Teleton TFS-70 Service Manual page 3

(c) Adjust cores of T105 & T1104 to obtain Figure 10.
ie a
t. at
Noise
Figure 10
Note: 1. Take the height of A & A' as long as possible.
2. Inequality of noise (See figure 11) is no good.
Figure 11
FM Tracking Adjustment (do not remove the tuner cover.)
5-1 Measuring Equipment
(a) FM Standard Signal Generator (include the pad)
(b) Output Meter (V.T.V.M.)
(c) Oscilloscope
(d) Distortion Meter
(e) Dummy Load 82 50W
5-2 Preparation of Adjustment
(a) Volume ---------- Max. Mode ------------ FM
(b) Measuring connection is as follows.
SP 82
3002 Pad
Pon ee Se
i <
1252
' |
502
FM Standard
Signal
Generator Z=5082
¢
Distor-
tion
Meter
0 9
tied oa
sp. OUT Dummy Load
Mod, 400Hz 75KHz Dev. SP. OUT
82
Figure 12
(c) TC101, TC102, TC103 and TC104 position are as follows.
@)
Figure 13
(d) Set VR201, VR202, VR203, VROO5 and VROO6 to me-
chanical center position.
(e) Set Pre-Setter to MANUAL.
5-3 Adjustment
5-3-1 Adjustment of Local Osc. Circuit
(a) Connect @ terminal of Voltmeter to VROO7 2 terminal,
and (-) terminal of Voltmeter to chassis.
(b) Set tuning to max. and adjust VROO5S for 8V Volt-
meter scale.
(c) Set tuning to min. frequency and adjust VROO6 for:
1.5V Voltmeter scale.
(d) Repeat step (b) and (c) several times. When step (b) and
(c) match, voltage adjustment is finished.
(e) Adjustment of tuning circuit
Adjustment Step 1
Frequency (S.G.) 87.5 MHz 104.5 MHz
Freq. Position -Min. frequency Max. frequency
Adjust point L102
Adjust for max. output.
Repeat step 1 and 2 several times. When step 1 and 2 match,
adjustment of the Local Osc. Circuit is ending.
5-3-2 Adjustment of Tuning Circuit
Frequency (S.G.) 90 MHz 102MHz
V.C. Position 90 MHz Tuning | 102 MHz Tuning
Position Position
Adjust Point T1101, T102, TC101, TC102,
T103 TC103
Adjustment of Meter, Muting, Tape Output Circuit
Note: Adjustment of Tape Output Circuit should be
done after MPX adjustment.
6-1 Adjustment of Meter
(a) Input 90 MHz (Mod. 400 Hz, 22.5 kHz Dev.) 32dB (Att.
scale), and adjust red and black cores of T202 for max.
Meter scale.
(b) Set S.G. Att. scale to 112dB, and adjust VR202 for 8
meter scale.
6-2 Adjustment of Muting Circuit
Input 90 MHz (Mod. 400 Hz, 22.5 kHz Dev.) 32cB (Att.
scale), and set Muting Switch "ON". Turn VR201
counterclockwise to end (mute the output), and turn
clockwise to the point of which the output wave appears,
then set the point of which turn clockwise slightly.
6-3 Adjustment of Tape Output Circuit
Input 90 MHz (Mod. 400 Hz, 22.5 kHz Dev.) 72dB (Att.
scale), and adjust VR203 for 45 mV output of TAPE
OUT.
Note: Insert 47k ohm resistor to TAPE OUT as sus-
pected load.
MPX Adjustment
7-1 Measuring Equipment
(a) FM Standard Signal Generator (S.G.)
(b) STEREO Signal Generator (MPX S.G.)
(c) V.T.V.M.
(d) Oscilloscope
(e) Counter
(f) Dummy Load 82 50W
7-2 Preparation of Adjustment
(a) Volume, Balance ----- Adjust output of L ch. and R ch.
for 500mmW (2V).
Mode ----- FM Others ----- Same as procedure 1-2.
(b) Measuring connection Is as follows:
SG PILOT-?7.5kHz
Den MAIN
+
SUB
be -Wyo wey earned ee Ve
0d 67.5kHz
1
A '
'. Terrninal@ a vem ton oe
ayy Sut pu 2CtOr
of MPXK 70 Sw,
PILOT 10%
MAIN 45%
4% Oo
Figure 14
(c) Adjust VR501 & VR502 to middle position.
7-3 Adjustment
(a) Set S.G. to 90 MHz (L+R) + PILOT 32 GB.
(b) Tune set to 90 MHz.
(c) Adjust Volume & Balance for 500mmW SP. output of
both channel.
(d) Select (L+R) of MPX S.G. to "SUB". (ST. lamp not light.)
(e) Adjust VR501 for max. and no-distortion ''SUB'' wave-
form.
(f) Set MPX S.G. to R signal, and Output Selector SW. to
L ch. (leakage of R signal appears on V.T.V.M.) Then,
adjust VR502 for min. leakage of R signal.
(g) Set MPX S.G. to L signal, and Output Selector SW. to
R ch. (leakage of L signal appears on V.T.V.M.) Then,
confirm that the leakage is within 2 dB for R-L.