Demodulator Circuit - JVC HR-S2110T Service Manual

(8) If the specified value (G1) is not obtained, adjust with the
channel buttons (+, –) so that the waveform level of the
lower channel level becomes the specified value (G2).
(Adjust before recording, then confirm it by playing back.)
(9) 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.)
Specified
value (G2)
V. rate
Fig. 3-4-1a
3.5

DEMODULATOR CIRCUIT

Notes:
• Unless otherwise specified in this demod circuit adjust-
ments, all measuring points and adjustment parts are
located on the Demod board.
• Unless otherwise specified,set an audio multiplex TV
signal generator as follows;
[HR-S2110T, S7800U/U(C)]
RF signal : 70 dBµ / 75 Ø , color bar 87.5% modulation.
[HR-S6700KR]
RF signal : 70 dBµ / 75 Ø , color bar 87.5% modulation.
(P/S1 = 13 dB, P/S2 = 20 dB)
3.5.1 Input level [HR-S2110T, S7800U/U(C)]
Signal (A) • RF signal (Audio: mono 300 Hz)
Mode (B) • Tuner
• EE
Equipment (C) • Audio level meter
Measuring point (D) • IC1501 pin 26
EVR mode (F1) • Jig RCU : Code "57"
EVR address (F2) • A : 20 (Press remote controller "2"
and "0" keys.)
Specified value (G) • 500 ± 10 mVrms
Adjustment tool (H) • Jig RCU [PTU94023B]
• Digit-key remote controller
(1) Set an audio signal mode of the RF signal generator to
mono 300 Hz.
(2) Connect the equipment (C) to the measuring point (D).
(3) Set the VCR to the EVR mode by transmitting the code
(F1) from the Jig RCU.
(4) Set the EVR address to (F2) by pressing the button of
the digit-key remote controller.
(5) Adjust with the channel buttons (+,–) on the VCR (or on
the remote controller) so that the level of the measuring
point (D) becomes the specified value (G).
(6) 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.)
Specified
value (G1)
Audio REC FM
3.5.2 Stereo VCO [HR-S2100T, S7800U/U(C)]
Signal (A) • No signal
Mode (B) • Tuner
• EE
Equipment (C) • Frequency counter
Measuring point (D1) • IC1501 pin 26
Short point (D2) • C1505(–) terminal
EVR mode (F1) • Jig RCU : Code "57"
EVR address (F2) • A : 21 (Press remote controller "2"
and "1" keys.)
Specified value (G) • 15.73 ± 0.1 kHz
Adjustment tool (H) • Jig RCU [PTU94023B]
• Digit-key remote controller
(1) Connect the short wire between the short point (D2) and
the GND (Ground).
(2) Connect the equipment (C) to the measuring point (D1).
(3) Set the VCR to the EVR mode by transmitting the code
(F1) from the Jig RCU.
(4) Set the EVR address to (F2) by pressing the button of
the digit-key remote controller.
(5) Adjust with the channel buttons (+,–) on the VCR (or on
the remote controller) so that the frequency of the meas-
uring point (D1) becomes the specified value (G).
(6) 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.)
(7) Disconnect the short wire between the short point (D2)
and the GND (Ground).
3.5.3 Stereo filter [HR-S2110T, S7800U/U(C)]
Signal (A) • RF signal (Audio: No signal)
Mode (B) • Tuner
• EE
Equipment (C) • Oscilloscope
Measuring point (D) • IC1501 pin 26
EVR mode (F1) • Jig RCU : Code "57"
EVR address (F2) • A : 22 (Press remote controller "2"
key twice.)
Specified value (G) • Minimum level
Adjustment tool (H) • Jig RCU [PTU94023B]
• Digit-key remote controller
(1) Set an audio signal mode of the RF signal generator to
no signal.
(2) Connect the equipment (C) to the measuring point (D).
(3) Set the VCR to the EVR mode by transmitting the code
(F1) from the Jig RCU.
(4) Set the EVR address to (F2) by pressing the button of
the digit-key remote controller.
(5) Adjust with the channel buttons (+,–) on the VCR (or on
the remote controller) so that the level of the measuring
point (D) becomes the specified value (G).
(6) 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.)
3-5