Sony MDX-C5970R service manual MD Section, Tuner Section, FM Auto Scan/Stop Level Adjustment

SECTION 3

ELECTRICAL ADJUSTMENTS

TEST MODE

This set have the test mode function. In the test mode, FM Auto Scan/Stop Level and AM (MW) Auto Scan/Stop Level adjustments can be performed easier than it in ordinary procedure.

<Set the Test Mode>

1.Turn ON the regulated power supply. (The clock is displayed)

Note: Press the [OFF] button, if the clock is not displayed.

2.Push the preset [4] button.

3.Push the preset [5] button.

4.Press the preset [1] button for more than two seconds.

5.Then the display indicates all lights, the test mode is set.

<Release the Test mode>

1. Push the [OFF] button.

See the adjustment location from on page 18 for the ad- justment.

MD SECTION

MD section adjustments are done automatically in this set.

TUNER SECTION 0 dB=1 µV

Cautions during repair

When the tuner unit is defective, replace it by a new one be- cause its internal block is difficult to repair.

Note:

Adjust the tuner section in the sequence shown below.

1.FM Auto Scan/Stop Level Adjustment.

2.FM Stereo Separation Adjustmnet.

3.AM (MW) Auto Scan/Stop Level Adjustment.

4.RDS S-Meter Adjustment. (MDX-C5960R/5970R)

FM Auto Scan/Stop Level Adjustment

Setting:

[SOURCE] button: FM

FREQUENCY SELECT switch: FM 200 k (E model)

FM RF signal
	generator			antenna jack (J1)
			0.01 ∝F
					set
Carrier frequency: 97.9 MHz (MDX-C5970)
		98.0 MHz (MDX-C5960R/C5970R)
Output level		: 22 dB (12.6 ∝V)
Mode		: mono
Modulation		: 1 kHz, 22.5 kHz deviation (30%)

Procedure:

1.Set to the test mode.

2.Push the [SOURCE] button and set to FM.

Display

SHUF

*1

3.Adjust with the volume RV2 on TU1 so that the “FM” indica- tion turns to “FM0” indication on the display window.

But, in case of already indicated “FM0”, turn the RV2 so that put out light “0” indication and adjustment.

Display

SHUF

*1

*1: MDX-C5960R/C5970R indicate “98.00”.

Adjustment Location: See page 18.

FM Stereo Separation Adjustment

Setting:

[SOURCE] button: FM

FREQUENCY SELECT switch: FM 200 k (E model)

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

LINE OUT jack (CNP300)

		MDX-C5970	MDX-C5960R/
			C5970R
Carrier frequency		97.9 MHz	98.0 MHz
Output level		60 dB (1 mV)	70 dB (3.2 mV)
Mode		stereo	stereo
	main	1 kHz, 33.75 kHz	1 kHz, 16.25 kHz
		deviation (45%)	deviation (21.7%)
Modulation	sub	1 kHz, 33.75 kHz	1 kHz, 16.25 kHz
		deviation (45%)	deviation (21.7%)
	19 kHz	7.5 kHz	7.5 kHz
	pilot	deviation (10%)	deviation (10%)

Procedure:

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.

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 18.

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