TANDBERG 6000X Series User manual

JANDBERG
Serles 6OOOX
SER\/IGE MANUAL
:'.:'-"-!,..,r/
g /r l
3(r i.- I l
:t(.;iJ,i i
l. ,
TANDBERGS RADIOFABRIKK A/S

-\
t'>,
CONTENTS
1.0Mechanical Adjustments
1.1 Clutches
1.1.1Take-upT\rrntable
1.1.2
Supply
T\rrntable
1.2 Brakes
1.3 PressurePadAdjustment
1.4 EndStop
Mechanism
1.4.1TapeFeelerTension
1.4.2Adjustment
of TapeFeeler
Alignment
2.1 Demagnetizing
2.2 Bias-
and
EraseCircuits
2.2.1OscillatorFrequency
2.2.2
Erase
Voltage
2.2.3Bias
Current
TapePath
3.1 Visual
Check
3.2 MechanicalAdjustmentof Tape
Path
HeadAlignment
with TandbergTestTapes
Model
6041X
4.1 PlaybackHead
4.1.1
Height
Adjustment
4.1.2
Azimuth
Adjustment
4.2 Record Head
4.2.1HeightAdjustmentby
VisualInspection
4.2.2
Height
Adjustment
by
Track Measurement
4.3 BiasHead
4.3.1VerticalAdjustment
4.3.2
HeightAdjustment
4.3.3
HorizontalAdjustment
4.4 EraseHead
4.4.1HeightAdjustment
4.4.2 AzimuthAdjustment
4.5 Model6021X
HeadAlignment
WithoutTandbergTestTapes,
Model
6041X
5.1 Playback Head
5.1.1HeightAlignment
5.1.2AzimuthAlignment
5.2 Record Head
5.3 BiasHead
5.4 EraseHead
5.4.1HeightAdjustment
5.4.2AzimuthAdjustment
5.5Model
6021X
7.0 Adjustment
andControlof theAmplifiers 9
7.1.1PlaybackLevel
Adjustment I
7.1.2
Adjustment
of BiasCurrent 9
7.1.3
RecordLevel
Adjustment 9
7.1.4
Record/PlaybackCurves I
7.1.5
IndicatorAdjustment
in RecordMode 9
7.1.6Distortion I
7.1.7
IndicatorAdjustment
in Playback
andAmplifier Modes 9
7.1.8
Controlof the Playback
Amplifier I
7.2 TapeSpeed
Control 10
7.2.1
UsingFrequencyMeter
or Counter 10
7.2.2
UsingTransformer
andVacuum
Ttrbe
Voltmeter
7.2.3
UsingTapeof Known Length
8.0 Adjustment
of theAmplifiers,without
Tandberg
TestTapes
8.1 Playback
andRecordLevel
Adjustment
8.2 Record/PlaybackCurves
8.3 Readjustment
of RecordLevels and
Indicators 10
8.4 Distortion 10
8.5 Controlof PlaybackandRecordAmplifiers11
8.5.1PlaybackAmplifier 11
8.5.2 RecordAmplifier 11
8.6 Pick-up
AmplifierCurve 11
8.7 Limiter 12
8.7.1
Adjustmentof LimitingThreshold 72
8.7.2
Adjustmentof ReleaseTime 12
9.0 Modifications
9.1 Modification
from 230/115V
50Hz
to 230/115V
60Hz operation
9.2 Modification
from Four-Track
to Two-Track
Venion
9.3 ImportantElectricalModifications
Introduced
in Series6000X
10.0Lubrication
11.0Illustrations
with Reference Part
Numbers
12.0 SpareParts
List for Tandberg
Tape
Recorder6000X
12.1MechanicalParts
12.2Screws,
Washers,NutsandCirclips
12.3ElectricalComponents
12.3.1Transistors
12.3.2Diodes
12.3.3Rectifier
1
2.3.4
Trimming
Capacitor
12.3.5Poientiometers
12.3.6Heads
12.3.7Transfonners
13.0 Transistor
andDiode
Identification
14.0 BlockDiagram Series
6000X
15.0 PrintedWiringBoardsand
lViringDiagram
2.0
3.0
4.0
I
I
I
tt
I10
10
10
10
10
t2
13
5.0 13
13
I4
1.7
77
2L
21
2L
22
22
9'
,t
22
22
23
23
24
6.0 Track
Control
6.1 Model
6041X
6.1.1RecordHead
6.1.2
EraseHead
6.1.3PlaybackHead
6.2 Model 6021X
6.2.1EraseHead
6.2.2
Record
Head
6.2.3Playbacktlead
^

1.0
1.1 MECHANICALADJUSTMENT
Clutches
1.1.1
Take-upTurntable
Normal Forwarddrive
Set the operating lever to normal forward drive position
with the motor running. Ensure that the clearance
between the polyurethane friction pads under the turn-
table and friction disc
991009 laysbetween
0,5-0,9 mm
(0.02"-0.035"). If necessary,adjust
screw
A as shown in
fig. 1.1.
1
991034
0,5-0.9 mm L
{0.02"-0.35") I -
Control of Winding Torque
Note: All controls and measurements
must be carried out
with the tape recorder placed in horizontal posi-
tion and with empty reels
only.
The control is accomplished as shown in fig. 1.2, which
presents
two optional modes of control.
Fig. 1.2 Control of winding force. Normal forward drivemode.
FastForwardWinding
Control of FastWinding Torque
Set the operating lever to fast forward winding position.
The control is accomplished asshown in fig. 1.3, which
presents
two optional modes of control,
-
il
991017 991013
Fig.1.1 .rl
30 mm radius
Force:
4O-80g
80 mm radius
While measuring, the reel should beallowed to havea
slow rotation. The instrument should follow the
movement in a straight line towards the tape recor-
der.
Notc: After a longer period of continuous
operation, an increase of the torque by
20-30V" isconsidered as normal.
Force:
15-30g
.arl
4
+iI

30 mm radius
Fig. 1.3 Control of fastwinding torque. Fastforward winding mode
80 mm radius
\^
\'t\
If the torque deviates
figure, check and, if
spring
2673738.
from the specifications in the
necessary, alter the pressure of
Ensurethat there is a clearancebetweenthe studson
frictiondisc991010
and
lever
991013.
Seefig.1.4.
1.1.2SupplyTurntable
Control
of Tape
Tightening
Tension
Settheoperating
leverto normal
forwarddrive
position.
Thecontrol isaccomplished
asshown
in fig. 1.5,
which
presents
two optionalmodes
of control.
min0,1 mm
(0.091")
991017991013 991OlO 261805
Fig. 1.4
\F
Force:
90-2509
30 mm radius
Force:
O-99o
80 mm radius
While measuring, the reel should be allowed to have a slow rotation. The instrument should follow the
movement in a straight line towards the tape recorder.
F
Fig. 1.5 Control of tape tightening tension. Normal forward drive mode.

Fast
Reverse
Winding
Control of Fast Reverse
Winding Torque
Set the operating leverto fast reverse
winding position.
The control is accomplished
as
shown in fig. 1.6, which
presents
two optional modes
of control.
30 mm radius 80 mm radius
Force:
90-250g
Force:
240-67 0g
Fig. 1.6 control of fast reverse
winding torque. Fast reverse
winding mode
J
1F{
If the torque deviates from the specifications in the
figure, check and, if necessary, alter the pressure of
spring261805.
Seefig. 1.7.
The difference between Fast Winding Torque and Fast
reverse
Winding Torque should be lesi than 180 g (force
measured
at 30 mm radius),
or 50 g (measured
at g0 mm
1a--dius!
If necessary,
alter the p.esiu.e of spring 261g0b
(fig. 1.7),or spring2673738 (fig. 1.1).
1.2
Brakes
See
fig. 1.8.
Set the operating lever to normal forward drive position.
Check that the clearancebetween the brake pad^
and the
tumtable is approx. 1 mm (0.04"). If necesiary,
adjust
screwD.
Set the operating lever to fast forward winding or fast
reverse winding respectively. Ensure that the clearance
between screw C and the bottom of the hinged delrin
partson operatingarm 991012 lays between 0,b-1 mm
(0.02"-0.04"). If necessary,
adjust
screw
C.
The adjustment prosedure isequal for both turntables.
1.3
Pressure
Pad
Adjustment
Set the operatinglever
to neutral position. The clearance
between the pressure pad 990325 and the tape rest
254844 should be approx. 6,5 mm (1/4") as
shown in
fig. 1-.!. If necessary,
adju,st
the clearanceby bending the
arm 254025with a pair of pliers.
Seefig. 1.10.
Set the operating lever to normal forward drive position.
The pressure of the pad against the tape rest slould be
80 g (2.8 oz) ! tO 7o, measured on the end of the
pressure pad arm 254025. See fig. 1.11. If necessary,
adjust the pressureby bending the spring 268062 with-a
pair of pliers. Seefig. 1.12.
Fig. 1.7
.)fl
Fig. 1.8 991Ol7(0.02"-0.04") i)c

I
-
;
251489
A
6,5
mm
(1/4").
Fig. 1.9
Fig.
1.10
1.4 End StoP Mechanisrn
1.4.1
TaPe
Feeler
Tension
The feeler
tension
against
the tape
shouldlay.between
8
;; i;'; to.ie-o.fs o') in a'ii" and.
windingmodes'
Adiustment of the tensioitii accomptishgd-u.v
tightening
;'"i;t;;;iline.p'l"g 243eeo'
see
fig' 1'14'
1.4.2
Adlustment
of TaPe
Feeler
See
fig.
1.13
and
1.14'
S.; il: operatinglever in normal forward driveposition'
or forward or reverse
winding' Th-e
mains.switch
issetto
bN."ff;di .r'"ura ;;-;;e;hd' rhe tape reeler
will
ir,i;"i';" "T;-i; *,J-poiiti"rr Yh:T"--ll3 motor is
ffi;; oii. p.ro tt'" t!"tet slowlv-through the guide
oost. Whenthe rear tla" "f the feeler-is
min' 0'5mm
id;t";'ii"* ttt" porislea-"ontact surface
of the guide
i"".","1t*'-"";#qt.l""F*iml*n3iiil".n';"i
not, loosen screw r'.i
until the motor startJ- when the tape feeler is in the
",i.iirJii""i""iri"a "u"u"' irten tighten
-
the
screw'
When
fi;;';;;; ii"r"t it released,
the
microswitch
should
open'
and stop the motor when the spacing.
between the tape
feeler and the arm 244694A- is minimum ( 0'5 mm
(0.02").
See
fig. 1.14.
80g (2.82
oz)1 t0%
@
Fig.
1.11
Min0,5
mm
{0.02")
F\ !f Fig.
1.13
DF Fig.
1.12 Fig. 1.14

2.0
ALIGNMENT
It is-important that the contact between the tape and the
heads on.the tape recorder is good. To obtain optimum
resultson new tapes, the tape should be run through the
tape recorder approx. 5 times at normal speed to have
the tape polished before measuring the friquency res-
ponse
and the signal-to-noise
ratio.
2.1Demagnetizing
Demagnetizethe heads
and adjacent parts before aligning
the heads.
2.2
Bias-
and
Erase
Circuits
2.2.1 Oscillator Frequency
Connect a calibrated long wave receiver (tuned to 256.5
kHz), frequency meter or frequency counter to the
oscillator by means of a pick-up loop placed around the
erase
head. Adjust the oscillator frequency to 8b.b kHz
by mensof C404.
2.2.2 Era* Voltage
Set the tape recorder for stereo recording and connect a
VTVM to upper half of the erase head by means of a
low-capacitance
probe. The voltage should be 80-120V.
Then check that the same voltage appears across lower
headhalf.
Set the tape recorder for recording on channel L and
check the voltage across upper half of the erase head.
The deviation from the voltage measured in stereo
recording should not exceed 10V. Proceed similarly for
recording on channel R.
2.2.3 BtasCurrent
Set the tape recorder for stereo recording and measure
the voltage across upper half of the bias head by means
of a VTVM. Adjust the voltage to 22Y by means of
R407. Check the voltage across lower head-half and
adjust to 22Y by means
of R410. Demagnetizeheads
and
tape path.
3.2 Mechanical
adjustment
of tape
path
Prior to the electrical adjustment of the heads, it is
essential to make the tape run without sideways move-
ment through the path.
Set the operating lever to neutral position. Unscrew the
screw holding latch 215563 to allow the latch to settle in
the position determined by spring 284478. Then tighten
the screw. The spring pressure will now be equal against
the_ upper and lower points of pressure roller pivot
247941.
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
99033.1with a screw driver asshown in fig. 3.2, until the
tapg ls running evenly through the rest of the tape path,
$ightly touching on-e of the flanges of the tape post 1
located adjacent to the capstan.
Align guide post 2, 3, and 4 similarly. If necessary,
adjust
pressure roller spring 234478 to make the tape run
perfectly.
-
-<l
3.0TAPE
PATH
3.1
Visual
Check
Load the recorder with a t-ape,and move the operating
lever dowly to the normal forward drive position. Checi
that the bias head neither touches the height adjustment
screws(C) on the record head base
plate, nor presses
the
tape against the record head. Also check thit the bias
head is parallel to the record head.
Operate the start/stop button, 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
cor:ect. It can be tolerated that the tape touches the
flanges of the guide posts when the recorder is in normal
forward drive, or as the drive mechanism isengaged.
The
tapemust, however, by no meansbulge at the flanges.
ln
IHMD
Fig. 3.1 Tape path adjustment screws
Fig. 3.2 Azimuth adjustment of pressure
roller
rll'\

--
(?4;
4.0 HEADALIGNMENTWITH TANDBERG
TESTTAPES,MODEL
6041X
4.1Playback
Head
Set the recorder for stereo playback and connect a
VTVM to eachone of the phono outputs.
4.1.1 HeightAdiustment
Play Tandberg test tape No. 1. This is a full track
prerecorded tape with 1.000 Hz recorded at 7 ll2 ips,
and with the area corresponding to track 3 reduced by
approx. 30 dB. Adjust the height of the playback head
by means of the screws (A) until minimum output is
obtained from track 3 (channel R), while endeavourlng
to maintain the headfront parallel to the tape.
4.1.2 Azlmuth Adjustment
Play Tandberg test tape No. 2. This is a full track
prerecorded tape with 10 000 or 15 000 Hz recorded at
7 tl2 ips. Adjust the azimuth position of the playback
head by means of the screw (B), until maximum
indication on the VTVM is obtained.
4.2 Record Head
4.2.1 Height Adiustment by Visual Inspection
Insert a new tape, and start the recorder in normal
forward drive. Check visually that the tape appears to
run parallel with the upper track of the record head, with
a play of approx. 0,1 mm (4 mils). If necessary,
adjust
the height with screws
(C) fig. 3.1, while endeavouring to
maintain the headfront parallel to the tape.
4.2.2Heighl Adiustment by Track Meaurement
Record in stereo, well above normal level, first in one
direction, then in the opposite. Cut off a length of tape
and dip it into a solution of fine grained iron oxyde
powder and alcohol (Magna See). The tracks will then be
visible as four dark stripes with spacingsin lighter shade.
Fig.6.1 shows the correct pattern on the tape and the
patterns obtained when the head is positioned either too
high or too low.
Adjust as above and perform a new track measurement.
4.2.3 Azimuth Adiustment
Load a new tape into the tape recorder and record at
tape speed 7 Ll2 ips, a 15 000 Hz signal in stereo.
Depress
both playback buttons and turn both playback
volume potentiometers to maximum. Adjust both Line
Record l,evel knobs for approx. 150 mV at the outputs.
Adjust the record head azimuth screw for maximum
output from both channels simultaneously or best
compromise.
4.3
Bias
Head
4.3.1 Vertical Adiustment
Move the operating lever slowly to the normal forward
drive position and check that the head fronts of bias-and
record heads are parallel. If necessary, bend the arm of
the biasheadasrequired.
4.3.2 HeightAdjustment
Set the tape recorder in record mode, and unscrew the
locking screw (H) fig. 3.1, about 1/2 turn. Connect a
VTVM acrosseach one of the record head halves.Move
the bias head up or down by means
of adjustment screw
M for the highest possible reading on the voltmeter.
Check that the tape runs freely in the groovein front of
the bias head and that there is sufficient clearance
between the bias head and the mounting plate for the
record head. The height position of the bias head is not
critical, and if the clearance between the bias head and
the mounting plate for the record head is insufficient,
raisethe biashead slightly.
4.3.3 Horizontal Adjustment
Connect a VTVM across each one of the record
headhalves, and set the tape recorder for stereo record-
ing. Insert a screwdriver in groove I, ref. fig. 3.1, and pull
the bias head to the right.
Then pull the bias head carefully by means of the
screwdriver towards the left hand side.
Induced voltage (bias) in recording head increasesto a
maximum. Continue pulling the head towards left side
until the bias is reduced by 10-15 7o
below maximum.
When the position has been found, thigthen the screw
(H) while maintaining correct horizontal position of the
head. Then recheck the output voltage. If a noticeable
change has occured, the horizontal procedure has to be
repeated.
4.4EraseHead
4.4.1 Height Adjustment
By visual inspection, check that approx. 0,25 mm (10
mils) of the upper half of the erasehead isvisible above
the tape. Insert Tandberg test tape No. 9 and record a
4OO Hz signal at 7 Ll2 ips well above normal level on
channel R (track 3). Dip the tape in a solution of fine
grained iron oxyde powder and alcohol (Magna See
solution). Check that the recorded track is positioned in
centre of the erasedtrack. Make surethat no parts of the
adjacent tracks are erased, see fig. 6.2. If necessary,
adjust the height of the erase head by means of the
screws (K) and (L) ref. fig. 3.1, and repeat the above
check.
4.4.2 Azimuth Adlustment
Check that the head front of the erase head is
perpendicular to the mounting plate. If necessar5r,
adjust
azimuth position by meansof the screws
(K) ref. fig. 3.1.
This adjustment is not critical.
4.5Model6021X
The alignments specified in para. 4.0 are valid for the
model 6021X with the exception of paragraph 4.1.1,
which is supensededby 5.1.1 and paragraph4.2.1, which
issuperseded
by 6.2.2.
$'rF
D{^

5.0 HEAD ALIGNMENT WITHOUT
TANDBERG
TEST
TAPES,
MODEL
6041X
5.1Playback
Head
5.1.1 HeightAlignment
The height of the playback head is aligned by the height
adjustment screws
(A), ref. fig. 3.1. The upper edgeof
the tape shall run flush with the upper part of the head
lamination for channelL.
5.1.2Azimuth Alignment
Play back a standard azimuth alignment tape with a
VTVM connected to each output. Adjust the position of
the playback head by the azimuth adjustment screw (B)
ref. fig. 3.1, until maximum reading is obtained on the
output meters.
5.2Record
Head
Follow the instructions given under paragraph 4.2.
5.3Bias
Head
Follow the instructions givenunder paragpaph
4.3
5.4Erase
Head
5.4.1 Height Adjustment
The height of the erase head is aligned by the height
adiustment screws (K and L) ref. fig. 3.1. Approx. 0'25
min tfO mils) of the ferite core for the upper track of
the erasehead should be visible above the tape.
5.4.2 Azimuth Adjustment
Align the azimuth position of the erase head by the
azimuth adjustment screws(K). The erasehead should be
parallel with the mounting plate for the heads. The
azimuth position of the erase
head is not critical.
5.5
Model6021X
The alignments specified in paragraph 5.0 are valid for
model 6021X with the exception of paragraph
5.2 which
is superseded by 4.2. Paragtaph 4.2.1 is superseded by
6.2.2.Paragraph
5.4.1issupersededby 6.2.1.
6.0
TRACK
CONTROL
6.1
Model6041X
6.1.1 RecordHead
Record a 1.000 Hz signalfrom a generator well above
optimum recording
levelin stereoA-test
on tracks1 and
3 for approx. 5 seconds.
Turn the tape around and make
a similar recording on tracks 4 and 2. Cut the tape and
dip it into amixture of fine glained iron oxyde powder
and alcohol (Magna
Seesolution) to make the recording
visible. The spaces
between the recorded tracks should be
distributed equidistant across the tape, ref. fig.6.1.
Readjust the height position, if necessary,
and recheck
the azimuth alignment.
6.1.2The Erase
Head
Insert a full-track prerecorded tape and record a 1'000
Hz signal from a generator, well above optimum record'
ing level in mono on track 3 (channel R). Cut the tape
and dip it into the Magna Seesolution. Check'that the
prereeorded track is in the centre of the erasedarea,
ref'
fig.6.2. Adjust the vertical position of the erasehead if
necessarv.
6.1.3 Playback
Head
Record a 1.000 Hz signal on track 1 (channel L) and a
500 Hz signal on track 3 (channel R) at optimum
recording levels. Turn the tape around and play back
track 2 (channel R) at maximum volume. No signal
should be heard. Raise
the playback headif the 1.000 Hz
signal is heard. Lower the playback head if the 500 Hz
signalis heard. Recheck the azimuth position.
,-t
tn
-
-
Too high
Correct
Fig. 6.1 Track measurement of record head
-
-Too high
Correct
:
:
Too low
Fig. 6.2 Track measurement of erase
head
Too low
tro

l)a
6.2
Model
6021X
6.2.1Erase
Head
The height of the eraseheadisalignedby the adjustment
screws
(K and L) ref. fig. 3.1. Record a 1.000 Hz signal
in stereo well above optimum recording level on a
full-track prerecordedtape. Dip the tape in the Magna
See solution and check that the tracks are distributed
symmetrically acrossthe tape. Readjust the erase and the
record heads,if necessary.
6.2.2RecordHead
The height of the record head is aligned by the height
adjustment screws (C). Record a 1.000 Hz signal in
stereowell aboveoptimum recording level on a full-track
prerecordedtape. Dip the tape in Magna See
solution and
check that the tracks are distributed symmetrically
acrossthe tape. Readjust the eraseand the record heads,
6.2.3
Playback
Head
The height of the playback head is aligned by the height
adjustment screws (A). The tape shall run parallel with
the upper edgeof the lamination for channel L. Readjust
the azimuth position if necessary.
7.0ADJUSTMENTAND CONTROLOF THE
AMPLIFIERS.
7.1.1PlaybackLevelAdiustment
Connect a VTVM to eachone of the phono ouq)uts, and
tum the playback volume controls to maximum. Set the
recorder for 7 tl2 ips playback of Tandberg test tape
No. 4 and adjust R150 (L) and R250 (R) for 1.5V
readingon both vacuum tube voltmeters.
7.1.2Adlustmentof BiasCurrent
Insert a new reel of good quality tape (Low Noise).
Connect a VTVM to Line Output terminals, and signal
generator to Line Input terminals and set the generator
for 1.000 Hz and 0.5 volt. Set the Output Level Controls
to maximum and adjust the Record Level Controls to
150 mV deflection on VTVM. Set the tape recorder for
stereo recording. Adjust R407 to maximum deflection
on left channel VTVM, and R410 to maximum on right
channelVTVM.
Note: The 2-track model is also equipped with individu-
^ ally tuned bias- and erase heads. The values of
il {T--\ C40?, C408 and C126. C226 are labelled on the
' bias- and erase heads, respectively. The capaci-
tances are given in pF. Upper number refers to
uppertrack.
7.1.3RecordLevelAdjustment
Inserta new tape and record a4OOHz signa.latT l12ips
in A-test. Adjust the recording levels for a VTVM
indication of 1.5V at both phono outputs. Depressthe
playback buttons (B-test) and adjust the recording
current by meansof R108 (left channel)
and R208 (right
channel)
until anoutput voltage of 1.5 V isobtained.
7.1.4 Record/Playback
Curves
Ref. para. 8.2 for adjustment
playback curves. and control of record/
7.1.5 Indicator Adjustment in Record
Mooe
Setting of levels,the sameasin paragraph 7.1.3.
Adjust R124 for a 0 dB reading on left record level
indicator and set F-224 for the same reading on right
indicator.
Release both playback buttons and check that the
output voltage isstill 1.5 V for both channels.
7.1.6 Distortion
Connect signal generator 400 Hz, 0.5 V and distortion
meter to outputs. Record in B-test on both channels.
Adjust Record Level controls to 0 dB deflection on
indicators. Check distortion to be less than 37o. lf
distortion exceeds 37o, readjust recording level and
indicator,ref. paras.
7.1.3and 7.1.5.
7.1.7 Indicator Adjustment in Playback and Amplifier
Modes.
Set the tape recorder in stereo preamplifier mode, and
check that the vacuum tube voltmeters read 1.5V on
phono output. Adjust P"422
(L) and R445 (R) until both
level indicators read 0 dB.
7.1.8 Control of PlaybackAmplifier
Play back Tandberg test No. 3. This is a full track
prerecorded tape with the following frequencies:
250-10.000-5.000-
1.000-
10O-5O-
25OHz
recorded
at 7 7
|
2
ips tape speed. The tape conforms with the N.A.B.
standard.
The output tolerances
are:
10 kHz: 0 - + 4 dB,
5 kHz: + 1 - + 3 dB. The other frequencies have
tolerances t 2 dB. The difference in levelbetweenthe
two channelsshouldbelessthan 3dB.
rF