Slow Tracking Preset; Video Circuit; Ee Y/Pb Y(S-Vhs/Vhs)Level; Audio Circuit - JVC HR-S6950EU Service Manual

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3.3.1.2Slow tracking preset

Signal
Mode
Measuring point (D)
Adjustment part
Specified value
Adjustment tool
(1) Record the signal (A2) in the mode (B1), and play back
the recorded signal.
(2) Set the VCR to the manual tracking mode.
(3) Set the VCR to the FWD slow (+1/6x) mode.
(4) Transmit the code (F) from the Jig RCU to adjust so that
the noise bar becomes the specified value (G) on the TV
monitor in the slow mode.
(5) Set the VCR to the Stop mode.
(6) Confirm that the noise bar is (G) on the TV monitor in
the slow mode.
(7) Repeat steps (3) to (6) in the REV slow (–1/6x) mode.
(8) Repeat steps (1) to (7) in the mode (B2).
Note:
• For FWD slow (+1/6x) playback, transmit the code "08"
from the Jig RCU to enter the slow playback mode, and
transmit the code "D0" for REV slow (–1/6x) mode.

3.3.2 Video circuit

3.3.2.1 EE Y/PB Y (S-VHS/VHS) level
Signal
Mode
Equipment
Measuring point (D)
EVR mode
EVR address
Specified value
Adjustment tool
(1) Input the signal (A3) from the input point (A1).
(2) Set the VCR to the mode (B1).
(3) Observe the Y OUT waveform at the measuring point (D).
(4) Set the VCR to the EVR mode by transmitting the code
(F1) from the Jig RCU.
(5) Set the EVR address to (F2) by transmitting the code (F3)
from the Jig RCU.
(6) Transmit the code (F4) from the Jig RCU to adjust so that
the Y level of the Y OUT waveform becomes the speci-
fied value (G).
(7) Release the EVR mode of the VCR by transmitting the
code (F1) from the Jig RCU again. (When the EVR mode
is released, the adjusted data is memorized.)
(8) Input the signal (A3) from the input point (A2).
(9) Repeat steps (3) to (7) in the mode (B1).
(A1) • Ext. input
(A2) • Color (colour) bar signal [PAL]
(B1) • VHS SP
(B2) • VHS LP
• TV-Monitor
(F) • Jig RCU: Code "71" or "72"
(G) • minimum noise
(H) • Jig RCU [PTU94023B]
•
(A1) Ext. S-input
•
(A2) Ext. input
•
(A3) Color (colour) bar signal [PAL]
•
(B1) EE SP
•
(B2) S-VHS SP
•
(B3) VHS SP
•
(C) Oscilloscope
•
Y OUT terminal (75Ø terminated)
•
(F1) Jig code "57"
•
(F2) A : 11
•
(F3) Jig code "21" twice
•
(F4) Jig code "18" or "19" (Channel +/-)
•
(G) 1.00 ± 0.05 Vp-p
•
(H) Jig RCU [PTU94023B]
Digitized in Heiloo Netherland
(10) Record the signal (A3) in the mode (B2), and play back
the recorded signal.
(11) Set the VCR to the manual tracking mode.
(12) Repeat steps (3) to (7) in the mode (B2).
(13) Record the signal (A3) in the mode (B3), and play back
the recorded signal.
(14) Set the VCR to the manual tracking mode.
(15) Repeat steps (3) to (7) in the mode (B3).
H. rate
Fig. 3-3-2-1a

3.3.3 Audio circuit

Notes:
• GND (Ground) should be taken from the Tuner shield
case.

3.3.3.1 Audio REC FM

•
Signal (A1) Ext. input
•
(A2) Audio: No signal
•
(A3) Video: Color (colour) bar signal [PAL]
•
Mode (B) S-VHS LP
•
Equipment (C) Oscilloscope
•
Measuring point (D) TP2253 (A. PB. FM)
•
External trigger (E) TP111 (D.FF)
•
Adjustment part (F) VR2251
•
Specified value (G1) 600 ± 100 mVp-p
•
(G2) More than 400 mVp-p
(1) Apply the external trigger signal to D.FF (E) to observe
the Audio PB FM waveform at the measuring point (D).
(2) Record the signal (A3) with no audio signal input in the
mode (B), and play back the recorded signal.
(3) Set the VCR to the manual tracking mode.
(4) If the A.PB FM level is not within the specified value (G1),
perform the adjustment in a following procedure.
(5) Adjust the Adjustment part (F) so that the A. PB FM level
of the higher channel level becomes the specified value
(G1). (Adjust before recording, then confirm it by playing
back.)
(6) If the specified value (G1) is not obtained, adjust the Ad-
justment part (F) so that the waveform level of the lower
channel level becomes the specified value (G2). (Adjust
before recording, then confirm it by playing back.)
Specified
value (G2)
V. rate
Fig. 3-3-3-1a
3/28/2017
Y level
EE/PB Y level
Specified
value (G1)
Audio REC FM
3-5