Sony XR-4803 Section Mechanical Adjustments, Section Electrical Adjustments, Torque Measurement

SECTION 4

MECHANICAL ADJUSTMENTS

1. Clean the following parts with a denatured-alcohol-moistened

swab:
playback head	pinch roller
rubber belt	capstan
idler

2.Demagnetize the playback head with a head demagnetizer.

3.Do not use a magnetized screwdriver for the adjustments.

4.After the adjustments, apply suitable locking compound to the parts adjusted.

5.The adjustments should be performed with the power supply voltage unless otherwise noted.

• Torque Measurement

Mode	Torque Meter	Meter Reading
Forward	CQ-102C	30 – 65 g•cm
		(0.42 – 0.90 oz•inch)
Forward	CQ-102C	0.5 – 4.5 g•cm
Back Tension		(0.01 – 0.06 oz•inch)
Reverse	CQ-102RC	30 – 65 g•cm
		(0.42 – 0.90 oz•inch)
Reverse	CQ-102RC	0.5 – 4.5 g•cm
Back Tension		(0.01 – 0.06 oz•inch)
FF, REW	CQ-201B	60 – 200 g•cm
		(0.83 – 2.78 oz•inch)

• Tape Tension Measurement

Mode	Tension Meter	Meter Reading
Forward	CQ-403A	more than 90 g
		(more than 3.18 oz)
Reverse	CQ-403R	more than 90 g
		(more than 3.18 oz)

SECTION 5

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.Set the “power select” switch (S501) is “A” position.

2.Turn ON the regulated power supply. (All LEDs on the set lights up, and the clock is displayed.)

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

3.Push the preset [4] button.

4.Push the preset [5] button.

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

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

<Release the Test mode>

1.Push the [OFF] button.

2.Return the “power select” switch (S501) to initially set posi- tion.

See the adjustment location from on page 16 for the adjustment.

TAPE DECK SECTION 0 dB=0.775 V

Tape Speed Adjustment

Setting:

		speed checker
		or
test tape		frequency counter
WS-48A
(3 kHz, 0 dB)	4	Ω
set		– +

speaker out terminal

Procedure:

1.Put the set into the FWD PB mode.

2.Adjust adjustment resistor for inside capstan motor so that the reading on the speed checker or frequency counter becomes in specification.

Specification: Constant speed

Speed checker	Frequency counter
–1.5 to +2.5%	2,955 to 3,075 Hz
Adjustment Location: See page 16.

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