Technics ST-7300 Service Manual

= ALIGNMENT INSTRUCTIONS
10
11
12
[Apply about 100dB (0.1V)
Notes:
1. Selector switch ..... AM (AM Alignment) 4. Output of signal generator should be no higher than necessary
FM (FM Alignment) to obtain an output reading
2. Muting/FM mode ... off/FM mono 5. 30092 FMdummy antenna..... Refer to fig. 4
3. Maintain line voltage at rated voltage
AM/FM SIGNAL GENERATOR DIAL INDICATOR ADJUSTMENT
CONNECTION FREQUENCY (DISTORTION METER)
AM ALIGNMENT
455kHz
(30% Mod.
AM signal generator high with 400Hz) | Point of non- Connect VTVM or scope. . T201 (ist FT) Adjust for maximum
rt through 0.0014 ‘A to | [Set for inter-ference (L sa res oe 1202 (2nd IFT) output.
antenna terminal. England ee a T203 (3rd IFT)
to 470kHz!]
Fashion loop of several’ 600kHz Connect VTVM or scope Adjust for maximum
turns of wire and radiate (30% Mod. 600kHz to output terminal L203 (OSC Coil) output. Adjust L201
signal into loop of tuner. with 400Hz) (L or R) of set. L201 (ANT Coil) by moving coil bobbin
along ferrite core.
Fashion loop of several 1500kHz Connect VTVM or scope ’ Adjust for maximum
i turns of wire and radiate (30% Mod. 1500kHz to output terminal a te output.
signal
into
loop
of
tuner.
with
400Hz)
|
(L
or
R)
of
set
Repeat
steps
(2)
and
(3)
; FM IF ALIGNMENT
: 6 at Adjust for center of
Point
of
non-
;
T101
(Discri
1FT)
:
eas
|
noses
inter-ference
|
[uning
meter
of
set
Primary
[Al
|
—
meter
inet:
Connect FM signal gene-
rator to 3002] FM antenna SOMHz
terminals through FM
dummy antenna.
illite a en ae 106MHz Connect VTVM or scope CT3 (OSC Trimmer) Adjust for maximum
farminals throuch:EM (100% Mod. 106MHz to output terminal (L or R) CT2 (DET Trimmer) output. Repeat
auiancen Abescs with 400Hz) or TP101 of set CT1 (ANT Trimmer) steps (5) and (6)
Connect VTVM or scope 3 (OSC Coil) ‘ as
(100% Mod. 90MHz to output terminal (L or R) L2 (DET Coil) Adjust for maximum
with 400Hz) or TP101 of set L1 (ANT Coil) output.
FM MONO DISTORTION ALIGNMENT
Connect distortion meter
to cutput terminal
(L or R) of set.
Connect FM signal gene-
rator to 3002 FM antenna aay as 100MHz
with 400Hz)
Tuning at 100MHz
and adjust for mini-
mum distortion.
Repeat steps (4) and (7)
T101 (Discri !FT)
Secondary [B]
terminals through FM
dummy antenna
FM SIGNAL METER ALIGNMENT
100MHz
FM MUTING LEVEL ALIGNMENT
100MHz
FM MPX PILOT ALIGNMENT
Connect FM signal gene-
rator
to
300
FM
antenna
bon
isd
Adjust
VR102
to
about
with
400H2)
Signal
meter
of
set.
“47”
on
signal
FM dummy antenna. meter scale.
Connect FM signal gene-
rator to 3002 FM antenna
.
100MHz
Connect
VTVM
or
Muting
switch
to
ON.
eee
ne
(100%
Mod.
scope
to
output
Adjust
so
that
output
/
mg
with
400Hz)
terminal
(L
or
R)
of
set.
can
be
obtained.
13dB (4.54V) to set. SG
indication are 25 dB (IHF)
Using a frequency counter
1. 98MHz Non-modulated mono signal applied to set.
2. Muting/FM mode switch to’’on/FM auto”.
3. Connect frequency counter to TP301 through resistor (100k).
4 Adjust VR301 to 19kHz +30Hz.
Using alternate system
1. Apply stereo signal from generator or stereo station to tuner.
2. Adjust VR301 until stereo indicator lights up.
Cement arm of VR301 as shown in fig. 5.
STEREO SEPARATION ALIGNMENT
Notes:
1.
Stereo
modulator
...........
Connect
stereo
modulator
output
to
EXT.
MOD,
terminal
of
signal
generator.
Internal
OSC
.....
1kHz
Pilot
signal
modulation
..........
10%
2.
FM
signal
generator..........
Frequency
approximately
98MHz.
Output
level
to
72dB
(IHF)
Modulation
mode
to
FM
3.
Band
selector
switch
.........
FM
4.
Muting/FM
mode
switch.....
on/FM
auto
INDICATOR
(VTVM or SCOPE)
Connect VTVM or scope to
output terminals through low pass
filter. Refer to fig. 6.
RECORDING CHECK LEVEL OUTPUT ALIGNMENT
@
FM
muting
/
mode
switch
to
on/FM
auto.
@
Reduce
recording
level
check
switch
to
ON.
@)
Apply
60dB
100MHz(400Hz
modulation)
stereo
signal
to
set.
@ AF
signal
level
at
OUTPUT
terminal
should
then be
OdB.
ADJUSTMENT
POINT REMARK
Adjust for minimum
right (and left) output
STEREO MODULATOR
MODE AND MOD. RATE
L (and R)
30% Modulation
FM SIGNAL GENERATOR
CONNECTION
3002 FM antenna terminals
through FM dummy antenna
VR402
( Adjust VR401 so that the output is then 6dB
less than the previous output.
ST-7300
aan. <a. a -
2 ee eee et oe ata

Technics ST-7300 Specifications

General

Brand	Technics
Model	ST-7300
Category	Tuner
Language	English