Level Adjustment; Meter Adjustment - Panasonic RS-736US Service Manual

RECORDING LEVEL ADJUSTMENT & VU METER ADJUSTMENT
Recording Playback
Amplifier Amplifier
Fig. 25
Instruments required: Oscillator, attenuator, VTVM VU meter adjustment:
Recording level adjustment: 1. In this condition, set the tape/source selector switch
recording mode, and make a recording by supplying meter deflects around 0 VU.
a —20 cB (1 kHz) to the Aux-2 input terminal. Recording monitor level adjustment:
2. Set the tape/source selector switch to TAPE, and 1. Jn the same condition as above, move the selector
adjust VRQ (CH-1) and VR10 (CH-2) until the output switch to SOURCE and adjust VR11 and VR12 until
of Line Out-1 becomes 1.0 V. the output of Line Out-1 becomes 1 V.
OVERALL FREQUENCY RESPONSE ADJUSTMENT (1)
Instruments required: Oscillator, attenuator, VTVM (see 3-3/4 ips 60HZ~7.5 kHz ...... Deviation 3 dB
Fig. 25) 30 Hz~ 12 kHz...... Deviation 5 dB
15 ips 100 Hz~ 10 kHz ...... Deviation 3dB
30 Hz~ 30 kHz ...... Deviation 10 dB
For 3-3/4 ips tape speed:
For 7-1/2 ips tape speed:
1. Supply an input signal of —35 dB to Aux-2, and, after
recording and playback, re-adjust the bias current
until the 10 kHz output becomes the same level as Record 30Hz~12 kHz at a —35 dB level to Aux-2 in
the output of Line Out-1 at 1 kHz. (Adjustment the same way as for the 7-1/2 ips tape speed adjust-
points: VR31, VR32) ment, and adjust VR13 and VR14 until the frequency
response during playback conforms to the standard.
For 15 ips tape speed:
Record 30 Hz~30 kHz, and adjust L3 and L4 Gntil the
frequency response during playback conforms to the
2. Record 30 Hz ~ 25 kHz signals, and adjust the pea-
king coils, L1 and L2, until the frequency response
during playback conforms to the standard.
STANDARD standard.
7-1/2 ips 200 Hz~ 10 kHz ...... Deviation 3 dB For frequency response about 30 kHz, adjust VR15 and
30 Hz~ 23 kt ...... Deviation 9 dB VR16.
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RECORDING LEVEL RE-ADJUSTMENT
When the bias current is adjusted during the overall frequency response adjustment, re-adjust the recording level.
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A