Yaesu FT-901DM User manual

INSTRUCTION
MANUAL
FT-901DM
YAESU MUSEN CO., LTD.

TABLE CONTENTS
GENERAL
SPECIFICATIONS
CONTROLS AND SWITCHES
REAR APRON CONNECTIONS. .
INSTALLATION
OPERATION
BLOCK DIAGRAM. es
CIRCUIT DESCRIPTION
MAINTENANCE AND ALIGNMENT.

ALL
MODE
HF
TRANSCEIVER
FT-901DM
GENERAL DESCRIPTION
The FT-901DM is a precision engineered, high-
performance HF transceiver of advanced design,
providing all band coverage (160 - 10 meters) on
all modes of operation: LSB, USB, CW, FSK, AM,
and FM. This transceiver operates at an input
power of 180 watts SSB/CW and 80 watts on AM,
FM, and FSK.
Advanced features include PLL (Phase Locked
Loop) frequency derivation, digital plus analog
frequency readout with large display LED digits,
a built-in Curtis 8043 IC electronic keyer, and
memory frequency control circuitry. State-of-the-
art receiver performance features include rejection
tuning,
dual-filter
variable
IF
bandwidth
tuning.
and,
for
CW.
an
audio
peak
filter
(APF)
for
un-
surpassed
rejection
of
unwanted
signals.
Other
built-in
features
include
VOX,
semi-break-in
CW
with
sidetone,
25
kHz
calibrator,
advanced
noise
blanker,
RF
speech
processor.
and
a
20
dB
RF
attenuator
for
protection
against
receiver
overload.
All
circuits,
except
the
transmitter
driver
and
final
amplifier
stages,
are
solid
state,
utilizing
modern
plug-in
printed
circuit
boards,
thus
per-
mitting
easy
maintenance.
The
FT-901DM
transceiver
is
entirely
self-con-
tained,
requiring
only an antenna
and power
source
for operation.
For base station
operation,
AC
power
voltages
of
100/110/117/200/220/234
VAC
may be chosen,
though
the unit normally
is sup-
plied with 117 volt capability.
A DC-DC
converter
unit provides
for mobile
or portable
operation.
Selection
of AC or DC power
source
is automati-
cally made when the proper
line cord is inserted.
For mobile operation a separate switch is provided
on
the
front
panel
to
turn
off
the
tube
heaters
while in the receive mode. With the heaters off,
current consumption is only 1.1 amp.
Among
the
available
options
on
economy
models
FT901D/SD/DE
are
the
memory
unit,
the
keyer
unit,
the
DC-DC
converter,
the
FM
unit,
and
the
cooling
fan.
Optional
equipment
on
all
models
are
the 600 Hz CW filter and the 6 kHz AM filter.
The entire FT-901DM transceiver weighs approxi-
mately
18
kg.,
and
is
342
mm
wide,
154
mm
high,
and
324
mm
deep.
A
diecast
front
panel
and
heavy-duty
case
provide
maximum
protection
against
damage
from
shock
and
vibration
during
travel use.

SPECIFICATIONS
GENERAL
Frequency
coverage:
160m 18-20 Mile
80m 35-40. MHz
410 70-75 MHz
20m 14.0-18,5 MHz
15m 21,0-21.5 Mz
Toma 28,0- 28.5 MHz
10m 28:5-29.0MHz
Vom 29,0- 29.5 MHz
1mb 29.5. 29.9 Mile
WWV/LIY 15.0-15.5 Milz, RX only
Power requirements:
‘AC 100/{10/117/200/220/234 W, $0}60 Ile
DC. 13.5 V, negative ground
(DC option FT-901D/SDIDF)
Power consumption:
(FT-901DM/D/DE
ACIITV: TOwatts receive
(45 watts HEATER OFF)
320 watts tansinit (max)
DE ILS Vs SA receive
(TA HEATER OFF)
2A transmit (max)
(FT9018)
AC IITV: 55 watts receive
(4S wats EATER OFF)
105 watts tansmmit (max)
DC IRS V: 3K A receive
(08 A HEATER OFF)
7.5.8 transmit (mux)
Size
342 (W) x 154 (HD) x 324 (0D) mm
Weight:
Ike
TRANSMITTER
Emission:
LSB, USB (AR). CW CAT), AM (ASD), FM.
(£3) (option FT-901SD/DE). FSK (1)
PA input power:
FT-901DM/D/DE
SSB/CW. 180 watts DC
AN/ESK/FM. 0 watts DC
F901sD
SSB/CW/FSK/FM: 20.watts DC
aN. S watts DC
Carrer suppression:
Better than 40 db
wanted sideband suppression:
Better than 40.48 1000 He
Spurious radiation:
etter than 40 UR below rated output
‘Transmitter frequency response
300-2700 He (~6 db)
‘Third order distortion produets:
Beiter than 31 dB below rated ourput
‘Transmitter frequency stability
tess thin 300 Hp after 10 exinute wasmup,
fess
than
100
1b
after
30
minute
wartnup,
Negative feedback:
dB at 14 MHZ
Modulation:
ABE: Balanced mods
ABI: Amplitude modulation of « low power
Pa: Variable-reacta
© frequeney. moguls
tion, mas. deviation #5 kH2 (F3 fea:
ture optional on FT-9O1SD/DE)
Antenna output impedance:
50-15 Ohms. unbalanced
Microphone input impedance:
500 - 600 Ohms

RECEIVER
Sensitivity
SSBICW/FSK
0.25
4V
for
SIN
10
dB
AM
TAY
for
SIN
1048
a
0.3
AV
for
20 48
gvieting
Image rejection:
18-21 Miz Better than 60.48
28 Mila -- Better than SOaD
IF rejection
‘etter than 70 dB
‘Selectivity, WIDTH control at “0
SSB: —60B/2.4kI2 60 dB/4.0 kHz
CW: 6 UB/O.6 KHz 60 0B/1.2 Hz
TAM: —6 dB/6.0kH2 60 dB/12.0kHr
AEM: 68/120 kHz -60.dB/24,0 kH2
AM and CW filters are optional all models
**EM UNIT optional on FT-901SD/DE.
Passband toning:
‘Continuous from 2.4 kHe. 10 300 He
Intermodulation
Better than 80 UB jmmunity at 20 kite offset
20.48 mpuis at 14 Mttz
Desensitization:
Better than 100 JB immunity at 20 kM? off
20 dD input at 14 MItz
APF response
Within 3 eB from 400 - 900 Hz
Audio outpur:
Better than 3 watts @ 10% THD
Audio output impedance:
4-16 0hms
FT-901D/SD/DE/OM MODEL DIFFERENCES
Buitein feature
X= Available option
i FEATURE [F801 | Frs0is0 | Frsoine | Freoion]
[Bano caYsTAt 160m [0 ° | o °
BAND CRYSTAL 80m ° ° 2 ©
BAND CRYSTAL 40m © 9 @ °
BAND CRYSTAL 16m 3 6 5 ©
BAND CRYSTAL 10mA -_: ° ° °
BAND CRYSTAL 108 ql 3 © ©
BAND CRYSTAL 10m © © 5 ©
[BAND cAYSTAL _—10n0 © ° © 5
BAND CRYSTAL WWV/UY RCV © om © oJ
VOXIWARKER UNIT ° ° e o |
[em unit ° x x 2
RF SPEEGH PROCESSOR oe 70 ° 6
[aM FILTER x x x 7]
OW FILTER x x x =
EYER UNIT x x 3 3
[MEMORY UNIT x x x o
COC CONVERTER x x x 3
COOLING FAN o x oO o
POWER OUTPUT Too w iow woow | T00w

“TUBE COMPLEMENT
12By7A 1
61468 2
SEMICONDUCTOR
COMPLEMENT
Germanium transistors:
T20A6 2
Silicon transistors
2SASGAA 2
28nei9 1
2sa733 4
DcsTY 3
2scs73, 10
28C535A
2SCTSSY 3
28C7850 5
28945 a
2sc1o00GR 5
28C1818GR 2
ascisisy 49
2Na827 1
MPSAI3 1
Ic
25KI9GR
2sKI9RL
2SK34E
38K40M
38K59Y
39KS9GR
110338
8083
PCTELOS
PCTSLOS
HPC14305
HPCI4308
wPciasi2
F4024cP
40192
LM308
MCI416P
MC3403P
Mcao4aP
(upc 1008)
MC 1401 1B
MC 140428
MMT4C90
MSLUSOY3
MSLOBOY4
MSMS61
MsMssor
MSM5562
MSM5364
SN754508
SN76S14N
SN74LSOON
SN74LO4N
SNT4LSOON
SNDALS]23N
SN7ILS192N
‘TATO60P
TATOGLAP
TA7063P
TA7059M
TA7205AP
TA7310P
‘Te5032P
1
1
1
1
1
a
1
Hl
5
'
1
1
1
'
Germanium diodes:
1N60
1S 188M
151007 (GB)
INTO)
Silicon diodes:
18158589
toot 7
top10 5
voos 2
Specifications subject to change without notice
Varactor diodes:
182209
182236 '
F C63 t
MVIog 10
Silicon vatistor diodes:
MVI3 t
Zener diodes:
wz0s0
Wz090
wzit0
Light-emitting diodes:
GD4-2038RD 11
Lightemitting display’
HPS082-7740 6

CONTROLS AND SWITCHES
This transceiver has been specifically designed for
ease of operation and versatility. The operator
may, however, be unfamiliar with the operation
of the controls, and improper adjustment thereof
may result in poor transceiver performance. Thus,
(1) MODE
The
MODE
switch
has
six
positions
for
selection
of
the
operating
mode
desired:
LSB,
USB,
CW,
FSK, AM, or FM.
(2)
The
REJECT-WIDTH
REJECT and WIDTH controls are mounted
on
concentric
shafts.
The
rejection
tuning
control
(REJECT),
when
activated
by
pressing
the
small
silver
pushbutton
left
the
REJECT
knob, provides a variable IF notch filter action
for
nulling
out
a
particular
interfering
signal
to the of
The WIDTH control varies the signal across the
passband
of
one
of
the
two
IF
8-pole
crystal
band-
pass filters used in this circuit, thus providing a
variable IF bandwidth for rejection of signals above
or below the desired signal.
(3) M
The M button is pressed to store a frequency in
the
memory
circuitry.
frequency
is
being read out on the digital display will be the
frequency stored when the M button is pushed.
Whatever
wy
7)
be certain that you understand the function of
every before operating the transceiver.
The various front panel controls and switches
are described in the following section.
control
®
(4) EXT
When pushed, the EXT button transfers frequency
control
from
the
FT-901DM
to
an
external
VFO,
such as the FV-901 fully synthesized scanning
VFO.
(5)
VFO
When the VFO button is pushed, frequency con-
trol is transfered from EXT or memory control to
the FT-901DM internal VFO.
(6) TX-MR-RX
Once a frequency has been stored by the memory
(M) button, that frequency may be recalled for
control of either the transmit or receive frequency
by pushing either the TX or RX MR button,
respectively.
(7)
MR
Once
a
frequency
has
been
stored
by
the
memory
(M)
button,
that
frequency
may
be
recalled
for
control
of
the
transceive
frequency
by
pushing
the MR button.

(8) PRESELECT
This control pretunes the signal cireuils for bath
transmit and receive. The PRESELECT circuit
Drowites continuous peemeability tuning through
‘ur the Frequency range of the bransecive
1) HAND,
Ihe BAND switch provides selection of the band
10 through 10 meters plus WWV/JIY
Arecrive nly
Uosire,
(10) RF GAIN/CLARIFIER
The RF GAIN und CLARIFIER controls are
hnowted on concentsic shafts, The RF GAIN
keonisol provides manual contro! of the gait eels
ff the RF and IF amplifies on receive,
‘The CLARIFIER control allows mana offset of
ELS Kllz of either the ttansmit oF receive tre
{queney. Selection of transmit oF reecive clarifier
ie hy the two silver pushbuttons to the
left of the CLARIFIER contol
an atr
The ATT (RF antequator) button provides inser
lion of 4 20 dB attenuator in the incoming signal
path fa minimize recviver cross modulation eaused
by extremely strong focal signa,
(12) PROC LEVELJAF GAIN
‘The PROC LEVEL and AF GAIN controls are
‘mounte on concentric shafts. The PROC LEVEL
contra! allows manual contro! of the outpat level
fof the RF speech processor. The processor is
actuated by pressing the silver pushbutton to the
left ofthe PROC LEVEL contrat
‘The AF GAIN control adjusis the audio output
level at the speaker and phone Jack. Clockwise
rotatinn increases the audio output
(13) TUNE
This pushbutton, when depressed, places the trans
milter inthe “Tune” condition for ten seconds
for tuning purposes. After ten seconds, the train
ceiver is returned to the receive mode so a to
al_ampitier mbes caused
‘ime
during
toneup.
prevent damage to the
by cxoessive “key down
(14) LOADING.
This control tunes the output eireuit of the ps net-
Work
to
match
the
antenna/feedtine
impedance.
(15) PLATE
This control tunes the plate circuit of the final
amplifier
(16) CALIB,
When the MARK switeh is activated, the CALIB
knob provides manual vontrol for zeroing the
calibration of the digital display with he eal
brator signal
(17) CARR/KEYER
The CARR and KEYER controls are mounted
fon concentric shafis. The CARR control varies
the amount of cartier in the CW, AM, FSK. and
FM models af operation
‘The KEVER contiol varies the speed of the
builtin Curtis 8043 IC electronic keyer,
(18) VOX GAIN
This control selects MOX/PTT/VOX transmitter
relay control as well as adjusting the sensitivity of
the
VOX
circuitry.
The
PIT
position
provides
pust-io-alk operation from 4 microphone PTT
switch oF a footswitch, The MOX position provides
‘manual transmit, It must be returned to the PTT
position
For
receiver
recovery
(19)
APF
FREQ.
‘This
knob,
when
actuated
by
cuming
on
the
APF
switch,
provides
manual
control
for
peaking
the
auitio
peak
filter
(APE)
citeuit
on
the
desited
signal.
This
control
witl
find
its
chief
wsefulness
‘on
CW.
because
is
bandwidth
is
much
tow
marrow
for
normal
SSB
reveption.
(20) SOLMIC GAIN
‘The SQL and MIC GAIN controls are mounted on
concentric shafts, The SOL control sets the squeleh
threshold level for FM reception,
‘The MIC GAIN control varies the audio lev! from
the microphone amplifier stage, The control has
sulficient range to permit the use of any low inv
edance (50 - 600 Ohm) erystal or dynamic
‘microphone.
Clockwise
rotation
increases
the
level
of
output
from
the
microphone
amplifier
stag,
(21) FUNCTION SWITCHES: AMGC, APF/MONI,
AGC, PO/IC/ALC, and NB/MARK
‘The
AMGC
switeh
activates
+
microphone
gain
threshold circuit which requires a particular

minimum input level from the microphone to
trigger
the
microphone
amplifier.
Low-level
back-
ground noise will not activate the transmitter
with
the
AMGC
in
operation.
This
circuit
may
be
considered
a
“microphone
squelch”
system.
The
M
GAIN
control
functions
normally
with
the
AMGC system in operation.
When
the
APF/MONI
switch
is
in
the
APF
posi-
tion,
the
audio
peak
filter
(APF)
circuitry
is
activated.
The
exact
frequency
of
the
audio
peak is set by the APF FREQ
knob.
When
this
switch
is
placed
in
the
MONI
position,
monitor-
ing
of
the
microphone
level
may
be
accomplished
for
operator
convenience
or
tape
recording
both
~
sides
of
a
QSO.
In
the
CW
mode,
CW
sidetone
will
be
heard
regardless
of
the
position
of
the
APEF/MONI
switch.
The
AGC
switch
controls
the
length
of
the
re-
covery
time
for
the
receiver
AGC
circuitry.
This
switch
provides
slow or fast recovery,
and will
also turn off the AGC if desired.
The PO/IC/ALC switch will hereafter be referred
to as the METER switch. In the PO position,
relative
transmitter
output
power
can
be
observed.
In the IC position, transmitter final amplifier
cathode current may be measured. In the ALC
position, transmitter ALC voltage may be read.
When the FT-901DM is in the receive mode, the
meter functions as an “S” meter.
The NB/MARK switch provides for actuation of
either the Noise Blanker (NB) or crystal calibrator
(MARK), The marker oscillator can produce cali-
bration signals at intervals of either 25 kHz or
100 kHz by proper positioning of a switch inside
the cabinet.
(22)
POWER
This is the main on/off switch for the transceiver.
In the OFF position, the memory circuits are
disabled, so that when the transceiver is turned to
ON again, the memory circuits will have to be
reset.
(23) HEATER
With the HEATER switch in the down position,
the transmitter tube heaters are turned off. This
reduces battery drain to 1.1 amp and thus permits
long periods of listening without excessive battery
drain. Placing this switch in the up position pro-
vides supply voltage to the tube heaters, and
after 30 seconds of warmup the transmitter is
ready\for operation. This switch operates in both
the AC and DC modes.
SS)
(24)
PHONES
This
is
a
standard
1/4”
phone
jack
for
accom-
modation
of
headphones.
The
internal
speaker
is
disabled
when
headphones
are
plugged
into
this
jack.
(25) MIC
This four-conductor jack
microphone
plug
for
microphone
input
as
well
as
for PTT actuation.
accommodates — the
Mic plug
Headphone plug

REAR
APRON
CONNECTIONS
O®
(1) GND
Threaded lug for ground connection. la
(2)
RF
OUT
Signal frequency output from the driver stage
may be obtained at this jack for use with optional
equipment, such as the FTV-901R VHF/UHF
transverter.
(3)
ANT
Coaxial connection for antenna.
(4)
POADJ
Sets PO meter sensitivity.
ond receiver receives its antenna connection
through thisjack.
ACC
Cessory socket. Provides access to transceiver
operating voltages and relay contacts.
—————
(7)
KEY
Three-conductor jack
paddle or external key.
for connection to keyer
(8) EXT VFO
Connections for external VFO.
OH/ODO®
w
7) \
5
———— a
“MU ( REC.)
(9)
FUSE
;
Fuse holder requires 5 amp fuse for 117 volt or
* 3 amp fuse for 220 volt operation. For 12 volt
DC operation, a 20 amp fuse
power
cable.
installed in the
When
replacing
fuses,
be
certain
to
install a fuse of the proper rating. The warranty
does not cover damage caused by improper fuse
replacement.
(10)
POWER
Power receptacle. Both AC and DC cables are
Std€tone output for second receiver (if used).
—
(12)
IF
OUT
2
Wide-bandwidth
8.9
MHz
IF
signal
for
connection
to a spectrum
analyzer,
ete.
(13) PATCH
Speech input terminal for phone patch connection,
Impedance is 500 ohms.
(14) A-PRIP
ntj-tfip
input
from
second
receiver
(if
used).
——
(15) SP
Audio
output
is
provided
at
this
jack
for
an
ex-
ternal speaker. Output impedance is 4 ohms, and