TANDBERG 3000 X series User manual

TANDBERG
Series SOOOX
SERVICE MANUAL
;
ir--I
t ";' ll "--: I
TANDAERG
oc
reCOAO LEEL
ryr;
A
*q r
ruc
"t
-
;TANDBERGS RADIOFABRIKK A/S

-
-
A
^a

.G.
Contents
F
1.0TECHNICALSPECIFICATIONS
2.0 MECHANCIALADJUSTMENTS
2.1Clutches .....:.
2.1.1Take-up
Turntable
2.1.2 Take-up Turntable
2.1.3Supply
Turntable
2.1.4Supply
Turntable
2.2 Brakes
2.3 Pressure Pad Adiustment . .
2.4 End Stop Mechanism .
2.4.1Tape FeelerTension
2.4.2Adjustmentof Tape Feeler
3.0ALIGNMENT .
3.1 Demagnetlzing
3.2 Blas- and Erase Circuits
3.2.1
Oscillator Frequency ...
3.2.2 Erase Voltage
3.2.3Bias Current
4.0 TAPE PATH
4.1 Visual Check
4.2 Mechanlcal adjustment ol tape path . . .
5.0 HEADALIGNMENTWITH TANDBERGTEST
TAPES,MODEL3041X
5.1 Playback head
5.1.1HeightAdjustment
5.1.2Azimuth Adjustment
5.2 Record Head .
5.2.1HeightAdlustmentby Visual
Inspection
5.2.2Height Adjustment by Track
Measurement. ....
5.2.3.AzimuthAdjustment...
5.3 Bias Head
5.3.1Vertical Adjustment ....
5.3.2HeightAdjustment
5.3.3Horizontal Adjustment
5.4 Erase Head .
5.4.1HeightAdjustment
5.4.2Azimuth Adjustment
5.5 Model 3021X .
6.0 HEADALIGNMENTWITHOUTTANDBERG
TEST TAPES,MODEL 3041X
6.1 Playback Head .
6.1.1
HeightAlignment
6.1.2Azimuth Alignment . ...
6.2 Record Head .
6.3 Bias Head
6.4 Erase Head .
6.4.1Height Adjustment
6.4.2Azimuth Adjustment
6.5 Model 3021X .
7.0 TRACK CONTROL
7.1 Model 3041X .
7.1.1
Record Head
7.1.2
Erase Head .
7.1.3
PlaybackHead
7.2 Modell 3021X .
7.2.1Erase Head .
7.2.2Record Head
7.2.3 Playback Head
8.0ADJUSTMENT AND CONTROL
OF
THE AMPLIFIERS ... 11
8.1.1PlaybackLevel
Adjustment...... 11
8.1.2Adjustment
of Bias Current...... 11
8.1.3Record/PlaybackLevel Adiustment11
8.1.4Record/Playback
Curves ... ..... 11
8.1.5Distortion ........ 11
8.1.6
Control
of Playback
Amplifier.... 1'l
8.2
Tape Speed Control .... 12
8.2.1Using FrequencyMeter
or Counter12
8.2.2Using Transformer and Vacuum
Tube Voltmeter .. ...... . 12
8.2.3UsingTapeof Known Length .... 12
9.0 RECORD/PLAYBACK CURVES ..... 12
9.1 Readjustment ol Record/Playback Level 12
9.2Dlstortlon.... .........12
9.3 Control of Playback and Record
Ampliliers .... ... 12
9.3.1PlaybackAmplifier .... ... 12
9.3.2Record Amplifier ......... 13
10.0MoDrFtcATroNS ... 15
10.1 Modilications from 11511301230/240
V,
50/60 Hz Operation . .. . 15
10.2 Modification lrom Four-Track to Two-
TrackVersion... ......15
10.3 ComponentModificationin Series3000X15
11.LUBRTCATTON. ...... 15
12.0ILLUSTRATIONSWITH REFERENCE
PARTNUMBERS.. ..... 16
13.0
SPARE
PARTSLIST FOR MODEL3OOOX.. 22
13.1MechanicalParts ... ... 22
13.2Electrica!Components.. .... . 26
14.0TABLE OF TRANSISTORSUSEDIN
MODEL 3OOOX
15.0BLOCKDIAGRAMFORMODELSOOOX .... 28
16.0PRINTEDWIRINGBOARDSAND WIRING
DIAGRAM
16.1European Version
16.2U.S. Version
10
10
'10
10
11
11
11
11
11
4
4
4
4
4
4
5
6
6
6
6
7
7
7
7
7
7
8
8
8
I
I
9
9
9
9
9
I
9
9
9
9
I
I
10
10
10
10
10
10
10
10
10
10
10
10 28
30

1.0TECHNICALSPECIFICATIONS
POWERREQUIREMENTS: 115-130-230-240 V. 50 or 60 Hz operation.See chapter 10.1 for voltage
connections.
POWER CONSUMPTION: 45 watts.
MOTOR: Asynchronous.
TAPE SPEED: 17leips, 33/r
ips and 7tlzips.
TAPE: Maximumreel diameter7". Low NoiseTape only should be used for recordinq
and for adjustment
procedure.
WINDING
TIMES: 1200ft. of tape; 131min.
1800ft. of tape: 2t/z min.
PLAYINGTIME, Two track recordingon 1800ft. of tape.
MODEL3021X: Stereo Mono
7t/z ips: 48 min. 2 x 48 min.
33/,r
ips: 96 min. 2 x 96 min.
17laips: 192min. 2 X 192min.
PLAYINGTIME, Fourtrack recordingon 1800 ft. of tape.
MODEL3041X: Stereo Mono
71/zips: 2 x 48 min. 4 x 48 min.
33/rips: 2 x 96 min. 4 x 96 min.
17leips: 2 x 192min. 4 x 192min.
SPEEDTOLERANCE: -+ 1,50/0.
HEADS: Separateheads
for erasure,recording,
playback
and bias(Tandberg Cross-field).
FREQUENCYRESPONSE: 7t/z ips: 40-20.000Hz -+ 2dB
33/r
ips: 50-16.000Hz -+- 2dB
17e ips: 50- 9.000Hz -+ 2dB
Measuredto DIN 45511:
7t/z ips: 4O-22.0O0
Hz
33/rips: 40-18.000Hz
17laips: 40-10.000Hz
Amplifier
position:
50-18.000 Hz -+ 3 dB
ERASEAND BIAS 85,5 kHz. Distortionless than 0,5%.
FREQUENCY:
INDICATORS: Movingcoil meters.Optimum recording level: Deflectionup to 0 dB at maxi-
mum3o/o
distortion.
AMPLIFIERDISTORTION: RecordAmplifier:Recordingof a 400 Hz signat at 0 dB level,
gives less than
0,5
0/o
distortion
from recording
amplifier.
PlaybackAmplifier:0,3
0/o
distortion
at 0, 75 V output voltage.
TAPE DISTORTION: A tape recordedwith a 40OHz signal at 0 dB level,
gives less than 30/otape
distortion
in playback.
A tape recordedwith a 400 Hz signal8 dB below 0 dB on indicator,
gives less
than 0,8
0/o
tape distortionin playback.
Wl
cl
A
C
!(
fi (
i

-
a
WOW: W.
R.M.S.:
7t/z ips - better than 0,07
o/o
33/rips - better than 0,140/o
17le
ips - better than 0,280/o
DtN 45511:
71/z
ips - better than 0,1
o/o
33/r ips - better lhan O,2o/o
17le
ips - better than 0,40lo
CROSSTALK At 1OOO
Hz:
ATTENUATION: Mono ) 60 dB Stereo ) SOOA
INPUTS: Each channelhas the following inputs:
1. Microphone input for dynamic low impedance microphone. lmpedance:
200-700 ohm. Sensitivity
at 400 Hz: 0,1 mV. Maximum input level: 25 mV.
DINsocket.
US-version,
Telephone
jack.
2. Line input for high impedancesource. lmpedance: 1 Mohm. Sensitivityat
400 Hz: 100mV. Maximum input level:20 V. Phono sockets,LINE lNpUTS.
3. Line input for low impedancesource. lmpedance:
57 kohm. Sensitivity
at
400 Hz: 5 mV. Maxirnuminput level: 1 V. DIN socket RADIO: Pin 1, left
channel:Pin 4, right channel.
US-version:
Phono sockets LOW lN.
OUTPUTS: Emitterfollower outputs,RADIO DIN socket pins 3 and 5. US-version:
phono
SocKetS,
OUTPUT
LEFT and RIGHT.
Minimumload impedance:
100ohm. Output level:
A tape recordedwith 400 Hz
signal at 0 dB level, gives approx.0,75V in playback.HEADPHONES,
stereo
jack for connection
of headphones.
Stereojack is connected in parallelwith RADIOsocket pins 3 and 5. On US-
version stereo jack is connected parallel with phono sockets OUTPUT LEFT
and RIGHT.
SfGNALTAPE/NOISE Peak value measured
according to DIN 45511
at tape speed 71/zips and 5olo
WEIGHTED tape distortion:
(GERAUSCHSPANNUNG): 4-track 2-track
54 dB 56 dB
SIGNALTAPE/NOISE Peak value measured
accordingto DIN 45511
at tape speed 7t/z ips and 5o/o
UNWEIGHTED distortion:
(FREMDSPANNUNG): 4-track 2-track
51 dB 51 dB
SIGNAL/TAPE
NOISE: Measuredlinear R.M.S.
at tape speed 7'lz ips and 5o/o
distortion:
4-track 2-track
57 dB s7 dB
SfGNAL/TAPE
NOISE: Measuredat tape speed
7t/zips and 50/o distortion:
Wetonreo 4-track z-track
(lEC A-CURVE)
R.M.
S.: 62 dB 64 dB
Note: At 30/o
distortion all signal to noise ratio measurements(Signal/tape
noise)
are reducedby 2 dB.
DfMENSIONS: Length: 151/2"
(39,4
cm), heigth: 6t/2" (16,5cm) and depth: 123la"
(31,6cm).
WEIGHT: 20lbs(9,1
kg).

2.0MECHANICAL
ADJUSTMENTS
2.1Glutches
Control
of Winding Torque
Note: All controls and measurementsmust be car-
ried out with the tape recorder placed in
horizontal
position
and with empty reels only.
All controls are accomplishedas shown in
tig. 2.2which presents
two optimal modes of
control.Take-up turntableis shown. By con-
trol of supply
turntable,reversethe figure.
2.1.1
Take-up
Turntable
Normal
ForwardWinding
Torque
Set the operating lever to Normal Forward drive
position
v.riththe motor running.The torque is read
in table tig. 2.3,pos. 1. Ensure that the clearance
991017 9910r3 261841 2673?38 2640834' 991009
Fig. 2.1.
between the polyurethane
friction pads under the
turntable and friction disc 991009 lays between
0,5--O,9 mm (0.02"-0.035"). lf necessary, adjust
screw
A as shownin fig.
2.1.
2.1.2
Take-upTurntable
Fast ForwardWinding Torque
The torque is read in table fig. 2.3, pos. 3. lf the
torque deviates
from the specifications
in the table,
check and, if necessary,
alterthe pressure
of spring
263737B.
Ensurethat there is a clearance
betweenthe studs
on bushing2640834
and lever991013.
See fig. 2.4.
2.1.3
SupplyTurntable
Tape
Tension
The torque is read in table fig. 2.3, pos 2.
2.1.4
SupplyTurntable
Fast Reverse WindingTorque
The torque is read in table fig. 2.3, pos. 3. lf the
torquedeviates
lrom the specifications
in the table,
check and, if necessary,
alterthe pressure of spring
2618054.
See fig. 2.5.
The difference between Fast Winding Torque and
Fast Reverse Winding Torque should be less than
1309
(measured
at 30 mm radius), or 509 (measured
at 80 mm radius).lf necessary,alter the pressure ot
spring261805A
(fig.
2.5),
or spring2673738
(fig.
2.1).
*1
Pot
2
Pot
3
,l
I
a
I
i
(
i
t
t
0.5
- 0,9mm
(0.02t'
- 0.035'r
)
30mm radius 80mm radius
Fig 2.2.

Tablefor WindingTorques
Torque
at
30mm
radius
Torque
at
80 mm
radius
159- 309-
tit winding
Pos
2 taperensron
Fastwinding
Fig.2.3.
* Aftera longer
periode
of continuousoperation,
an
increaseof the torque by 2G-30 0/o
is considered
as normal. C
Ensure
that the torque is within the specifications
in the table by running
the tape recorder in verti-
cal position,
and with a tull 7" reel on take-up
turntable.
o- 8g
Pos
3909-250g
t
I
264930 99101 ?
Fig. 2.6.
2.2 Brakes
See fig. 2.6
Set the operating lever to Normal Forward drive
position. Check that the clearance between the
brake pad and the turntableis approx1 mm (0.04").
lf necessary,
adjust screw D.
Set the operatingleverto Fast ForwardWinding or
Fast ReverseWinding position respectively.
Ensure
that the clearancebetweenscrew C and the bottom
of the hinged
delrinparts on operatingarm 991017
laysbetween
0,5-1 mm (0.02"-4.O4"
). lf necessary,
adjust screw C.
The adjustment
procedure
is equal for both turn-
tables.
251489
A@
Fig. 2.7.
min 0,lmm
(0.004,')
Fig. 2.4.
261805A
Fig. 2.5.

2.3PressurePadAdjustment
Set the operating lever to Neutral position. The
clearance between the pressure pad 990325and the
tape rest 254844A
should be approx. 6,5 mm (tlr") as
shown in fig. 2.7.
lf necessary,adlust the clearance
by bending the arm 254025with a pair of pliers.
See fig. 2.8.
Fig. 2.8.
Set the operating lever to Normal Forward drive
position.
The pressure at the pad againstthe tape
restshould
be80
g (2,8
ozl -+ 10
0/0,
measuredon the
end of the pressurepad arm 254025.
See fig. 2.9.
lf necessary,adjust the pressure by bending the
spring
268062
with a pairof pliers. Seefig. 2.10.
2.4 End Stop Mechanism
2.4.1Tape Feeler Tenslon
The feeler tension againstthe tape should lay be-
tween 8 and 10
g (0.28-0.35oz) in drive winding
modes.Adjustmentof the tension is accomplished
by tighteningor slackeningthe spring 243990.
See
lig. 2.12.
Fig.2.10.
2.4.2Adjustmenl of Tape Feeler
See fig. 2.11and 2.12.
Settheoperating
leverto NormalForwarddriveposi-
tion.The mains switchis set to ON.No tapeshould
be inserted.
The tapefeelerwill therefore restin the
positionwhere the motor is switched off. Push the
feeler
slowly
throughthe guide
post.
Whenthe rear
side of the feeler is min. 0,5 mm (0.02")
from the
polished tape contact surface of the guide post,
loosen screw F, and move the microswitch slowly
until the motor startswhen the tape feeler is in the
position specified above. Then tighten the screw.
When the tape feeler is released,
the microswitch
shouldopen,and switch off the motor currentwhen
the space between the tape feeler and the arm
266741
is minimum
0,5mm (O.O2"). Seefig. 2.12.
Check the switching on and-off positions of the
tape feeler at both fast winding modes.
I
l1
a
(
t
a
I
a
zzl
/:\
(@,
12.82
ozl !
l,
a-\\
',-/
80s
252754
tM3l4
Fig. 2.9.

Adjustment distance
Justeringsavstand minimum 0,5 mm (0,02rr)
266741
Min 0,5 mm
(o.02"
l
Fig.2.12.
243990
Fig.
2.11.
3.0ALIGNMENT
It is importantthat the contact between the tape
and the heads on the tape recorder is good. To
obtain optimum resultson new tapes (Low Noise),
the tape should be run through the tape recorder
approx.5 times at normal speed to have the tape
polished
before measuring the frequency response
and the signal-to-noise
ratio.
v 3.1Demagnetizang
Demagnetize
the heads and adjacent parts before
aligning
the heads.
Movethe demagnetizing coil slowly past the head
gapat shortdistance.
The headsurfacemust on no
accountbe touched,
as scratchesare detrimentalto
the performance. Hold the demagnetizing
coil near
the capstanfor a few seconds.
Start
the tape recorderand hold the demagnetizing
coil right abovethe flywheel.
Note: Do not switchoff the demagnetizer
until it is
at least3 feet awayfrom the tape recorder.
3.2 Bias- and EraseCircuits
3.2.1 Oscillalor Frequency
Connect a calibrated long wave receiver(tuned to
256.5kHz),frequencymeteror frequency
counter
to
the oscillator by means of a pick-up loop placed
around the erase head. Adjust the oscillator
frequencyto 85.5 kHz by meansof C 508.
3.2.2 Erase Voltage
Set the tape recorder for stereo recording and
connect a VTVM to upper half of the erase head
by meansof a low-capacitance
probe. The voltage
should be 80-120 V. Then check ihat the same
voltageappearsacrosslowerhead-half.
Set the tape recorder for recording on channel L
and check the voltage across upper half of the
erase
head.
Thedeviationfromthe voltage measured
in stereo recording
shouldnotexceed10
V. Proceed
similarlyfor recordingon channel R.
3.2.3 Bias Current
Set the tape recorder for stereo recording and
measurethe voltage across upper half of the bias
head by means of a VTVM. Adjust the voltage to
22 Y by meansof R 501 . Check the voltage across
lower head-halfand adjust to 22 Y by means of
R 502. Demagnetize heads and tape path.

4.0 TAPE PATH
4.1 Visual Check
Load the recorder with a tape, and move the
operating lever slowly to the normal forward drive
position.
Check that the bias head neither touches
the height adjustment screws (C) on the record
head base plate, nor pressesthe tape against the
record head. Also check that the bias head is
parallel
to the record head.
Operate the start/stop knob, and check that the
tape runs within the rims of the pressure wheel
rubber without flickering on neither side of the
pressure wheel. Check that height positioning of
the guide posts is correct. lt can be toleratedthat
the tape touches the flanges of the guide posts
when the recorder is in normal forward drive, or
as the drive mechanismis engaged.The tape must,
however,
by no means bulge at the flanges.
4.2MechanicalAdjustment
ofTapePath
Prior to the electricaladjustmentof the heads,it is
essential to make the tape run without sideways
movement
throughthe path.
Put a tape free from damages on the recorder in
normal way and set the operating lever to normal
forward drive position.
Adjust the azimuth position
of pressure roller 990334 with a screw driver as
shown in tig. 4.2, until the tape is running evenly
through the rest of the tape path, slightly touching
one of the flanges of the guide post 1 located
adjacent
to the capstan.
Align guide posts2, 3, and 4 similarly.
lf necessary,
adjust
pressure
roller
spring
234478to make
thetape
run perfectly.
990334
Fig. 4.2. Azimuth adiustment ol pressureroller.
(
5
$,
a
tc
5.
P
pl
al
al
hr
o
el
tt
5,
P
p
a
b
ir
E
5
Ir
ft
tt
h
n
v
tt
4
I
F
C
(
c
v
I
(
I
II
MD
Fig. 4.1. Tape path adiustment screws.