Toshiba 27a50 Service Manual page 14

MTS ADJUSTMENT (FOR N5ES/N7S CHASSIS)
No. ITEM
1 ATTENUATOR
(ATT)
2 STEREO VCO
(STVC)
3 SAP VCO
(SAVC)
4 STEREO FILTER
(STRF)
5 SAP FILTER
(SAPF)
6 STEREO SEPARATION
(WBAN)
(SPEC)
INPUT SIGNAL
• 1kHz 30% mod. → ANT
terminal
• No signal
• 78.670kHz 147mVrms
→ pin 9 of H002
• Monaural signal → ANT
• 9.4kHz 600mVrm
→ pin 9 of H002
Monaural signal → ANT
• 88kHz 120mVrms
→ pin 9 of H002
• Monaural signal → ANT
• STEREO 300Hz R-channel
only → ANT
• STEREO 3kHz R-channel
only → ANT
– 14 –
ADJUSTMENT PROCEDURE
1. Connect rms meter to pin 12 of H002.
2. Display item ATT on screen.
3. Change data by VOLUME s/t buttons so
that output at pin 12 of H002 becomes value
as close as 142mVrms.
1. Display item STVC, and connect pin 9 of
H002 to ground.
2. Connect frequency counter to pin 12 of H002.
3. Change data by VOLUME s/t buttons so
that the reading of counter becomes value
as close as 4fH (62.936kHz).
1. Display item SAVC.
2. Change data by VOLUME s/t buttons so
that the data becomes in the center of range
for STA7=0 and STA8=1.
SAVC
XXH
STA7:0 STA8:1
1. Display item STRF on screen.
2. Change data by VOLUME s/t buttons so
that the data becomes in the center of range
for STA3=1.
STRF
XXH
STA3:1
1. Display item SAPF.
2. Change data by VOLUME s/t buttons so
that the data becomes in the center of range
for STA4=1.
SAPF
XXH
STA4:1
1. Select "STEREO" mode from the MTS func-
tion in the Audio menu.
2. Display item WBAN on screen.
3. Connect oscilloscope to pin 14 of H002.
4. Change data by VOLUME s/t buttons so
that 300Hz element on scope becomes mini-
mum.
5. Display item SPEC on screen.
6. Change data by VOLUME s/t buttons so
that 3kHz element on scope becomes mini-
mum.