Yaesu FV-901DM User manual

INSTRUCTION
MANUAL
FV-901DM
| ae
YAESU MUSEN CO., LTD.
TOKYO JAPAN

SYNTHESIZED SCANNING VFO
FV-901DM
GENERAL DESCRIPTION
The FV-901DM external VFO for the FT-901 se: of transceivers provides a new dimen-
sion in operating versatility. Featuring PLL synthesis in 100 Hz steps, the FV-901DM may
be tuned by means of the main dial, or via manual or automatic scanning controls. As well,
the operator may select from as many as 40 positions of frequency memory, programmed
by a front panel pushbutton. A memory backup feature allows the memorized frequencies
to be held even though the VFO and transceiver are turned off.
Frequency control may be exercised in a variety of combinations, using the FT-901DM
main dial, the FT-901DM memory circuitry, the FV-901DM main dial, and the FV-901DM
memory bank. Any of these components may be selected to provide control of the trans-
mit, receive, or transceive frequency. A clarifier control on the front panel of the FV-
901DM allows precise tuning between the 100 Hz synthesizer steps, or to follow a drift-
ing signal stored in memory.
The following pages will describe in detail the operation of the FV-901DM synthesized
scanning VFO. As this apparatus is significantly advanced over other VFO’s on the market,
the operator is urged to read this manual thoroughly before attempting operation.

Frequency range
Output level
Stability (+ 25°C)
Memory channels
Clarifier
Power requirements :
Power consumption :
Case size
Weight
1) AC Power Cord
2) Connection Cable
3) Ground Cable
4) Fuse (0.5 A)
: 40
SPECIFICATIONS
5.55—4.95 MHz
150 mV RMS into 50 ohms
+ 300 Hz in first hour after | minute warm-up
+ 50 Hz after | hour
+ | kHz over temperature range —10°C — +60°C
+2.5 kHz offset of transmit, receive, or transceive frequencies, on dial or
memory mode
100/110/117/200/220/234 volts AC, 50/60 Hz 13.5 volts DC, negative ground
(use only optional DC cable)
AC — 13 VA (5.4 VA memory backup mode)
DC — 0.53 amps (0.12 amps memory backup mode)
210(W) x 154(H) x 320(D) mm
Approx. 4 kg.
ACCESSORIES
PIN No
1 VFO OUT-
2 GND—
3 EXT OVIN
4 AGC IN
STKI2VIN
ce |

CONTROLS AND SWITCHES
(1) MEMORY CHANNEL
The MEMORY CHANNEL selector switch chooses
up to 40 frequencies stored by the M_ button.
These frequencies can be used for control of the
transmit. receive, or transceive frequency, as
described in the “Operation” section.
(2) POWER
This is the main power switch for the VFO.
(3) MA
JAL SCAN switches
These switches select the scanning rate for the
PLL seanner. When activated, they will select
slow, medium, or fast scanning rate. depending
on the desires of the operator.
(4) AUTO SCAN
The automatic scanner will, when activated. scan
at the medium speed until a signal is received.
then stop. This feature is very useful for checking
a band for activity.
(5) TUNING DIAL
This is the main manual tuning dial for the FV-
9YOIDM. When control is said to be by the “FV-
901IDM VFO." it) should be understood that
control is by the PV-90LDM main tuning dial.
(6) SELECT switches
These switches determine the operating mode of
the FV-901DM.
Q ao a
MR is used for recall of a memorized fre-
quency for control of the tranceive fre-
quency.
TX MR is used for recall of a memorized
frequency for control of the transmit. fre-
quency, with receive frequency control
being on the main tuning dial
RX MR is used for recall of a memorized
frequency for control of the receive fre-
quency. with transmit) frequency control
being on the main tuning dial.
VEO selects operation via the main tuning
dial or the scanning functions for control
of the transeeive frequency
LOCK is used in conjunction with the main
tuning dial, With the VFO button: pressed,
pressing the LOCK button will cause the
VFO frequency to be locked. regardless of
the setting of the dial A second press of
the LOCK button returns control to. the
main tuning dial.
M is a momentary switch for inserting a
frequency into one of the 40 memory po-
sitions.
(7) ANALOG READOUT
The main tuning dial uses an analog frequency
display. The major calibration markings represent

CONTROLS AND SWITCHES
(1) MEMORY CHANNEL
The
MEMORY
CHANNEL
selector
switch
chooses
up
to
40
frequencies
stored
by
the
M
button.
These
frequencies
can
be
used
for
control
of
the
as
transmit, receive, transceive
described in the “Operation” section.
or frequency.
(2) POWER
This is the main power switch for the VFO.
(3) MANUAL SCAN switches
These
PLI
slow.
switches select the scanning rate for the
When they will
fast scanning rate, depending
scanner, activated, select
medium, or
on the desires of the operator.
(4) AUTO SCAN
The automatic scanner will, when activated, scan
at the medium speed until a signal is received.
then stop. This feature is very useful for checking
a band for activity.
(5) TUNING DIAL
This is the main manual tuning dial for the PV-
901DM. When control is said to be by the “FY-
901DM VFO. it) should that
control is by the FV-901DM main tuning dial.
be understood
(6) SELECT switches
These switches determine the operating mode of
the FV-901DM.
@ do Ww
MR is used for recall of a memorized fre-
quency for control of the tranceive fre-
quency.
TX MR is used for recall of a memorized
frequency for control of the transmit fre-
quency, with receive frequency control
being on the main tuning dial.
RX MR is used for recall of a memorized
frequency for control of the reecive
queney, with frequency
being on the main tuning dial.
tre-
transmit control
VFO selects operation via the main tuning
dial or the scanning functions for control
of the transceive frequency.
LOCK is used in conjunction with the main
tuning dial. With the VFO button pressed.
the LOCK button the
VFO frequency to be locked, regardless of
the setting of the dial, A second press: of
the LOCK the
main tuning dial.
pressing will cause
button returns control to
M is a momentary switch for inserting a
frequency into one of the 40 memory po-
sitions.
(7)
ANALOG READOUT
The main tuning dial uses an analog frequency
display, The major calibration markings represent

INSTALLATION
The FV-90IDM may be situated almost any-
where in the operating room, depending on the
operator's preferences. However, excessively warm
locations, such as on top of an amplifier, should
be avoided, if only to allow proper air circulation
for the other equipment.
Ort
© 100/110 120
© 100]110 120
Connect the ground cable supplied with the PV-
901DM_ to the GND terminals of the FV-901DM
and the FT-901. Connect the interconnection
cable from the EXT VFO jack on the FT-901 to
the FV-901DM OUTPUT connector.
BEFORE CONNECTING THE POWER CORD
TO THE REAR APRON POWER CONNECTOR,
MAKE SURE THAT THE VOLTAGE SPECIFI-
CATION MARKED ON THE REAR APRON
MATCHES YOUR LOCAL SUPPLY VOLTAGE.
REFER TO THE DRAWING FOR THE APPRO-
PRIATE > TRANSFORMER CONNECTIONS
WHEN CHANGING SUPPLY VOLTAGES. WAR-
RANTY DOES NOT COVER DAMAGE CAUSED
BY IMPROPER APPLICATION OF SUPPLY
VOLTAGE.
Connect the power cable to the rear apron POW-
ER connector. Place the FV-901DM POWER switch
in the ON position, and the VFO is now ready
for operation.
Transformer Primary Wiring
Note:
When using the optional DC cable, please note
that the 2 amp fuse is located in the cable itself.
Do not replace the AC fuse on the rear apron of
the FV-901DM with a 2 amp fuse.

OPERATION
FOR THE PURPOSES OF THIS AND FOLLOW-
ING SECTIONS, THE READER IS ADVISED
THAT THE TERM “FT-901" SHALL APPLY
TO ANY AND ALL VERSIONS OF THE FT-90]
SERIES: FT-901DM/DE/SD/D. THE MEMORY
UNIT IS BUILT INTO THE -901DM, AND
IS OPTIONAL ON THE OTHER MODELS,
THE READER IS REFERRED TO THE FT-901
SERIES INSTRUCTION MANUAL FOR FUR-
THER CLARIFICATION OF THE DIFFER-
ENCES BETWEEN THESE MODELS. SIMI-
LARLY, THE FYV-901IDM SHALL HEREAFTER
BE REFERRED TO AS “FV-901." THESE
TERMS ARE ADOPTED IN THE INTEREST
OF BREVITY.
The operation of the FV-901 in conjunction with
the FT-901 adds several levels of operating flexi-
bility never before possible with a transceiver/
VFO combination. This added flexibility, how-
ever, contributes somewhat to the complexity
of the operating procedure. Until familiarity is
gained with the various operating modes possible
with the FV-901, the operator is urged to refer
to this manual for operating instructions. A quick
reference card is furnished for your convenience.
SCANNER OPERATION
The three MANUAL SCAN switches allow tuning
of the FV-901 at one of three rates. In the SLOW
mode, the tuning rate is | kHz per second. In the
MED (medium) mode, the rate is 17 kHz per
second, and in the FAST mode, the rate is 100
kHz per second.
With the FV-901 VFO or TX MR switch pressed,
RX control is normally via the main tuning dial.
Holding the manual scanning switches UP will
cause the frequency to scan upwards until the
switch is returned to the horizontal position.
Likewise, holding the switches DOWN will cause
the scanner to move the frequency lower.
The AUTO SCAN switch, when activated, will
sean in the selected direction until a signal is
heard, at which time it will stop and lock on that
frequency. Another press of the AUTO SCAN
button will cause the VFO to scan again, until
another signal is heard. The scan rate in the AUTO
SCAN mode is the same as in the MED mode,
that is, 17 kHz per second.
CLARIFIER OPERATION
The clarifier in the FV-901 serves two useful
purposes. First, it allows very fine tuning between
the 100 Hz synthesizer steps. Secondly, it allows
tracking of a memorized frequency, should the
signal being received begin to drift.
To activate the receive cla push the RX
button. To activate the TX clarifier, push the
TX button. For transceive clarifier operation,
push both clarifier buttons,
When either of the clarifier buttons is pushed,
the small light emitting diode will become illumi-
nated to indicate that the clarifier is in operation.
FY-901 OPERATION WITH THE FT-901
For the sake of clarity and brevity, the FV-901
SELECT buttons to be pressed will be circled,
and the FT-901 CT buttons to be pushed
will not be circled. Thus, when a sentence reads,
“Press EXT, MR, and PX MR),” the reader should
press EXT and MR on the FT-901, and TX MR
on the FV-901.
A useful method of confirming the transmit fre-
quency while learning to use the FV-901 is as
follows: place the FT-901 MIC GAIN and CARR
controls fully counter-clockwise, and place the
HEATER switch in the OFF position. Then, by
placing the VOX GAIN control in the MOX po-
sition (or otherwise activating the PTT circuitry),
the transmit frequency may be observed for
reference. This particularly valuable when
observing operation in the split mode (TX and
RX frequency control separate).
is

I. REVIEW OF FT-901 MEMORY
OPERATION
In order to explain the operation of the FV-901,
a review of the operating procedure of the FT-901
memory feature is necessary.
Depressing the M button allows storage of
a frequency in memory.
After storage of a frequency in memory.
the pressing of the MR button will recall
this frequency for control of the FT-901
transceive frequency.
In like fashion, pushing the TX MR button
recall the memorized frequency for
of the transmit frequency, with
receive control being on the main dial
will
control
Pushing the RX MR button will recall the
memorized frequency for control of the
frequency, with transmit control
being on the main tuning dial.
receive
Pushing the EXT button transfers frequency
control to the FV-901 on tranceive, receive.
or transmit when the MR. RX MR. or TX
MR buttons, respectively, are also pushed.
Il. TRANSCEIVE OPERATION USING THE
FV-901 (Figs. 1 and 2)
Refer to the insert, “FV-901 Operation Decision
Tree.” Taking the “Transceive” branth, we can
see that transceive operation may be controlled
from either the FT-901 or the FV-901. From the
previous section, in which we reviewed FT-901
operation, we further know that FT-901 trans-
be via either the FT-901 VFO
appropriate positions of the
are the bottom of
ceive control may
or memory. The
SELECT switches
the decision tree.
shown at
In order to transfer control from the FT-901 to
the FV-901, the EXT button is pressed. Then,
the FT-901 SELECT switches dealing with mem-
ory. ie. MR, TX MR, and RX MR, shift control
from the FT-901 to the FV-901 on transceive,
transmit, and receive, respectively. Pressing EXT
and VFO does not transfer control from the
FT-901 to the FV-901.
To transceive on the FV-901, press EXT and MR;
control is now by the FV-901. Now the decision
must be made as to whether the FV-901 VFO or
memory bank will control the frequency. To
start, pres: Now the main tuning dial on
the FV-90] ontrolling the transceive frequency.
As well, the scanners are operable: refer to page
6 for instructions on scanner operation.
In order to store a frequency in memory.
MEMORY CHANNEL to position
tune the dial to the desired frequency, and press
(™).To recall this frequency for transceive control,
press(@MR). Other frequencies may be memorized
by pushing(VFO). tuning in the desired station,
placing the MEMORY CHANNEL selector in
positions 2-20, pressing(M), and pressing (MR) for
recall.
switch
Before proceeding to the next case, the logical
sequence should be reviewed. Having made the
to operate transceive, decided to
operate with the FV-901 in control. Having de-
cided that the FV-901 was to control the f
quency, we decided between the VFO and the
memory bank. The appropriate positions of the
SELEC the bottom of
the decision tree.
decision we
switches are shown at
Il. SPLIT OPERATION USING THE FY-901
(Figs. | and 2)
Split operation, using the FT-901 VFO, FT-901
memory, or the FV-901 VFO or memory, makes
a number of interesting combinations possible.
Prectical applications of split operation will be
offered at the end of this discussion.
Split operation adds one more level of decision-
making to the logical process, but the procedure
is identical to that of the previous section, Funda-
mentally, the decision is made to receive on the
FT-901 or the FV-901, and from there control
is transferred according to the requirements of
the situation.
Following the decision tree, let us decide to
operate split. while receiving on the FV-901.
Push EXT. Further, let us decide that we will
listen on the FV-901 VFO, while transmitting
on the FT-901 VFO. Push RX MR: this will
transfer frequency control from the FT-901 to

the FV-901 on receive, with transmit control
remaining with the FT-901. Now we must select
the operating mode of the FV-901. PressCVFO)
to provide VFO control of the FV-901. However,
the button may also be pressed. The
reason is as follows: the EX MR)leaves the FV-
901 in the VFO mode on receive, and transfers
control to the memory bank on transmit. But
we already decided that transmit control was to
be by the FT-901 when we pressed RX MR,
Therefore, the “selection between (VFO) and@X_
MRis, in this case, trival.
Another example follows: Let us decide to re-
tive on the FT-901 VFO, and transmit on the
FV-901 memory bank. Following the decision
tree, press EXT and TX MR; this transfers fre-
quency control to the FV-901 transmit
(activate the MOX control to confirm this). Now
press (MR) and@PX_MR). Remember that control
has been relinquished by the FT-901 only on
transmit and thus the condition of the FV-901
on receive is irrelevant. As a result, we can press
(MR or CX MR) with identical results.
on
IV. PRACTICAL OPERATING EXAMPLES
(a) You are operating on 40 meter phone, listen-
ing for DX between 7050 and 7100 kHz,
while transmitting above 7150 kHz (oper-
ators outside the USA should reverse the
preceeding). Station DXIDX heard on
7095 kHz, listening at 7205 kHz.
is
Proceed as follows:
If you are tuning on the FT-901 VFO, mo-
mentarily press EXT and MR, and set the
FV-901 main dial to 7205 KHz. Next, push
or(RX MR). Return the FT-901 to
receive frequency control by pressing TX
MR, leaving the EXT button depressed.
If you were tuning initially on the FV-901
VFO, store DX1IDX’s frequency in memory
position 1 by pressing). Now tune the PV-
901
main
dial
to
7205
kHz
(the
FV-901
ICT s hould still be pressed),
and then press(RX_MR). Receive control will
be on the memory (7095 kHz) and transmit
control will be on the dial (7205 kHz),
To listen to the pile-up calling DXIDX on
(b)
(ce)
7205 kHz, press(VFO). Should DX1IDX
begin to drift in frequency. the RX clarifier
may activated to follow the
signal.
be unstable
You are net control station for a net meet-
ing on 14315 kHz. Stations call into the net,
then are moved off frequency, Prior to the
start of the net, store typical QSY frequen-
cies (14280, 14285, 14290, 14295, ete.) in
the FV-901 memory bank. The net control
station may then, quickly, de
or not a particular frequency is clear by press-
ing(RX_MR)and setting the MEMORY CHAN-
NEL switch appropriately. In this way, 41
frequencies could, potentially, be examined
by one station (40 memory frequencies plus
the VFO frequency).
rmine whether
You are operating in a DX contest, where a
number of desired stations are on the band
at the same time. If some of them do not
respond immediately to your call, or if they
are not acknowledging your call area, store
them in the FV-901 memory bank by push-
ing EXT and MR or RX MR for receive con-
trol on the FV-901, (VFO) for FV-901 main
dial tuning, and @D) for frequency storage.
Then, by pressing (MR) and setting the MEM-
ORY CHANNEL switch appropriately, the
various stations may be checked quickly.
Total exposure on the band thus. in-
Note that, even though a band
change is made in the meantime, the mem-
orized frequencies remain yalid upon return
to the band on which they were stored!
is,
creased,

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FT-901/FV-901 SELECT SWITCH POSITIONS
FOR FREQUENCY CONTROL
FREQUENCY CONTROL
TX
Fy-901
VFO
FV-90)
MEM