Technics ST-9038 User manual

Technrcs
O
ç
Guzr.n-rz Synthesizer
FM Stereo Tuner
s-T-903El
OPERATING INSTRUCTIONS
Before operating this unit, please read these instruclions completely.

-a)),,, 9',.o ,:%,
Your new "Technics" Quartz Synthesizer FM stereo
tuner was manufactured and assembled under
exacting quality control standards.
The incorporation of the latest advances in design
and the use of the most modern components assure
outstanding performance with superb sensitivity and
tonal quality.
A few minutes of your time, wisely spent reading
carefully through this instruction booklet, will assure
you of getting the maximum benefit of this fine
component's potential.
. PRODUCT SERVICE
. TECHNICAL SPECIFICATIONS
. FEATURES
o STEREO SYSTEM COMPONENTS AND THEIR
GoNNECT|ONS...
. FRONT PANEL CONTROLS AND THEIR
FUNCTIONS
. LISTENING TO RADIO BROADCASTS
. ANTENNAS
. USE OF THE FM MULTIPATH OUTPUT
TERMTNALS ...... +. .... I
. FOR LONG AND SAFE USE OF THIS UNIT...... 9
. MAINTENANCE OF EXTERNAL SOURFACES....lO
. ACCESSORTES ..10
. USE OF UNIT'S "FEET". .c2
. MOUNTING IN AN EIA-STANDARD RACK . .....C2
This unit should be serviced by qualified technicians only.
No service information is provided for customers.
Should your "Technics" product ever require servicing,
refer to the Directory of Authorized Service Centers or your
franchised "Technics" dealer for detailed instructions.
You will find the serial number located at the bottom of the
unit.
Frequency range 88.1 -107.9 MHz
Sensitivity 12.8 dBf (1.2 pV 75 O IHF '58)
50 dB quieting sens¡tlv¡ty
itoNO 18.1 dBf (2.2 ¡tv 75 o IHF 's8)
STEREO 38.1 dBf (22 ttY 75 O IHF '58)
Tolal harmonic dislortion (1 kHz)
MONO O.',lyo
STEREO 0.15Yo
s/N MONO 75 dB
Frequency response 20 Hz-18 kHz, *0.1, -0.5 dB
Allernate channel select¡v¡ty 75 dB
Caplure rallo 1.0 dB
lmage rejection at 98 MHz 95 dB
lF relection at 98 MHz 105 dB
Spurious response rejection at 98 MHz 105 dB
AM suppresslon 55 dB
Slereo separatlon ,
I kHz 45 dB
10 kHz 35 dB
Leak carrier
19 kHz -65 dB
Antenna lerminal 75 O (unbalanced)
F-type co-axial
Ouþul Yollage
Power consumplion
Power supply
Dimensions(W xH xD)
0-1.5 V (variable)
12W
60 Hz, 120 V AC
450 x53 x293 mm
(17æ" x2=32" x11#"1
5.9 kg (13.01b.)
Iteight
1
1
2
3
5
6
7
The model number of thís product may be found on the back of the unit; and the serial number on the label affixed
to the bottom. I
You should note the model and serial numbers of this unit ¡ry'the space provided, and retain this booklet as a
permanent record of your purchase to aid.in identification ifhe bvent of theft.
MODEL NUMBER SERIAL NUMBER
WARNING: ro pREvENr F¡RE oR sHocK HAZARD,
DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE.
-1---

This unit is a Quartz-Synthesizer FM Stereo Tuner especially
designed to ach¡eve an extremely high level of waveform
lidelity.
It was developed primarily with the concept of improving
the listener's enjoyment of music reproduction, not merely
as a component to receive radio broadcasts, and its design
features a great many points of improved opêralion.
Technics tuners are designed with one central concept
in mind:to bring the atmosphere of the concert hall to the
home listening room. This high-performance tuner ¡n-
corporates Technics' own original technological advances
in order to assure the highest order of waveform fidelity.
I'lg-Xttz Pilot-signal-Cancel Circuitry
The pilot-signal-cancel circu¡try used in this unit is
spec¡al circuitry originally invented by Technics' own
technology.
The 19-kHz pilot signal, unnecessary for audio repro-
duction, is cancelled by applying a waveform-shaped
.19-kHz signal to the multiplex input, making use of the
phase-locked-loop lC, thus resulting in a flat and wide
frequency response oÍ 2O Hz to 1B kHz (+0.1 dB, -0.5 dB).
I SAW (Surface Acoustic Wave) Filter Fo¡ Superb
lF Stage With "Group-Delay" Characteristic
The lF stage includes five stages of differential ampli-
fication w¡th superb limiting characteristics. lF filtering
is achieved by using two 4-resonator type ceramic
filters plus a special Surface Acoustic Wave filter with
independently selectable group-delay and amplification
characteristics. The arrangement of these f ilters
provides extremely sharp selectivity and an excellent
distortion ratio. This filtering arrangement is connected
with adjacent wide-band, low-distortion FM-detection
circuitry.
I Purely Electronic Front End
Five especially selected low-tolerance variable-
capacitance diodes are used in the front end, replacing
the conventional S-gang variable capacitor, and making
the f ront end purely electronic.
The design is particularly resistant to f requency
deviation and external interference, with 2 doubleluned
circuits which use "high Q" coils of excellent selectivity
and ¡nterference-exclusion characteristices, as well
as an RF amplifier w¡th a 4-pole MOSFET and a buffer
with a junctionlype FET through which the local
oscillator supplies the oscillation frequency to the
m¡xer.
QUARTZ SYNTHESIZER FOR PRECISE AND
EFFORTLESS TUNING
This tuner employs a "pure electronic" tuning system,
"locking in" the frequency by using a quartz synthesizer.
The most important leature of this synthesizer system is
the extremely precise tuning accuracy which it makes
possible.
By iaking advantage of the precise oscillation frequency
of the quartz crystal, the locked synthes¡zer system makes
automatic station selection possible with a simple fingertip
touch of one of the automatic-tuning pushbuttons. None of
the conventional tuner components such as tuning knob,
flywheel, dial scale indication needle, tun¡ng meter, etc.
are to be seen-and indeed are not needed! Tuning is
exceptionally precise and completely effortless!
Recept¡on f requencies are spaced at intervals of 0,2 Mf|z,
and frequency indication is by clearly read and extremely
precise d¡gital ind¡cation.
I Automatic Tuning And New Muting System For
Easy Stalion Selection
This unit takes full advantage of the extraordinary
features of the synthesizer system for automatic station
selection. The muting switch has 3 positions: "fine,"
"standard" and "off."
. The "fine" position can be used for broadcast re-
ception wìth a stereo distortion ratio of 0.20lo or less.
. The "standard" position can be used for broadcast
reception with a stereo distort¡on ratio of 1 o/o or less'
. The "off" position can be used for broadcast reception,
at 0,2 MHz intervals, of all broadcasts within the
f requency range of BB.1 to 107.9 MHz.
I High-Precision Quartz-Cryslal Oscillation
Element With No Secular Variation
ln order to obtain its especially high oscillation precision,
the quartz-crystal oscillation element used in this unit
has internal gold plating and ¡s constructed by using
special cold-welding techniques, in a vacuum, thus
avoiding secular changes and the effects ol solder gas.
I ts-p¡n "Bus Line" Connector For Remote
Control Of Internal Circuitry
This unit has a special 16-pin "bus-line" terminal on its
rear panel which, by using digital technology, makes
external (remote) control of tuning operations possible.
OTHER FEATURES
A special die-cast cabinet-the type cons¡dered to be ideal
for communications equipment-is used, thus giving it
excellent res¡stance to external impact shocks, as well as
providing superb hÌghJrequency interference and shielding
effects, and high-frequency stability.
Another important feature is the "pink-noise" generator,
ideal for making recording-level settings and easy checks
of the overall audio system
There is; moreover, an automatic high-blend function which
automatically operates, by switching on and off, to deliver
FM music with minimized no¡se interference.
- l-

FOR DIRECT CONNECTION TO THE AMPLIF¡ER
Tuner input terminals
..TUNER'
FM antenna terminal ("FM ANT")
Output terminals ("OUTPUT")
Level-adjustmenl control
("ouTPUT LEVEL")
This control is used to adjust the
output level of the signal from the
output terminals ("OUTPUT").
16-pin control signal line term¡nal FM multipath output terminals
("MULTIPATH OUT")
4-channel multiplex output
terminal ("FM 4CH MPX OUT")
This is the output terminal for
4-channel FM broadcasts expected
in the future.
FM special antenna
75O coaxial cable
FM stereo tuner ST-9038
Stereo pinlype cord
To "UNSWITCHED" AC outlet of
amplifiçr or directly to wall outlet
ïo AC outlet
.-*@
Pre/main amplifier
Record player Tape deck Speaker systems
x ln order to charge the battery used as a reserve power supply for the internal memory circuitry in the
event of a power failure, the power cord of the Technics ST-9038 should be connected to the "UNSWITCHED"
AC outlet of the ampl¡f¡er or directly to a wall outlet.
-3-

WHEN THIS UNIT IS USED TOGETHER WITH THE TECHNICS SH.9O38 PROGRAMMABLE UNIT
FM special antenna
75O coaxial cable
To "TUNER" terminal
of SH-9038
FM stereo tuner
sT-9038
(L)
Stereo pin-type cord
16-pin connect¡on cord
To AC outlet Programmable unit
(sH-e038)
(R)
{Tuner input terminals ("TUNER")
{Recording output terminals "REC OUT"
{ Playback terminals ("PLAYBACK")
(L)(Br (L) (Ri (L)(R) (L)(R) (L)(R)
Prelmain amplifier Ill
{To "AMP" terminal of SH-9038
{To "AC 1" terminal of SH-9038
lnput term¡nals
("L|NE rN")
FM antenna terminal ("FM ANT")
Output terminals
("ouTPUT")
16-pin control signal
line terminal
Tuner input terminals ("TUNER lN")
Tuner output terminals ("TUNER OUT")
Recording input terminals ("REG lN")
Second tape deck, etc. Recording output terminals ("REC OUT")
16-pin control signal
line terminal
Output terminals
("LtNE OUT")
Tape deck
,^-

ÍD Power-on/stand-by switch
Turns the secondary power of this unit on and off. The
unit is in the "stand-by" condition when th¡s switch is
set to the "Ó " position.
This switch controls the secondary power only; not the
primary power.
Ø Muting switch/station selector (station selector)
This switch is used to remove the "between-station
noise" characterist¡c of the FM broadcast band, and to
select the input signal strength to the tuner.
"fine":
At this position, broadcast s¡gnals with a stereo dis-
tortion ratio oÍ O.2Yo or less can be received.
Broadcasts can be automatically tuned by simply
pressing one of the automatic-tuning buttons @.
At this pos¡t¡on, the broadcast signals indicated by (d)
and (f) in the figure below would be received.
"standafd":
At this pos¡tion, broadcast s¡gnals with a stereo dis-
tortion ratio of 1 l;o or less can be received.
Operation is the same as for the "fine" position.
At this position, the broadcast signals indicated by (a),
(c), (d), (f) and (g) in the figure below would be re-
ceived.
"off":
At this position, all FM broadcast signals are received.
Set to this position when it is desired to receive even
weak signals with a stereo d¡stortion rat¡o of more
than 1%.
Note that the muting funct¡on is off at this posit¡on, and
therefore the volume control should be set to a low level
for tuning.
ln addition, although this is the "muting off" position,
the mut¡ng will function during tuning, becoming off
when the tuning is stopped.
@ Mode selector (mode)
The mode selector is used to change reception conditons
and to select the "pink-noise" generator used for
adjustment of the recording level, etc.
"pink noise":
When set to this posit¡on, "pink noise" will be emitted
from the output terminals ("OUTPUT").
When a flat frequency response ¡s indicated by the
meters, the modulation level is set for507o modulation.
For recording-level adlustment:
'. Using VU (level) meters
Adjust so that the indication needles show a reading
of about -6 VU (-6 dB).
. Using peak-level meters
Adjust so that the indication needles show a reading
of about +3 dB.
Because the optimum value is apt to vary according
to the program source and the tape deck, adiustment
of the recording level shor{d be made by taking such
factors ¡nto considerat¡on.
"auto":
' Stereo broadcasts will automatically be received as
stereo, and monaural broadcasts w¡ll be leceived
monau rally.
ttmonott:
All broadcasts, stereo and monaural, will always be
received monaurally.
G) Automatic high-blend sw¡tch (auto hi-blend)
When this switch is set to the "on" position, the high-
blend circuitry will function automatically, turning on
and off depending upon the strength of the input signal.
The switch is off when pressed inward (l^¡)' and
on when released outward (^-r).
The high-blend circuitry operates to reduce noise,
without acoustically disturbing the stereo effect' by
mixing the left and right high-frequency range, where
noise is relatively more ¡rr¡tat¡ng to the ear.
@ Frequency display
The frequency being received is indicated by illuminated
digits.
There is, in addtion, a stereo indicator in the upper left
part to indicate that a stereo broadcast is being received.
-5-
88.1 90.1 92.1 94.1 96.1 98.1 100.1 102.1
frequency (MHz)
-
o
Þ
c
oîl

@ Automatic-tun¡ng buttons (auto tuning)
The button marked "up" should be pressed to tune to
a higher frequency, and the button marked 'ldown" to
tune to a lower f requency.
Ø Manual tuning conlrol (manual tuning)
Use the manual tuning control for manual selection ot
the desired broadcast frequency.
FEA OF swrTc /STATION
SELECTOR ø
The muting switch/statíon selector @ of this unit has 3
position sett¡ngs in order to take maximum advantage of
the features of the quartz-synthesizer system used in this
unit.
By simply pressing one of the automat¡c-tuning buttons,
this unit automatically selects the broadcast station, a
feature not found on conventional tuners with the dial{uning
system.
The unit is also designed so that unwanted frequencies
are not received, if so desired because of signal con-
ditions.
. The "fine" position can be used for broadcast reception
w¡th a stereo d¡stort¡on ratio of 0.2o% or less.
. The "standard" position can be used for broadcast
reception w¡th a stereo distortion ratio of 1 7o or less.
. The "off" position can be used for reception, at 0,2 MHz
intervals, of all broadcasts within the frequency range
of BB.1 to 107.9 MHz.
The selection among the 3 positions should be made,
therefore, depending upon the condition of the broadcast
signal to be received.
. lf local stat¡ons cannot be received at the "f¡ne" position.
Either there is a problem with the installation position of
the antenna, or the signal can't be received because ¡t
is from a distant station, or recept¡on conditions are
made difficult by nearby mountains, buildings, etc.
1) Although the d¡splayed indications all return to zero,
and thus are not "remembered," for ordinary electronic
calculators, etc., th¡s un¡t employs a back-up power
supply which makes it possible to retain information in
the memory circuitry. This means that this circuit can
thus "remember" which broadcast station the unit was
receiving ¡mmediately pr¡or to the power being turned
off, and, when the power is subsequently turned on,
the same broadcast station will be received. This feature
is known as the "last-station-tuned" memory.
2) This unit charges the back-up battery used for the
internal "last-station-tuned" memory circuitry. For this
reason, it is important that the power cord of this unit
be connected either to the "UNSWITCHED" AC outlet
on the rear panel of the amplifier or directly to a warl
outlet.
3) Because the battery may be discharged when the unit is
purchased, it should be charged, as described above,
for 2 or 3 days. Charging will continue no matter whether
the power switch is on or off.
4) Although there ¡s no problem if this unit is connected
to the Technics SH-9038 Programmable Unit, if this
unit is connected to an ordinary audio timer, the battery
will be charged only during "on" operation of the timer'
possibly resulting in insufficient charg¡ng and abnormal
operation of the "last-stat¡on-tuned" memory circuitry.
(lf this occurs, it should not of course be considered as
a malfunction of this unit.) t
D
..LAST.STATION.TUNED'' MEMORY AN
BACK-UP POIIIIER,SUPPLV: :i,:
Begin operation of the various components only after first
confirming that all connections have been made correctfy.
I Amplifier operat¡on
. lnput selector. . "tuner"
. Tape-mon¡tor switch. .."source"
. Speakerselector ....."MAIN" or"REMOTE"
. Volume control "minimum"
.Powerswitch. ........"on"
I Operalion of this unit
. Level-adjustment control (rear panel)...... .."'10"
. Power-on/stand-byswitch @ ... -... -"on"
' Mutins :ii::1:li'::: ïl;:':i,3""dard,, or .,off,,
. Mode selector @ .... ."auto" or "mono"
. Automatic-tuning buttons @ or manual tuning
control O........push "up" or "down", or rotate
. After tuning is completed, set the volume control of
the amplifier to the desired level.
. Using the level-adjustment control on the rear panel
of this unit, adjust the level of the input to the amplifier
so that it is the same level as the levels from other
input sou rces.
. For operation of the amplifier, carefully read its oper-
ation instructions.
. lf, when Iistening to a broadcast, there is much noise,
making pleasant reception difficult, refer to the section
..FM ANTENNAS'"
6

For best recept¡on of FM broadcasts, select an FM antenna
with the best characteristics for the area in which the unit
is to be used.
I lncluded antenna
The included antenna is easy to ¡nstall and is suggested for
use until a permanent antenna is installed especially for
FM. An antenna especially for FM should be installed in
order to obtain the best reception characteristics of which
this unit is caPable.
I Antenna exclus¡vely for FM reception
1) Selection
1. ln areas where very strong broadcast signals are re-
ceived (where the transm¡tting antenna can be seen),
use an outside antenna w¡th 3-5 elements.
Where signals are strong:
an antenna with 3-5 elements
2. ln areas where weak broadcast s¡gnals are received
(in mountainous regions or between tall buildings),
use an outside antenna with 5 elements or more.
Where signals are weak:
an antenna w¡th 5 elements or more
Note:
Consult with your dealer for detailed advice concerning
the number of elements the antenna should have.
2) Connection wire from the antenna
To obtain the best performance of whích this unit is
capable, the cable used to connect this unit with the
special antenna for FM reception should be 75O coaxial
cable (type RG-59/U or equivalent) which res¡sts the
effects of external noise.
3) lmpedance matching
lf it ¡s impossible to make a d¡rect connection with 75O
coax¡al cable from the antenna, a matching transformer
should be installed, as close to the antenna itself as pos-
sible.
300Q parallel-
Teeoer wtre 75()
coaxial
Matching
transformer
(300o-75o) cabl
4) Connect¡on
1. Prepare the 75O coaxial cable.
Connect¡on:
@ Prepare coaxial
cable (large or
small), radio pliers,
and a sharp blade.
@ Strip off about 15
mm of the coaxial
cable cover.
mri(1?")1
+Mesh wirc t
75o coaxial cable
Coax¡âl cablê cover
@ Cut away all except
about 3 mm of the
mesh wire.
@ Fit the F{ype plug
onto the coaxial
cable, inserting it
between the mesh
wire and the core
wire cover.
Mesh wire
Core wire cover
F-type plug
Use the plug which
corresponds with
cable thickness.
. F-tyæ plug: Large
3 mm (å")
Core w¡re cover
@ Place the ring over
the coaxial cable
to fit its thickness,
and spread out the
mesh w¡re.
@
@ Str¡p off about 3
mm of the core
wire cover, expos-
ing the core wire. t'
I f*smm(t") ro fir-
.F-type plug : Small
@ Use the radio pliers
to crimp the ring.
R¡ng
Rad¡o plier
*0)
t
Mesh wire: túrñ back Ring (included)
2. Connect the 75O coaxial cable to the "FM ANT 75O
COAXIAL" terminal of this unit.
75O coaxial
cable /
F-type plug
-7-

5) Locat¡on of anlenna
lnstall the antenna:
1. Where it will receive FM broadcast signals directly;
not in the "shadow" of a building.
Correct location avoids
mult¡path reception.
Direct
Obstruction
Reflected waves
Transmitt¡ng station
waves
Directional
characteristic Reflected
waves don't
enter
directional
range.
Note:
Multipath recept¡on is the distortion which results
from the reception of two types of s¡gnals: those re-
flected from nearby buildings, mounta¡ns, etc., and
those received directly from the broadcasting stat¡on.
2. Away from busy roads, and away from neon s¡gns.
ln order to receive FM broadcasts in the best possible
condition, it is necessary to use a special antenna
exclus¡vely for FM recept¡on, installing ¡t facing ¡n the
direction of least mult¡path distortion.
Multipath distortion can be .detected by using the multi-
path output terminals ("MULTIPATH OUT") as described
below.
I Simpte method, us¡ng a stereo ampl¡faer:
Make connection between the "VERT" terminal of th¡s
unit and one of the "AUX" terminals of the stereo
amplifier.
1. Tune to the FM broadcast.
2. Operate the stereo amplifier so as to get an aud¡o
signal.
3. Move the antenna about, and secure ¡t where the audio
signal is minimum.
This is the pos¡tion of least multi-path distortion.
crc
@Mrc
Connect to either
the left ("L") or right
("R") terminal.
VERT
terminal Stereo pin- AUX
type cord terminal
Stereo amplifier
I Method by using an osc¡lloscope
Make connections between the {erminal marked "HORIZ"
of this unit and the same terminàl of the oscilloscope, and
between the terminal marked "VERT'I of this unit and the
same term¡nal of the osc¡lloscope.
1. Tune to the desired FM broadcast.
2. Obtain the multi-path wavelorm on the oscifloscope
scfeen.
3. lf there is multi-path distortion, a waveform such as
shown ín "8" in the figure below will appear.
lf this type of waveform appears, move the antenna about,
and secure it in the pos¡t¡on where a waveform such as
shown by "A" in the figure below appears.
The waveform shown by "4" in the figure below indicates
the antenna position where multipath distortion is
minimized.
^
Away f rom noise sources!
3. At least am (13 ft.) above the ground (except in moun-
tainous regions, etc.).
rrrt ,As high as
possíble
Signals not
received if too
low.
4. At least 3m (10 ft.) away from a metal roof or other an-
tennas.
Metal roof
At least 3m
(10 ft.) away I
il
Danger close to power lines
^t
ry
o
o
o
ffi
No mult¡path distort¡on Multipath distort¡on exists
oscilloscope
n
il
m¡¡rfi¡lt
m
-8-
5. To avoid danger, away from electric power lines.

1) USE AN ORDINARY HOUSEHOLD AC POWER
SOURCE
I Use from an AC power source of high voltage,
such as for air conditioners, is very dangerous.
Be extremely careful not to make a connect¡on to the
electrical outlet for a large air conditioner or central-
heating unit which uses high voltage, because there is
the possibility of fire.
I A DC power source cannol be used.
Be sure to check the power source carefully, especially
on a ship or other place where DC is used.
DC
I lltlet hands are dangerous.
A dangerous electric shock may result if the plug is
touched by wet hands.
I Don't pull the power cord.
Always grasp the plug; never pull the cord itself.
A serious electric shock might occur if this unit is repaired,
disassembled or reconstructed by unauthorized persons,
or if the internal parts are accidently touched.
Never permit children to put anything, especially metal,
inside this unit. A serious electric shock or malfunction
could occur if articles such as coins, needles, screw-.
dr¡vers, etc. are inserted through the ventilation holes, etc.
of this unit.
5) TURN OFF AFTER USE
lf the unit is left for a long time with ihe power on, this will
not only shorten its useful operat¡on life, but may also cause
other unexpected trouble.
6) ¡F WATER lS SPILLED ON.THE UNIT
Be extremely careful if water is spilled on the unit, because
a f¡re or serious electric shock might occur. lmmediately
disconnect the power cord plug, and consult with your
dealer.
7) PLACE THE UN|T WHERE rr WILL BE WELL
VENTILATED, AND AWAY FROM DIRECT
SUNLIGHT
Place th¡s unit at least 10 cm (4") away f rom wall surfaces,
etc., and away f rom direct sunlight. Be careful that curtains
and similar materials do not obstruct the ventilation holes.
8) KEEP THE UNIT AWAY FROM STOVES, ETC.
Heat can damage the external surfaces as well as internal
circuits and components.
t
OF THE
CONNECTI ANDON
e
ROR
x\\
-9-