disconnect the frequency counter from TP1022.
Connect the frequency counter to J1002.
Press and hold the PTT switch, then rotate the
[RF/SQL]knob so that the frequency counter
reading is “50.000000 ±150 Hz”.
Release the PTT switch.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
TP1041
TP1022
T1016
T1014
T1013
T1023
J1002

FT-891 Technical Supplement
Alignment
ALIGNMENT-5
1st Local Oscillator Adjustment
Connect the 3.5 mm Plug to KEY jack on the
transceiver.
Connect the RF millivoltmeter to TP1005 on the
MAIN Unit.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “02-01 Local 1.8”.
Press and hold the PTT switch, then rotate the
[RF/SQL]knob so that the RF millivoltmeter
reading is “+11.0 dBm ±0.5 dBm” (Lot. 1-10) or
“+7.0 dBm ±0.5 dBm” (Lot. 11-).
Release the PTT switch.
Rotate the [MULTI]function knob to select the
alignment menu item “02-02 Local HFL”.
Press and hold the PTT switch, then rotate the
[RF/SQL]knob so that the RF millivoltmeter
reading is “+10.0 dBm ±0.5 dBm” (Lot. 1-10) or
“+8.0 dBm ±0.5 dBm” (Lot. 11-).
Release the PTT switch.
Rotate the [MULTI]function knob to select the
alignment menu item “02-03 Local HFM”.
Press and hold the PTT switch, then rotate the
[RF/SQL]knob so that the RF millivoltmeter
reading is “+10.0 dBm ±0.5 dBm” (Lot. 1-10) or
“+9.0 dBm ±0.5 dBm” (Lot. 11-).
Release the PTT switch.
Rotate the [MULTI]function knob to select the
alignment menu item “02-04 Local HFH”.
Press and hold the PTT switch, then rotate the
[RF/SQL]knob so that the RF millivoltmeter
reading is “+10.0 dBm ±0.5 dBm” (Lot. 1-10) or
“+8.0 dBm ±0.5 dBm” (Lot. 11-).
Release the PTT switch.
Rotate the [MULTI]function knob to select the
alignment menu item “02-05 Local 50”.
Press and hold the PTT switch, then rotate the
[RF/SQL]knob so that the RF millivoltmeter
reading is “+7.5 dBm - +8.0 dBm” (Lot. 1-10) or
“+7.0 dBm ±0.5 dBm” (Lot. 11-).
Release the PTT switch.
Alignment Menu Item RF millivoltmeter
Lot. 1 - 10 Lot. 11 -
02-01 Local 1.8 +11.0 dBm ±0.5 dBm +7.0 dBm ±0.5 dBm
02-02 Local HFL +10.0 dBm ±0.5 dBm +8.0 dBm ±0.5 dBm
02-03 Local HFM +10.0 dBm ±0.5 dBm +9.0 dBm ±0.5 dBm
02-04 Local HFH +10.0 dBm ±0.5 dBm +8.0 dBm ±0.5 dBm
02-05 Local 50 +7.5 dBm - +8.0 dBm +7.0 dBm ±0.5 dBm
Disconnect the 3.5 mm Plug from KEY jack on
the transceiver.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
TP1005

FT-891 Technical Supplement
Alignment
ALIGNMENT-6
MCF Adjustment
Set the VFO-A frequency to 14.200 MHz in the
CW-USB mode.
Set the following controls as indicated:
[IPO]: ON
[ATT]: OFF
[AGC]: AUTO
[RF GAIN]: Fully clockwise
Connect the AF millivoltmeter and 4 Ohm
dummy load to the EXT SP jack.
Connect the RF Signal Generator to the ANT
jack, then set the output level to +10 dBμ at the
14.200 MHz.
Adjust T1011 and T1012 on the MAIN Unit
in succession several times for maximum
deflection on the AF millivoltmeter.
Note: If the S-meter deflects while adjusting,
reduce the RF Signal Generator output so
that the S-meter does not deflect.
IF Trap Adjustment
Set the VFO-A frequency to 51.900 MHz in the
CW-USB mode.
Set the following controls as indicated:
[IPO]: ON
[ATT]: OFF
[AGC]: AUTO
[RF GAIN]: Fully clockwise
Connect the AF millivoltmeter and 4 Ohm
dummy load to the EXT SP jack.
Connect the RF Signal Generator to the ANT
jack, then set the output level to +40 ~ +80 dBμ
at the 69.450 MHz.
Adjust T1005 on the MAIN Unit for minimum
deflection on the AF millivoltmeter.
Note: If the S-meter deflects while adjusting,
reduce the RF Signal Generator output so
that the S-meter does not deflect.
T1011 T1012 T1005

FT-891 Technical Supplement
Alignment
ALIGNMENT-7
RF AGC Adjustment
Set the VFO-A frequency to 14.200 MHz in the
CW-USB mode.
Set the following controls as indicated:
[IPO]: ON
[ATT]: OFF
[AGC]: AUTO
[RF GAIN]: Fully clockwise
Connect the RF Signal Generator to the ANT
jack, then set the output level to +76 dBμ at the
14.200 MHz.
Connect the Digital DC voltmeter (high-Z) to
TP1016 on the MAIN Unit.
Adjust VR1001 on the MAIN Unit so that the
Digital DC voltmeter reading is “1.2 V ±0.2 V”.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
VR1001TP1016

FT-891 Technical Supplement
Alignment
ALIGNMENT-8
IF Gain Adjustment
Set the following controls as indicated:
[IPO]: ON
[ATT]: OFF
[AGC]: AUTO
[RF GAIN]: Fully clockwise
Connect the AF millivoltmeter and 4 Ohm
dummy load to the EXT SP jack.
Connect the RF Signal Generator to the ANT
jack, then set the output level to +36 dBμ at 1.900
MHz.
Set the VFO-A frequency to 1.900 MHz in the
CW-USB mode.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Adjust the [AF]knob so that the AF
millivoltmeter reading is “0 dB”.
Set the RF Signal Generator output level to +10
dBμ.
Adjust the [RF/SQL]knob so that the AF
millivoltmeter reading is “-1.5 ± 0.5 dB”.
Select the appropriate “Alignment menu item”
using the [MULTI]function knob per the
chart below, then set the RF Signal Generator
output to each frequency & level, and adjust
the [RF/SQL]knob for the corresponding AF
millivoltmeter reading at each frequency.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
Alignment
menu item
VFO-A
Frequency
RF Signal
Generator Adjust AF milli-
voltmeter
04-01 IGC 1.8 1.900 MHz
1.900 MHz
+36 dBµ [AF]knob 0 dB
1.900 MHz
+10 dBµ
[RF/SQL]
knob
-1.5 dB
(±0.5 dB)
04-02 IGC HFL 7.100 MHz
7.100 MHz
+36 dBµ [AF]knob 0 dB
7.100 MHz
+10 dBµ
[RF/SQL]
knob
-1.5 dB
(±0.5 dB)
04-03 IGC HFM 14.200 MHz
14.200 MHz
+36 dBµ [AF]knob 0 dB
14.200 MHz
+10 dBµ
[RF/SQL]
knob
-1.5 dB
(±0.5 dB)
04-04 IGC HFH 21.200 MHz
21.200 MHz
+36 dBµ [AF]knob 0 dB
21.200 MHz
+10 dBµ
[RF/SQL]
knob
-1.5 dB
(±0.5 dB)
04-05 IGC 50 51.900 MHz
51.900 MHz
+36 dBµ [AF]knob 0 dB
51.900 MHz
+7 dBµ
[RF/SQL]
knob
-1.5 dB
(±0.5 dB)
S-meter Adjustment
Set the VFO-A frequency to 14.200 MHz in the
CW-USB mode.
Set the following controls as indicated:
[IPO]: ON
[ATT]: OFF
[AGC]: AUTO
[RF GAIN]: Fully clockwise
Connect the RF Signal Generator to the ANT
jack, then set the frequency to 14.200 MHz.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Refer to the chart below and select the
appropriate “Alignment menu item” using
the [MULTI]function knob. Set the RF Signal
Generator output to each level, and adjust the
[RF/SQL]knob for the corresponding S-meter
reading. Press the [CLAR]key to save the new
setting at each level.
Alignment menu item RF Signal
Generator S-meter
05-01 S-MTR 0 OFF S-0
05-02 S-MTR 1 +14 dBµ S-1
05-03 S-MTR 5 +24 dBµ S-5
05-04 S-MTR 7 +30 dBµ S-7
05-05 S-MTR 9 +36 dBµ S-9
05-06 S-MTR +10 +46 dBµ S-9+10dB
05-07 S-MTR +20 +56 dBµ S-9+20dB
05-08 S-MTR +30 +66 dBµ S-9+30dB
05-09 S-MTR +40 +76 dBµ S-9+40dB
05-10 S-MTR +50 +86 dBµ S-9+50dB
05-11 S-MTR +60 +96 dBµ S-9+60dB
Press and hold in the [F]key to save the new
setting and exit the alignment mode.

FT-891 Technical Supplement
Alignment
ALIGNMENT-9
FIL Gain Adjustment
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “06-01 R. FIL 3k”.
Rotate the [RF/SQL]knob to set the parameter
is “180”.
Rotate the [MULTI]function knob to select the
alignment menu item “06-02 R. FIL 15k”.
Rotate the [RF/SQL]knob to set the parameter
is “180”.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
S-meter Adjustment (FM)
Set the VFO-A frequency to 51.500 MHz in the
FM mode.
Connect the RF Signal Generator to the ANT
jack, then set the output level to 0 dBμ at
the 51.500 MHz with ±3.5 kHz deviation FM
modulation of a 1 kHz audio signal.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “07-01 FM S1”.
Rotate the [RF/SQL]knob so that the S-meter
reading is “S-1”.
Press the [CLAR]button to save the new
setting.
Set the RF Signal Generator to +20 dBμ.
Rotate the [MULTI]function knob to select the
alignment menu item “07-02 FM S9”.
Rotate the [RF/SQL]knob so that the S-meter
reading is “S-9”.
Press the [CLAR]button to save the new
setting.
Set the RF Signal Generator to +40 dBμ.
Rotate the [MULTI]function knob to select the
alignment menu item “07-03 FM S60”.
Rotate the [RF/SQL]knob so that the S-meter
reading is “S-9+60”.
Press the [CLAR]button to save the new
setting.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
FM Squelch Adjustment
Set the VFO-A frequency to 51.500 MHz in the
FM-WIDE mode.
Connect the RF Signal Generator to the ANT
jack, then set the output level to -8 dBμ at
the 51.500 MHz with ±3.5 kHz deviation FM
modulation of a 1 kHz audio signal.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “08-01 FM SQL TH”.
Press the [CLAR]button to save the new
setting.
Set the RF Signal Generator to +3 dBμ.
Rotate the [MULTI]function knob to select the
alignment menu item “08-02 FM SQL TI”.
Press the [CLAR]button to save the new
setting.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.
FM Center Stop Adjustment
Set the VFO-A frequency to 51.500 MHz in the
FM-WIDE mode.
Connect the RF Signal Generator to the ANT
jack, then set the output level to +3 dBμ at the
51.497 MHz.
Press and hold in the [A], [B]and [C]keys,
while turning the radio on, to enter the
alignment mode.
Rotate the [MULTI]function knob to select the
alignment menu item “09-01 FM CTR-Lo”.
Press the [CLAR]button to save the new
setting.
Set the RF Signal Generator to 51.503 MHz.
Rotate the [MULTI]function knob to select the
alignment menu item “09-02 FM CTR-Hi”.
Press the [CLAR]button to save the new
setting.
Press and hold in the [F]key to save the new
setting and exit the alignment mode.

FT-891 Technical Supplement
Alignment
ALIGNMENT-10
TX IFT Adjustment
Disconnect the coaxial cable from J1002 on
the MAIN Unit, then connect the Spectrum
Analyzer to J1002.
Set the VFO-A frequency to 51.500 MHz in the
CW-USB mode.
Set the TX Power to 100 W.
Press the PTT switch, adjust T1025 on the
spurious (69.450 MHz) for minimum deflection
on the Spectrum Analyzer.
Release the PTT switch.
Disconnect the Spectrum Analyzer from J1002,
then re-connect the coaxial cable to J1002.
T1025J1002

FT-891 Technical Supplement
Alignment
ALIGNMENT-11
PA Unit Adjustment
Preparation
Connect the Microphone to the Microphone
jack.
Connect the 50-Ohm Dummy Load and
Wattmeter to the ANT jack.
Disconnect the cable from J5001 on the PA Unit,
then terminate J5001 with a 50-Ohm resistor.
Disconnect the jumper plug from J5003.
Connect the DC ammeter to J5003.
Press and hold the PTT switch, while adjust
VR5001 so the DC ammeter reading is “55 mA
(±5 mA)”.
Release the PTT switch.
Disconnect the DC ammeter from J5003.
Disconnect the jumper plugs from J5005.
Connect the DC ammeter to J5005.
Press and hold the PTT switch, while adjust
VR5002 so the DC ammeter reading is “1.0 A
(±0.1 A)”.
Release the PTT switch.
Disconnect the DC ammeter from J5005.
Connect the DC ammeter to the Power Supply.
Turn both VR5003 and VR5004 fully counter-
clockwise.
Press and hold the PTT switch, while adjust
VR5003 so that the DC ammeter “1.0 A (±0.1 A)”
increase.
Adjust VR5004 so that the DC ammeter “1.0 A
(±0.1 A)” increase.
Release the PTT switch.
Re-connect the jumper plugs to J5003 and J5005.
Disconnect the DC ammeter from the Power
Supply.
Disconnect the 50-Ohm resistors from J5001,
then connect the cable to J5001.
J5001
J5003
VR5002
J5005
VR5001
VR5004
VR5003

FT-891 Technical Supplement
Alignment
ALIGNMENT-12
CM Coupler Balance Adjustment
Connect the 50-Ohm Dummy Load and
Wattmeter to the ANT jack.
Connect the Digital DC voltmeter (high-Z) to
TP5003 on the PA Unit.
Connect the Audio Generator to pin 8 of the
Microphone jack (pin 7: GND), then set the
output level to 0.5 mV @1 kHz.
Set the VFO-A frequency to 50.150 MHz in the
USB mode.
Press the PTT switch, then adjust the MIC
gain to set the RF Power output to 50 W on the
Wattmeter.
Press the PTT switch, adjust TC5001 for
minimum deflection on the DC voltmeter (less
than 0.3 V).
Release the PTT switch.
TP5003
TC5001