Stereo Vco Adjustment; Filter Adjustment; Separation Adjustment - Hitachi 36UX59B Service Manual

MSLXU
Sound modulation condition:
Noise reduction encoder: ON
Stereo signal;
@ R=O (L only), 300Hz, 30% modulation
(see note)
@ R=O (L only), 3kHz, 30% modulation
(see note)
Monaural signal;
@ Monaural, 400Hz, 100% modulation
(PRE-EN Off)
SAP signal;
@ SAP, 300Hz, 30% modulation (see note)
(2) Connect AC voltmeter Vo to IS01 pin @.
Use the AC voltmeter of Matsushita model
VP-95OC or equivalent.
(3) Apply +9V to 1501, 1402 (add +9V to pin @ and
12V to pin @ of PNH2 connector)
(4) Same as item 4-1 (1).
(5) Select adjustment code "A04"
Adiustment Procedure
(1) Select sound input @ and adjust the data "A04"
to Vo= 500mVrms-t-1OmVrms at IS01 pin @ .
4-3-2 Stereo VCO adjustment
Adjustment Preparation
(1) Same as items 4-3-l (3) and 4-l(1).
(2) Connect a frequency counter to IS01 pin 0. Use
1 :I Probe.
(Probe standard Rirl Ma, Ci I 15pF)
(3) Should be no signal in pin @ (ISOl).
(4) Connect capacitor (lOOpF/16v) as it is shown.
(5) Select adjustment code "A01 .'I
R103
0 IS01
CS06
100/.&F/l 6v
Adjustment Procedure
(1) Adjust the data "AOf" to set 15.73+0.1 KHz by
4) keys.
(2) Delete capacitor (1 OOpF/16v)
4-3-3 Filter Adjustment
Adjustment Preparation
(1) Set capacitor 100 ,~uF/16V as it is shown.
(2) Apply the signal to IS01 pin @ with the circuit as it
is shown.
@ SG output signal spec.
@ Frequency
f=l573kHz (Sine wave)
@Signal Level
V=l OOmVrms
(3) Connect an AC voltmeter or oscilloscope to IS01
pin @.
(4) Select adjustment code "A03."
Adjustment Procedure
(1) Adjust the data "A03" so that the voltage of IS01
@pin becomes minimum by q,, keys.
4-3-4 Separation Adjustment
(The adjustment of items 4-3-l and 4-3-3 must be
completed first)
Adiustment Preearation
(1) Use the same circuit as input level adjustment
4-3-l (1).
-
(2) Connect an AC voltmeter to IS01 pin ?!!.) or con-
nect an oscilloscope.
(3) Select adjustment code "A05" and set data
"0032".
Adiustment Procedure
(1) Select input signal 0 and select adjustment code
"A05". Adjust by d,, keys so that 300Hz level
becomes minimum (L separation adjustment)
(2) Select input signal @ and select adjustment code
"A06". Adjust by d,, keys so that 3KHz level
becomes minimum (H separation adjustment).
(3) Repeat (1) and (2). Adjustment precision:
within +ldB from minimum point.
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