Syscon Circuit - JVC HR-S2110T Service Manual

3.5.8 Sub DET [HR-S6700KR]
Signal (A) • RF signal (sound carrier: S2)
Mode (B) • Tuner
• EE
Equipment (C) • Audio level meter
Measuring point (D) • IC1501 pin 26
Adjustment part (F) • T1501 (SUB DET)
Specified value (G) • Minimum distortion
Adjustment tool (H) • LPF (30 kHz), HPF (400 Hz)
(1) Set the sound carrier of the RF signal generator to S2.
(2) Connect the adjustment tool (H) to the measuring point
(D). Then connect the equipment (C) to the adjustment
tool (H).
(3) Adjust the Adjustment part (F) so that the distortion level
of the measuring point (D) becomes the specified value
(G).
3.5.9 Pilot VCO [HR-S6700KR]
Signal (A) • No signal
Mode (B) • Tuner
• EE
Equipment (C) • Frequency counter
Measuring point (D1) • IC1501 pin 11
Short point (D2) • C1510 (+) terminal
(D3) • C1510 (–) terminal
Adjustment part (F) • VR1502 (PILOT VCO)
Specified value (G) • 210 ± 5 Hz
(1) Connect the short wire between the short points (D2)
and (D3).
(2) Connect the equipment (C) to the measuring point (D1).
(3) Adjust the Adjustment part (F) so that the frequency of
the measuring point (D1) becomes the specified value (G).
(4) Disconnect the short wire between the short points (D2)
and (D3).
3.5.10 Separation [HR-S6700KR]
Signal (A) • Sweep generator output (90 dB, 1 kHz)
Mode (B) • EE
Equipment (C) • Oscilloscope
Measuring point (D) • IC1501 pin 19
Adjustment part (F) • VR1501 (SEPARATION)
Specified value (G) • Minimum level
Adjustment tool (H) • Sweeper probe (See Fig. 3-5-10a.)
R : 75Ω
Shield
Fig. 3-5-10a
(1) Use the adjustment tool (H), supply 1 kHz R-only modu-
lated IF signal to IF terminal of U/V tuner (front end).
(2) Connect the equipment (C) to the measuring point (D).
(3) Adjust the Adjustment part (F) so that the output level
of the measuring point (D) becomes the specified value
(G).
Shorter than 8 cm
C : 1000 P
Out
Earth
Shorter than 5 cm
Sweeper probe

3.6 SYSCON CIRCUIT

Note:
• When perform this adjustment, remove the Mechanism
assembly.
3.6.1 Timer clock
Signal (A) • No signal
Mode (B) • EE
Equipment (C) • Frequency counter
Measuring point (D1) • IC3001 pin61
Short point (D2) • IC3001 pin24
(D3) • C3026 + and –
Adjustment part (F) • C3025 (TIMER CLOCK)
Specified value (G) • 1024.008 ± 0.001 Hz
(976.5549 ± 0.0010 µsec)
(1) Connect the frequency counter to the measuring point
(D1).
(2) Connect the short wire between the short point (D2) and
Vcc (5V).
(3) Short the leads of capacitor (D3) once in order to reset
the microprocessor of the SYSCON.
(4) Disconnect the short wire between the short point (D2)
and Vcc then connect it again.
(5) Adjust the Adjustment part (F) so that the output fre-
quency becomes the specified value (G).
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