1-14 (No.MB159)
SECTION 4
ADJUSTMENT
4.1 Tuner section
4.1.1 Tuner range
4.2 Power amplifier section
4.2.1 Adjustment of idling current
Measurement location : TP301
(Lch) , TP302 (Rch)
Adjustment part : VR301
(Lch) , VR302 (Rch)
Attention :
This adjustment does not obtain a correct adjustment value immediately after the amplifier is used (state that an internal temperature
has risen).
Please adjust immediately after using the amplifier after turning off the power supply of the amplifier and falling an internal
temperature.
Adjustment method
(1) Set the volume control to minimum during this adjustment. (No signal & No load)
(2) Set the surround mode OFF.
(3) Turn VR301
and VR302 fully counterclockwise to warm up before adjustment.
If the heat sink is already warm from previous use the correct adjustment can not be made.
(4) For L-ch, connect a DC voltmeter between TP301
's B216 and B217 (Lch) and, connect it between TP302's B218 and B219
(Rch).
(5) Adjust the VR301 (Lch) and VR302 (Rch) so that the DC voltmeter indicates 2.0mV immediately after turning the power on.
• It is not abnormal though the idling current might not become 0mA even if it is finished to turn variable resistance (VR301
, VR302)
in the direction of counterclockwise.
FM : 87.5 MHz to 108.0 MHz
AM : 530 kHz to 1710 kHz
Front amp. board (L)
CN302
VR302
Front amp. board (R)
TP302
CN301
VR301
TP301
VR301 (Lch)
TP301 (Lch)
VR302 (Rch)
TP302 (Rch)
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