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Philips N4307 Manual page 8

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level indicator may be adjusted with R446 so that it registers on the division
between the red and black sectors of the scale. Remove the input signal and
switch to "'Record"'; the meter pointer should be deflected up to a maximum
of 1mm., due to bias current.
Correction Coil L2 (adjusted only on replacement): Depress the ''Record"'
key only and apply a 1 kHz signal to pin 3, Sktz, so that a voltage of 0-775 mV,
measured with an A.C. millivoltmeter, is present at MPx, with the track
selector switch S2 set to position "1-4". Change the input signal frequency to
14kHz. The voltage at MP1 should now read 3-5mV; adjust correction coil
L2 for this reading, then seal it with locking paint.
Cleaning: The magnetic heads, tape guides and capstan should be cleaned
at regular intervals if optimum performance is to be maintained.
Remove
cover for access to these parts, which can be cleaned with a soft cloth wrapped
around a wooden stick and moistened with methylated spirits or industrial
alcohol. Metal objects should not be allowed to come into contact with the
magnetic head faces.
Magnetic head faces; Tape guides; Capstan and pressure roller; Drive
belts; Grooves in flywheel and pulleys; All friction driven surfaces; Brake
shoes and braking surfaces of turntables. Clean the inside of both turntables
with a soft dry brush and if necessary clean or replace pressure felt.
D.C. Voltages—Switch to " Record".
Stage | Collector | Base | Emitter
Tr
1°35
0°62
T2
1°38
0-6
——
13
1°82
0°62
0°16
T4
5°3
1°18
0°65
Ts
7-6
0:8
0°65
T6
13'0
1°S7
I*44
T7
130
13'I
TS
24'S
13°3
13'2
Tro
10°8
orl
0°78
Switch to " Playback"'.
Stage | Collector | Base | Emitter
Tr
1°36
0°62
T2
1°33
0°59
T3
I'9
0°68
018
T'4
5°6
1°22
O'7
Ts
8-6
1'99
P37
T6
13°25
1'6
I°47
a7
13°25]
13°4
T8
2.5
13°6
13°5

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