Colour Difference Level; Pal Burst Position - JVC HR-S6700MS Service Manual

(4) Adjust the adjustment part (F2) so that the difference be-
tween the blanking level and the pedestal level of the R-
Y waveform becomes the specified value (G).
Blanking level
Specified value (G)
Pedestal level
R – Y signal
Fig. 3-5-2b

3.5.3 Colour difference level

Signal (A1) • Ext. input
(A2) • Color (colour) bar signal [SECAM]
Mode (B) • EE
Equipment (C) • Oscilloscope
Measuring point (D) • TP3504 round (CONV'D COLOR)
Adjustment part (F1) • L3513 (SECAM DECODE ADJ.)
(F2) • VR3502 (SECAM DECODE)
(F3) • VR3506 (B-Y LEVEL ADJ.)
(F4) • VR3505 (R-Y LEVEL ADJ.)
Specified value (G1) • Less than 30 mVp-p (CARRIER LEAK)
(G2) • 460 ± 20 mVp-p : VR3506 (B-Y)
(G3) • 620 ± 20 mVp-p : VR3505 (R-Y)
(1) Observe the C (converted colour) waveform at the meas-
uring point (D).
(2) Fine adjust the adjustment part (F1) so that the carrier
leak becomes the specified value (G1). In case the ad-
justment cannot be accomplished, after fine adjust the
adjustment part (F1) so that the carrier leak is reduced
to its minimum level then fine adjust the adjustment part
(F2).
(3) Adjust the adjustment part (F3) so that the higher level
of the Yellow and Blue of the C waveform becomes the
specified value (G2).
(4) Adjust the adjustment part (F4) so that the higher level
of the Green and Magenta of the C waveform becomes
the specified value (G3).
CARRIER
LEAK
Specified
value (G1)
YELLOW
Fig. 3-5-3a Colour difference level
3-6
H.rate
DEMOD Fo-2
GREEN
Specified
value (G3)
Specified
value (G2)
BLUE
MAGENTA

3.5.4 PAL burst position

Signal (A1) • Ext. input
(A2) • Color (colour) bar signal [SECAM]
Mode (B) • EE
Equipment (C) • Oscilloscope
Measuring point (D1) • CN3502 pin 1
(D2) • TP3504 (CONV'D COLOR)
Adjustment part (F) • VR3503 (PAL BURST ADJ.)
Specified value (G) • Tr = 5.6 ± 0.1 µsec
(1) Observe the waveforms appeared at the measuring
points (D1) and (D2).
(2) Adjust the adjustment part (F) so that the waveforms tim-
ing width between the H-SYNC and the colour burst sig-
nal becomes the specified value (G).
Colour burst signal
C
(Converted colour)
Y
H-SYNC
Specified value (G)
Fig. 3-5-4a PAL burst position