Panasonic SC-H M900 Service Manual page 21

[
SC-HM900
---
12.1.3 Bias and Erase Voltage
Check
12.1.4 Bias Frequency Adjust-
ment (Deck 1/2)
1.
2.
Set the "AUX" position.
Insert the Normal blank tape (OllCRA) into DECK 2
and the unit to "REC" mode (use" REC/STOP" key).
Measure and make sure that the output is within the
standard value.
Insert the CrO2 tape (OllCRX).
Repeat step 2 and 3.
1.
2.
Set the unit to "AUX" position.
Insert the Normal blank tape (OllCRA) into DECK 2
and set the unit to "REC" mode (use" REC/STOP"
key).
Adjust L1002 so that the output trequency is withing
the standard value.
3.
3.
4.
5.
Bias voltage tor Deck 2 14 :t 4 mV (normal)
17:t 5 mV (CrO2)
Erase voltage tor Deck 2 more than 80 mV (normal)
more than 90 mV (CrO2)
¡Standard Value:
97 :t8 kHzl
UNIT
r'
lIIllJ
+
_O
(GND)
Dlgltaltrequency
counter
r
12.2 Tuner Section
12.2.1 AM-IF Alignment
AM-IF ALlGNMENT
,-
AM-RF ALlGNMENT
r-
- 21-
Bias
T
:r.
Erase
ACEVM
UNIT
rm
1KQ
r=l
TP4
BDI
(GND)
-
1118
SIGNAL GENERATOR OR SWEEP
RADIO DIAL SETTING INDICATOR
ADJUSTMENT(Showin
REMARKS
GENERATOR
(ELECTRONIC Fig. 3)
CONNECTIONS FREQUENCY
VOLTMETER
OSCILLOSCOPE)
Fashion a loop 01
450 kHz30% Mod. Point 01non-
Headphone Jack (32 n)
Z102 (AM 1FT) Adjustlor maximum
several turns 01 wire
at 400 Hz.
interference (on/about Fabricate the plug as
output.
and radiate signal
600 kHz) shown in Fig. 2 and then
into loop 01 receiver
connect the lead wires 01
the plug to the
measuring Instrument.
SIGNAL GENERATOR OR SWEEP
RADIO DIAL SETTING INDICATOR
ADJUSTMENT (Show in
REMARKS
GENERATOR
(ELECTRONIC
Fig. 1)
CONNECTIONS
FREQUENCY
VOLTMETER
OSCILLOSCOPE)
Fashion a loop 01
520 kHz
Tuning capacitar lully Headphone Jack (32 n)
Z101 (AMOSC Coil) Adjustlormaximum
several turns 01 wire closed
Fabricate the plug as
output.
and radiate signal shown in Fig. 2 and then
into loop 01 receiver
connect the lead wires 01
the plug to the
measunng instrument.
Fashion a loop 01
600 kHz
Tuning capacitar lully Headphone Jack (32 n)
Z101 (AMANTCoil)
Adjustlormaximum
several turns 01 wire open Fabricate the plug as
output.
and radiate signal
shown in Fig. 2 and then
into loop 01 receiver
connect the lead wires 01
the plug to the
measurir.g Instrument.