Tandberg 62-X Service manual

January 1967

TANDBERG

Models 64x

The models 64x the earlier models

tion is

64:-62. electrical adjustments necessary for 62x.

The models

facilities

an appendix to

lt

as 64-62. A new,

and

64-62

covers the special

64x and

are improved versions

62x

and this

the

62x

service

have the

alignment instruc-

manual

head alignments

and

separate

TAPE.RECORDER

Alignment

heads

and

Preface

for

model

same operation

64x

bias head

instruction

for

electronics

of has been introduced

and torized. Certain minor and

and 62x

to improve the frequency

the

is

operated

ratio.

fully transis-

and

introduced

further introduced

is

1.7/e i.

in

bias

automatically

sponse and the signal The

oscillator has

in the equalization circuits, mainly changes ponent

in tape speed. This switch the

bias

the

speed

values. A

circuit

selector

to noise

been redesigned

changes have been

microswitch

to

reduce

mechanism. See fig. 3.

re-

of com-

p.s.

by

TANDBERGS

Ti.^d.{*..q

r=r=rErlEr/

RADIOFABRIKK

A/S

OSLO

NORWAY

1.0 Alignment It

is important that

the

heads

this

recorder

tape

sponse and

1.0.1 Demagnetizing Demagnetize aligning

on

contact the

5-10 times at normal speed

polished

the signal

the heads.

the

the tape

tape should be run through the

before measuring

the heads and adjacent

contact

recorder is

to noise

between

good.

the

ratio.

the

tape and

To

obtain

to have the

frequency

parts

before

tape

re-

tape speed. corresponding the height of the is

botained on a

Azimuth alignment:

3.1.3 Play back the test tape No. pre-recorded speed. head until maximum reading

output

meters.

The record level of the

to track 3 is

playback

V.T.V.M. from

tape with 10.000

Adjust the

azimuth

head

position

area

exact

reduced

track

2. This is a full track cls al 71lz i.p.s. tape

is obtained on both

30 dB.

minimum output

until

(ch.

3

of

2).

the

Adjust

playback

1.0.2. The mounling The

height of the mounting

is

aligned by the adjustment screw

playback

normal forward

the the guide

1.0.3

Set the tape

the

equidistant

guide.

2.O Adjustment of

circuits.

2.0.1 Insert bias head half to

across each

2.O.2

tion while R607 and R610 are o'clock. Rel. fig.

2.0.3 Set the

2.0.4 Use a meter or adjust the oscillator

=

2.0.5 Set the and

2.0.6

F/osc.

2.0.7

2.0.8 Readjust L osc.

CH 1, CH 2 and stereo

The deviation should be indicated

meter, long wave

2.0.9

V.T.V.M.

3.0 Test Tapes,

3.1.

3.1.1 Connect

FOLLOWER

3.1.2 Height

Play back

pre-recorded

head. Move

height of

runs

tape

(79,2).

The adjustable tape

operating lever in

inserted

adjustable tape

from the

Repeat

one

resistor.

R 609 and R 612 is turned up

the

speed selector

calibrated

frequency

kc/s.

85.5

the

speed selector to 7tlz

Adjust

will

then

the

Set

frequency

Adjust

Head

C 602

(between

alignment

Model

playback

The

output.

alignment:

the test tape

plate

lor the heads

plate

for the

the operating lever

with

drive

mounting

the

equidistant

and depress the

guide

1.0.2.

10 ohm resistor

ground

3. recorder

tape

to

tape recorder

the oscillator

be

85.5 kc/s.

recorder for mono recording CH 2.

tape

to

601 deviation between mono recording

receiver or

and

100 mV and 400 mV).

64x

head

one

tape with

tight

a

from the

guide

flanges

the

7tlu i.p.s.

long wave

counter for the indication

frequency

compromise

should

604

and track

V.T.V.M.

1000

tape

plate

for the heads

flanges of the tape

normal forward

push-button

(79.3)

until

of

the adjustable tape

oscillator and bias head

in series with each

and

connect

set

to stereo recording and

receiver, frequency

by

for mono recording

i.p,s.

frequency with

be less

frequency

to max. reading on the

control

to each

No. 1.

This is

c/s recorded

(15.4)

heads

rear

at the

inserted.

the

a V.T.V.M.

1 o'clock

to

to approx. 11

C 610 until f/osc.

if necessary. The

than 2 kc/s.

with

counter.

with

a full track

atTt/zi.p.s.

the

of

slowly

Align

until

with

drive

lll. Align

runs

tape

posi-

and

CH

L601

frequency

Tandberg

CATHODE

Lateral

3.1.4. Check

pulling head when

to

output level Adjust the necessary, adjust the

The

3.2 Adjust

3.2.1

the

until

fig. 1.

Adjust

3.2.2 runs freely

Height

3.2.3

record

The approx.

upper track is visible

the record

powder on the

pattern head is

Azimuth

3.2.4

Connect

CH1 and

FOLLOWER

1

Make a

15.000 c/s head to put

level playback gain

controls until this is obtained and

azimuth

Lateral

3.2.5

Check the pulling

head during the recording. not

decrease

position the head mounting azimuth

3.2.4. The

3.3 Heighl

3.3.1

Connect heads.

i.p.s.

71 lz down

alignment:

the

lateral pressure pad

the

the test

should not decrease more lateral by turning the head mounting

azimuth

record

head is in

0.1 mm

method tape on the tape will correct.

a signal

stereo max. reading

volume controls

position

the

of the record head, if necessary, by turning

position

Set

to

0.

head.

the horizontal

the height

in the

alignment:

head is

head can

(Magna-See).

and dip the tape in the solution. The

Readjust

alignment:

and

CH2,

outputs

recording in

signal.

should now be approx. 100 mV with the

alignment:

lateral

pressure pad

more

head.

bias

alignment:

V.T.V.M.

two

the tape recorder to

and turn both

position

position.

groove

set

(.0025")

generator

Adjust

of the record head.

position

of

(59.5)

No.

tape

of

position

center of the record head. Ref.

the

of

in front

preliminary position

in a

of

above the tape. The

inspected

be

show il the

if necessary.

V.T.V.M.

two

and

CH1

the azimuth of the record

the

on

to max.,

(59.5)

than 3

plate.

the head. Ref.

directly across the

playback

the

from

away

played

2 is

playback

the

of the bias

bias head until

of the

lamination for the

the

by using the iron

Record all

to the HI-LEVEL inputs

to

CH2.

B-test al 7t/z i.p.s. of

readjust

away

Adjust the

dB.

stereo

meters.

record head

para.

volume controls

output

of the

The output level should

Recheck the height and

head by

the erase

back.

than 3 dB.

head, is

plate.

the

bias

head.

position

four tracks

position

the

CATHODE

The out-

the record check

from

the erase

3.2.3 and

recording

recording at

The

Re-

head

tape

where

of

of the

a

the

by

lateral

Adjust the height of adjustment screw obtained freely in the that head and The height and mounting raise

3.3.2 Connect two V.T.V.M. outputs, and

LEVEL inputs to back volume controls Record Untighten the

(ref.

Ieft

reading should now controls until this is tal that the tighten the

the head is

indicated A fine-adjustment the

R

609 and R

meters

3.4 The

3.4.1

The erase head is

approx.

upper track

tape. Insert

signal from the

cording level. Dip

and

of

does

3.4.2 Azimuth

Align the

azimuth adjustment

parallel

The

3.4.3 Lateral

Turn the

the front

3.5 Model All

and paragraph paragraph

4.0 with

4.1 Play recorded

on

both

groove

is

there

if

the clearance between

the bias head slightly.

Horizontal

stereo recording al 71lz i.p.s.

fig.

position

pot.meters

Height adjustment:

check that the re-recorded

the

not

azimuth

the

3'4 are valid for

control

Tandberg

Control of

back the test

sufficient

the

mounting

position

plate

alignment:

connect a signal

CHI and CH2.

a 1000

is

are obtained.

erased track. Make

with the

alignments

c/s

fixing

'1)

move the

and

towards

obtained

be approx..5V,

the

of

horizontal

adjustment

not being moved.

by a loss

R609

612 until max. reading

erase head.

0.25 mm of

the test tape No.

erase any

alignment:

azimuth

position alignmenl:

head mounting

the

of

62x.

3.1.2 which

3.2.3 is and adiustment

test tapes.

tape with the

the

(ref.

fig.

V.T.V.M.

in front

clearance between the bias

plate

the

of

for the record

to both

to max.

signal.

screw

bias head from the

the recording head

on both

obtained and check

bias head. After

position

of the output level.

the

of

bias current is

(CH1)

in

set

a

(.01")

of

the

erase head is visible

generator

tape in

the

part

of

position

screw. The

mounting

of the erase head is not

plate

head is

the

parallel

specified

model 62x with

is

superseeded by 6.6.2.

playback

tape No.

following frequencies:250-

bias head

1) until max. reading is

Check

of

for

bias head is not

the bias head and the

CATHODE

Set

for

horizontal adjustment

V.T.V.M. The output level

readjust

is

screw making

and

preliminary position

the

9 and

on

ch. 2 at maximum re-

the Magna-See

sure that the

the adjacent tracks.

of the

erase head

plate

for the

in chapters

superseeded by 6.1.1

ol

amplifier:

This

3.

by the

that

the

bias head and

the record head.

head is

generator

the

tape recorder

turn

and

the record

one has assured

correctly

This is eventually

(CH2).

R612

on

ferrite core for the

record

track lies

erase head by the

for the

erase head, until

pressure pad.

to the

the exception-o1

playback

is

a full track

height

tape

critical,

insufficient,

FOLLOWER

to the Hlboth

extreme

until

the

horizon-

adjusted,

sure that

obtained by

Adjust

the optput

where

above the a 1000

solution

in

center

erase head

should

heads

(15.4).

critical.

3.1, 3.2, 3.3,

amplifiers,

runs

play-

max.

gain

c/s

be

and

pre-

10

000- 5000 - 1C00 - 100i.p.s. tape standards. The frequencies. channels

4.2 Play controls tape potentiometers reading

5.0 Adjustment of the Make and 3.0 are made before

justments. Connect a

and two V.T.V.M. puts.

Record playback the record levels the output lV and V by

R115

the output meters

on Adjust tronic buttons lV

readings

6.0 Head alignment

6.1 The

6.1.1 Height The height adjustment

shall

channel

6.1.2 Azimuth Play

V.T.V.M.

Adjust the azimuth obtained on the output

6.1.3 Lateral Pull when played

more playback

mounting

6.2

iorro*'in"l

6.3

Follow

6.4 The erase

6.4.1 Height The adjustment

speed. The tape

output tolerance is

The

difference in

should be less than 3 dB.

Adjustment

the test

back

to maximum. This is

with 400 c/s

R233

on the

electronic

sure

a 4O0

R 137

beam indicators

height

run flush with

back a standard

the

back. The

than 3 dB. Adjust

The

the instructions

height

output meters

beam indicators.

that

all adjustments

signai

cls signal in

volume

levels

(stereo

1.

connected to

adjustment

pressure

B-test) and

(CHl)

and

(CHl)

and V

still are 1.5 V on

playback

alignnnent:

of the

alignmenl:

position

alignment:

standard azimuth alignment

head, if plate.

record

instructions

bias head.

head.

alignment:

of the erase

screws. Approx.0.25

playback

of the

tape No. 4 with

at71/z i.p.s. tape speed.

(CH

the record

generator

to both

controls to max. at 7tlz i.p.s. Adjust

by the record

1.5 V. Depress

are

R116 are 1.5 V.

and R 138

are

(stereo

without Tandberg

head.

playback

screws. The upper edge

the

azimuth

each cathode follower

of

screw,

meters.

pad

(59.5)

output

necessary,

bead.

given

head is

50-250 c/s

conforms

a full track

1)

and

are 1.3V.

proceeding

to

CATHODE

stereo A-test, with both

adjust (CH2)

closing. A-test) the output

head is

upper

playback

the

until

away from the

level

lateral

the

under

recorded

with the N.A.B.

-+

2

dB

level

between the

amplifiers:

the output

prerecorded

Ad.just the

(CH

R234

current

under

both Hl-LEVEL

gain

the until the readings

(CH2)

Release the

and

part

alignment tape with a

maximum

should not

by turning

aligned by

2)

(A-B

paras

with these ad-

FOLLOWER

controls

push-buttons

the

record current

until the elec-

check

meters.

Test Tapes.

aligned by the

of

of the airgap

head by the

reading is

erase head

tape is

position

para3.z.

para

3'3'

the height

(.01

mm

at71/t

for

all

two

volume

the

until

test) and

1.0,

2.0

inputs

out-

until

push-

that the

the tape

for

output.

being

decrease

the

of

the head

")

of the