Sony XR-C440 service manual FM Noise Focus Adjustment, AM MW Auto Scan/Stop Level Adjustment

FM Noise Focus Adjustment

Setting:

SOURCE button : FM

FREQUENCY SELECT switch : 10 k

AM (MW) Auto Scan/Stop Level Adjustment

Setting:

SOURCE and MODE button : MW

FREQUENCY SELECT switch : 10 k

FM RF signal	antenna jack (J1)	level meter
generator
	0.01 ∝ F	10 k Ω
	set	+
		–

Carrier frequency	: 97.9 MHz	LINE OUT
Output level	: 60 dB (1 mV)
Mode	: mono
Modulation	: 1 kHz, 75 kHz deviation

Procedure :

1.Tune the 97.9 MHz

2.The then output level is supposing that (A) dB.

3.Adjust with the volume RV3 on TU1 so that the output level is

(A) –32 dB then signal generator input set to –20 dB.

Adjustment Location: See page 22.

AM RF signal

generator

AM dummy antenna (50 Ω )

Carrier frequency	: 1000 kHz
30% amplitude
modulation by
400 Hz signal	: 33 dB (44.7 ∝ V)
Output level

30 Ω	15 pF
	65 pF

set

antenna jack (J1)

FM Stereo Separation Adjustment

Setting:

SOURCE button : FM

FREQUENCY SELECT switch : 10 k

FM RF signal	antenna jack (J1)	level meter
generator
	0.01 ∝ F	10 k Ω
	set	+
		–

Carrier frequency	: 97.9 MHz			LINE OUT
Output level	: 70 dB (3.2 mV)
Mode	: stereo
Modulation	: main: 1 kHz, 20 kHz deviation (26%)
		sub: 1 kHz, 20 kHz deviation (26%)
		19 kHz pilot: 7.5 kHz deviation (10%)
FM Stereo			Level meter		Level meter
signal generator
			connection		reading (dB)
output channel
L-CH			L-CH		A
					B
R-CH			L-CH		Adjust RV4 on TU1
					for minimum reading.
R-CH			R-CH		C
					D
L-CH			R-CH		Adjust RV4 on TU1
					for minimum reading.

Procedure:

L-CH Stereo separation: A-B

R-CH Stereo separation: C-D

The separations of both channels should be equal.

Specification: Separation more than 30 dB

Adjustment Location: See page 22.

Procedure:

1.Set to the test mode. (See page 19.)

2.Push the SOURCE button and set to FM.

3.Push the MODE button and set to MW.

Display

MW	1
		SHUF1

4.Push the preset 3 button.

Display

MW 3 1 SHUF1

5.Adjust with the volume RV1 on TU1 so that the “MW” indica- tion turns to “MW0” indication on the display window.

But, in case of already indicated “MW0”, turn the RV1 so that put out light “0” indication and adjustment.

Display

3 1 SHUF1

Adjustment Location: See page 22.

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