Teac A-6100 User manual

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CONTENTS
1. GENERAL DESCRIPTION . 1
2. SPECIFICATIONS . 2,3
3. TOOLS FOR TESTING AND MAINTENANCE . 4
4. TEAC TEST TAPE -YTT SERIES- . '5
5. TAPE TRANSPORT PARTS LOCATION . 6
6. PARTIAL DISASSEMBLY . 7
7. LINE VOLTAGE AND FREQUENCY CONVERSION . 11
8. HEAD ALIGNMENT . 12
9. MEASUREMENT AND ADJUSTMENT -MECHANICAL- . 14
10. A-6100 ELECTRICAL ADJUSTMENT -GENERAL NOTICE- . 19
11. MEASUREMENT AND ADJUSTMENT -ELECTRICAL- . 20
12. A-6300 ELECTRICAL ADJUSTMENT -GENERAL NOTICE- . 31
13. MEASUREMENT AND ADJUSTMENT -ELECTRICAL- . 32
14. SERVICING AND MAINTENANCE ... 42
15. LIST OF LINE VOLTAGE AND FREQUENCY (Hz) USED AROUND THE WORLD. 44
16. TEAC DECIBEL TABLE . 45
17. TROUBLESHOOTING .46,47
18. LEVEL DIAGRAMS . 49,50
NOTE
When placing an order for parts, please refer to the PARTS LIST
and PRICE LIST FOR PARTS which are printed separately from this
manual.
1. File the PARTS LIST manual together with this SERVICE MANUAL;
future TECHNICAL INFORMATION SHEETS should also be kept with these.
2. Use the PARTS LIST manual and the PRICE LIST FOR PARTS when
ordering replacement parts from TEAC Corp.

1. GENERAL DESCRIPTION
The TEAC A-6100/A-6300 is an excellent home entertainment stereo tape deck,
built to semi-professional standards with 3 motors, 4 heads, two (selectable)
meter scale ranges, and completely push-button controlled operation. Accepts
either 7" or 10-1/2" reels, and has tape speeds of 3-3/4 ips and 7-1/2 ips
(A-6300) or 7-1/2 ips and 15 ips (A-6100). Special features include switch-
selected Bias and Equalization; two Line Input and two Line Output jacks
per channel; facilities for (optional) remote/timer controlled operation;
and special features for the A-6100 such as 4-Track playback; MIC ATT; and
choice of 0.3 V or 0.775 V "0 VU" level at the OUTPUT jacks.
Although the A-6100/A-6300 internally appears to be similar to other TEAC
models (esp. A-4300), significant differences require consulting this manual
before any attempt to service the deck. This A-6100/A-6300 Service Manual/
Parts Manual contains adjustment and alignment information, part replacement
reference, and other information about obtaining new parts.
If adjustments or repair procedures are not sufficiently clear or seem too
difficult to accomplish, or for more detailed technical information, you may
contact the nearest TEAC Distributor, a TEAC affiliated subsidiary corporation,
or the TEAC Corporation. TEAC addresses are found at the back of this manual.
FEATURE COMPARISON CHART A-6100:: A-6300
Tape Speed (ips) 15. 7K
VA. 3X
Automatic Reverse play
NO YES
Counter Repeat (Playback)
NO YES
Memory ADT0-ST0P
YES
NO
Mic Attenutor
YES
NO
Peak Level Indicators
YES
NO
Flip Open Head Housing
YES NO
0 VD Marker for OUTPUT
YES
NO
Playback Track Selector
YES
NO
Output Level Selector
YES
NO
Other minor design changes were also incorporated for specific
differences in parts and circuitry please consult the Parts List
and Schematic Diagrams.
DIMENSIONS
o o
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»j
•V
- 1 -

2-1. SPECIFICATIONS
ELECTRICAL
ELECTRICAL
A-6100
FREQUENCY RESPONSE: Overall from recording INPUT to playback OUTPUT
lSlps ••• 40Hz'v26kHz ±3dB
7-l/2ips ••• 40Hz'v24kHz ±3dB
(Measured at 20 dB below the Specified Level)
INPUT IMPEDANCE: a) MIC: lOkfl (600SPvl0kQ)
b) LINE:50kO
OUTPUT LOAD IMPEDANCE: a) LINE: approx. 0.3V/10kO
b) HEADPHONE: 0.3mW/8fi
0.775 V/10kS2
EQUALIZATION:
15ips •• NAB 50psec. 3180psec.
7-l/2ips •• NAB 50psec. 3180psec.
INPUT LEVEL:
OUTPUT LEVEL:
BIAS FREQUENCY.:
a) MIC: -70dB±!dB (0.25mV) min.
b) LINE: -8dB (308m V) -18dB SdB (97mV) min.
c) DIN: -38dB ±2dB min.
a) OUTPUT: -8dB, OdB selector
b) HEADPHONE: -24dB±SdB(4.9mV)
c) DIN: -8dB
100kHz (±5kHz; Push-pull oscillator)
CHANNEL SEPARATION:
45dB or more, channel to channel at 1kHz
ERASE EFFICIENCY: 65dB or more
A-6300
FREQUENCY RESPONSE: Overall from recording INPUT to playback OUTPUT
7-l/2ips ••• 40Hz't24kHz ±3dB
3-3/4ips ••• 40Hz , vl6kHz ±3dB
(Measured at 20 dB below the Specified Level)
INPUT IMPEDANCE: a) MIC: 10kQ (600S2vL0kSO
b) LINE:50kS2
OUTPUT LOAD IMPEDANCE: a) LINE: approx. 0.3V/10kR
b) HEADPHONE: 0.3mW/8fl
EQUALIZATION: 7-l/2ips •• NAB 50psec. 3180psec.
3-3/4ips •• NAB 90psec. 3180psec.
INPUT LEVEL:
OUTPUT LEVEL:
a) MIC: -7OdB SdB (0.25mV) min.
b) LINE: -8dB (308mV) -18dB SdB (97mV) min.
c) DIN: -38dB ±2dB min.
a) OUTPUT: -8dB -2dB±$dB(610mV) max.
b) HEADPHONE: -24dB±SdB(4.9mV)
c) DIN: -8dB -2dB±IdB max.
BIAS FREQUENCY.:
CROSSTALK REJECTION:
CHANNEL SEPARATION:
ERASE EFFICIENCY:
100kHz (±5kHz; Push-pull oscillator)
45dB or more, adjacent track at 125 Hz
50dB or more, channel to channel at 1kHz
68dB or more
- NOTE -
Value of "dB" in the test refer to 0 dB=0.775V, except where
specified. -If a Test Set or an AC VTVM calibrated to 0 dB =
IV is to be used, appropriate compensation should be made.
Refer to the TEAC DECIBEL TABLE on page 45 to obtain conversion
of millivolts to dB should your meter not have a dB scale.
- 2 -

2-2. SPECIFICATIONS
MECHANICAL A-61QO
TYPE:
HEADS:
REEL SIZE:
a) 2 track 2 channel stereophonic
b) 2 track 2 channel monophonic
c) 2 track 1 channel monophonic
Erase head x 1, Record head x 1, 2-T Playback x l
4-T Playback x 1
10-1/2" maximum NAB reel
TAPE SPEED:
15ips (38cm/s), 7-l/2ips (19cm/s)
MOTORS:
WOW AND FLUTTER:
6-pole eddy current motors for reel drive x 2
4/8 pole hysteresis synchronous motor
for capstan drive x l
0.15% at 15ips (RMS)
0.18% at 7-l/2ips (RMS)
Wow and flutter measured according to unweighted
(RMS) NAB standard using TEAC YTT-2004/2003 flutter
free tape. Above value is measured during play¬
back.
FAST WINDING TIME: Approx. 140 seconds or less with 1800 ft tape
OPERATING POSITION: Horizontal or vertical
POWER REQUIREMENT: DM : 100V/50Hz, 60Hz
EX : 100, 117, 220, 240V/50Hz, 60Hz
TCA: 117V/60Hz
* TCA models for TEAC CORPORATION OF AMERICA
POWER CONSUMPTION: DM: 90W, EX: 122W, TCA: 122W
WEIGHT:
22 Kg net
MECHANICAL A-6300
TYPE:
HEADS:
REEL SIZE:
a) 4 track 2 channel stereophonic
b) 4 track 2 channel monophonic
c) 4 track 1 channel monophonic
Erase head x 1, Record head x 1 , Playback head x 2
10-1/2" maximum NAB reel
TAPE SPEED:
7-l/2ips (19cm/s), 3-3/4ips (9.5cm/s)
MOTORS: 6-pole eddy current motors for reel drive x 2
4/8 pole hysteresis synchronous capstan motor x 1
WOW AND FLUTTER: 0.18% at 7-l/2ips (RMS)
0.20% at 3-3/4ips (RMS)
Wow and flutter measured according to unweighted
(RMS) NAB standard using TEAC YTT-2002/2003 flutter
free tape. Above value is measured during play¬
back.
FAST WINDING TIME: Approx. 160 seconds or less with 1800 ft tape
OPERATING POSITION: Horizontal or vertical
POWER REQUIREMENT:
POWER CONSUMPTION:
WEIGHT:
DM : 100V/50HZ, 60Hz
EX : 100, 117, 220, 240V/50HZ, 60Hz
TCA: 117V/60HZ
* TCA models for TEAC CORPORATION OF AMERICA
DM: 101W, EX: 135W, TCA: 135W
22 kg net
- 1 -- NOTE -----
As a result of continuing changes and improvements during the pro¬
duction run, minor difference may be found between early and later
machines.
Refer to TEAC TECHNICAL INFORMATION sheet for information concerning
modifications.
- 3 -

3. TOOLS FOR TESTING AND MAINTENANCE
A minimum of the following tools and test instruments are required
for measuring and adjusting to obtain optimum performance.
Regular maintenance tools will be adequate for those not listed
here. If any test instrument listed here is not available, a close
equivalent can be used.
SPRING SCALE . 0^4 kg (CK8 lbs), 0V300 g (O'VLO ozs)
FLUTTER METER . Meguro Denpa Co., Model MK665B (preferred)
or Sentinal Co., Model FL-3D-1.
DIGITAL COUNTER . Range - 0 Hz^lOO kHz
BANDPASS FILTER.TEAC Model M-206A (1 kHz)
VTVM. Hewlett-Packard Co., Model 4302B
OSCILLOSCOPE . . General purpose
BLANK TAPE . TEAC YTT-8013 and YTT-8003
TEAC TEST TAPE. Refer to the next page
EMPTY REEL . TEAC RE-702 (2" hub) and RE-701 (4" hub)
RE-1002 10-1/2" reel
TEAC TEST SET*.M-826A
* Use of the TEAC M-826A Test Set is recommended. This set incorporates
an AC VTVM, Audio Oscillator, Channel Selecting switch. Variable Atte¬
nuator, Monitor Speaker and Cables.
TEAC M-826A measures the EMS value of the Voltage (0 dB = 0.775V).
Characteristics of this Test Set are similar to the standard VU-meter.
Fig. 3-3 Spring Scale
-4

4. TEAC TEST TAPE -VTT SERIES -
- PLAYBACK ONLY -
TEAC-YTT Series Test Tapes are designed for aligning and checking
the playback system performance of any tape recorder. They have
been manufactured to be within close tolerance to the NAB Stand¬
ard, and the recorded signal format has been arranged for maximum
convenience during test procedures.
YTT-l002/1003/1004 (FOR PLAYBACK ALIGNMENT)
TYPE
YTT-l 002
YTT-l 003
YTT-l 004 REMARKS
TITLE
PLAYBACK ALIGNMENT
TAPE
WIDTH
1/4 INCH
BASE
1 MIL
1 MIL
1-1/2 MIL
TAPE SPEED(ips)
3-3/4
7-1/2
15
Accuracy: 0.2%
Wow and Flutter: 0.1%(WRMS)
RECORD TRACK FULL TRACK
Azimuth Angle Tolerance:
90°±1.5 *
RECORDING
STANDARD
NAB
CHARACTER¬
ISTICS
TIME
CONSTANT
(vs)
3180+90
3180+50 3180+50
TOLER¬
ANCE
WITHIN
0.5dB
31.5-4KHz
31.5-lOKHz
31.5-16KHz
WITHIN
1 dB
8K-14KHZ 12.5KHz-20KHz
18K-22KHZ
SECTION
FREQUENCY (Hz)
USE
YTT-l002
YTT-l003
YTT-l004
1
400
400 400
* OdB 30s
Operating Reference
Level Calibration
2
7,500
15,000
15,000
-lOdB
60s
Azimuth Alignment
400
400
400
RECORDED
SIGNAL
3
14,000
12,000
10,000
8,000
6,300
4,000
2,000
1,000
500
250
125
80
63
40
31.5
20,000
18,000
16,000
12,000
10,000
6,000
4,000
2,000
1,000
500
250
125
80
63
40
31.5
22,000
20,000
18,000
16.000
12,500
10,000
6.300
4,000
2,000
1,000
500
250
125
80
63
40
31.5
15s
each
Frequency Response
Check
* OdB recording level is 6dB below the 3% T.H.D. level
YTT-2002/2003/2004 (FOR TAPE SPEED AND WOW-FLUTTER TESTING)
TYPE YTT-2002 YTT-2003
YTT-2004
REMARKS
TITLE
TAPE SPEED AND FLUTTER TSET
TAPE
WIDTH
1/4 INCH
BASE
1 MIL
1 MIL
1-1/2 MIL
TAPE SPEED(ips) 3-3/4
7-1/2
15
WOW AND FLUTTER
' 0.07% 0.05% 0.03%
Weighted RMS
RECORDED WIDTH
FULL TRACK
RECORDED
SIGNAL
FREQUENCY
3,000Hz
LEVEL
-5dB
OdB: Operating
Reference Level
TIME
7 MINUTES
Since these tapes will be your own reference standard, care should
be exercised, in handling and storage, not to expose them to any
magnetic flux which might deteriorate or completely destroy the
recorded signals. High temperature and humidity are also harmful
to the tape.
- 5 -

5. TAPE TRANSPORT PARTS LOCATION
Right-
Reel Motor
Brake Solenoid —
Capstan Solenoid
Flywheel -
Control —
PC.Board
Fuse Holder
Left Reel Motor
— Brake Solenoid
(
-Cl 6
— Freq. Selector
SW 50Hz^60Hz
Fig. 5-1 Tape Transport Parts Location
NOTE
For ordering parts, refer to the exploded view of the
PARTS LIST. An accompanying listing provides the correct
part numbers.
- 6 -

Fig. 6-1 Rear Panel and Bottom Plate Fig. 6-2 Wood Sides
Most amplifier checks and adjustments can be made from the bottom
with the plate removed.
These adjustments should be performed by experienced technicians,
and then only when going through the complete test and check pro¬
cedures on the unit which is being tested.
HEAD ASSEMBLY REPLACEMENT - -
To change the head assembly as a unit, remove the 4 mounting
screws. Note the positions of the wires on the circuit board
before unsoldering. Solder wires of the new assembly in ex¬
actly the same positions. Refer to Fig. 8-3 Head Wiring Section.
Fig. 6-3 Head Assy Removal

REMOVAL OF CAPSTAN MOTOR
1. Remove the 3 screws holding the
capstan motor.
2. Unsolder the 6 wires connecting
the capstan motor.
3. Remove the 4 screws holding the
capstan motor. Watch for the
Rubber Cushions.
4. Loosen the 2 set screws (hex
head) in pulley and lift off
pulley.
- NOTE -
Clean the drive belt with TZ-261B
and the motor pulley and capstan
flywheel with TZ-261A.
Be sure to note the color code of the
wires so you can replace them correctly.
Fig. 6-4 Capstan Motor Removal
REMOVAL OF CAPSTAN ASSEMBLY -
1. Unscrew capstan cover (front
panel).
2. Remove 2 screws from rear bracket,
allow bracket to drop toward floor
of case.
3. Remove capstan belt.
4. Loosen 2 screws in capstan ass'y
flywheel. Remove flywheel.
5. Remove 3 screws in capstan ass'y.
6. Gently move capstan ass'y up and
down until it slides out of panel.
Fig. 6-5 Capstan Assy Removal
- 8 -

REMOVAL OF REEL MOTOR ASSEMBLY
1. Disconnect the 4 motor wires from
terminals and release wire harness
straps.
2. Loosen 2 set screws (hex head) in
Brake drum (A) and 2 in the Reel
Turntable assembly (F). Lift off
these parts.
3. Remove 4 screws securing the Brake
Assembly (D) to the motor. Carefully
lift off the Brake Retainer (B) with
its 2 wires still connected to the
Brake Solenoid (C).
4. Remove 4 screws securing Reel Motor (E)
to chassis through the front panel.
NOTE
Reel motor assemblies are mirror
images of each other; these as¬
semblies are not interchangeable.
Fig. 6-6 Reel Motor Replacement Step 1. Fig. 6-7 Reel Motor Assy Disassembly

REMOVAL OF TENSION ARMS LEFT AND RIGHT
See illustration for complete disassembly instructions.
CAUTION
Do not over-tighten screws
holding right tension arm.
Insulating spacer and
micro-switch are easily
broken by excess pressure.
IMPORTANT
After reassembly check
clearance to ascertain
that arm moves freely
and is not binding.
Fig. 6-8 Tension Arms Removal
HEAD REPLACEMENT
To replace a single head, a nut driver
is required. Remove the 2 nuts on the
defective head through the access hole
provided, this releases the head from
the mounting plate. Rewire the new heads
as shown in Fig. 8-3.
Replace the nuts securing the new head
to the plate. Perform head alignment
before operation.
Shield(A)
3D
T-308
Fig, 6-9 Head Replacement
- 1 0 -

7. LINE VOLTAGE AND FREQUENCY CONVERSION
Unit must be set to the power line frequency available. Improper
frequency setting will result in a 20% error between the tape speed
and reel motors torque. Remove power plug before making voltage conv.
.... NOTE
If it should be necessary to convert the A-6100/A-6300 deck to operate
from a power source of different voltage or frequency, it may be easily
accomplished as follows:
US (TCA) model is preset to 117V AC and 60 Hz. No frequency conver¬
sion is required.
VOLTAGE CONVERSION:
The A-6100/A-6300 (EX) model may be set
for 100,117,220,or 240 volts.
To change the voltage, unscrew the
fuse in the center of the voltage
selector plug. Pull out the plug and
reinsert it so the desired voltage shows
in the cut-out. Reinstall the fuse.
FREQUENCY CONVERSION:
1. Disconnect the power cord and all connecting cables.
2. Take off tape deck rear cover by removing the 6 screws holding
it. The right side-panel may also be removed for your conve¬
nience.
3. To convert the unit from 50 to 60 Hz operation reposition the
capstan belt as shown in the illustration below.
4. The frequency selector switch on the PC Board to the right of
the capstan motor must be switched to the frequency of the power
line.
5. Reinstall rear cover and side panel.
Fig. 7-2 Frequency Conversion
- 1 1 -

8. HEAD ALIGNMENT
HEAD ASSEMBLY (head cluster) is adjusted to very close
tolerance at the factory and normally requires only
minor alignments or adjustments after replacement on
the deck. Complete readjustment of the HEAD ASSEMBLY
will be necessary when an individual head is replaced.
HEIGHT ADJUSTMENT (4 track) -
RECORD HEAD: The record head pole should be above the edge of a threaded
tape by the width of a thin pencil line.
PLAYBACK HEAD: The forward playback head pole should be even with the top
(FORWARD) of a threaded tape.
PLAYBACK HEAD: The pole of the reverse head should be even with the bottom
(REVERSE) of a threaded tape.
ERASE HEAD: Erase section should be a heavy pencil line above.
NOTE
A-6100 2 track RECORD and ERASE heads are centered on the tape.
PLAYBACK head forward section is a heavy pencil line above the edge.
Refer to the illustration below.
Fig. 8-1 Head Configuration and Alignment
- 1 2 -

MIS-ALIGNMENT OF THE HEADS -EXAMPLES-
* ALIGNMENT - The physical positioning of a tape head relative to
the tape itself. Alignment in all respects must conform to rigid
requirements in order for a unit to function properly.
* AZIMUTH - The angle of a tape head pole-piece gap relative to the
direction of tape travel.
NOTE: In order for a tape unit to work at its best, with its own
tapes as well as ones made on other units, its play and record
heads must be aligned to correct the 4 possible errors as illust¬
rated below.
T-330
Fig. 8-2 Head Mis-Alignment -Examples-
HEAD WIRING
A-61QO
A-6300
Fig. 8-3 Head Wiring
- 1 3 -

9. MEASUREMENT AND ADJUSTMENT
-MECHAMIC AL¬
T’he TEAC A-6100/A-6300 uses a highly reliable 3 motor drive system
and should require a min imum of mechanical maintenance or adjustment.
These adjustments are made at the factory. Readjustment should only
be required after long periods of operation or component replacement.
PINCH ROLLER PRESSURE -
NOTE: Pinch roller pressure is supplied by the pinch roller
spring arm and it is most important that the solenoid plunger
he fully bottomed before taking pressure measurement.
1. Load tape or block the shut-off arm in the "ON" position.
2. Attach a suitable spring scale to the pinch roller shaft.
3. Place the unit in the PLAY mode ( ► ), and holding the spring
scale as illustrated, slowly draw it away from the pinch roller.
4. Do not allow the string to rub against the pinch roller.
5. Note the reading on the spring scale at the instant the pinch
roller stops rotating.
6. The scale should indicate 2.2^2.5kg. Optimum value is 2.4kg ±0.1kg.
7. If adjustment is necessary, loosen the 3 screws on the capstan
solenoid and position the solenoid for optimum pressure.
8. Adjust solenoid-limit position so that the gap between capstan
shaft and pinch roller is approximately 7mm when solenoid is not
actuated. Limit is adjusted by loosening the mounting screw (A),
then sliding limit until proper gap is obtained.
IMDT 7
7 'ff///yfJ7jW77T
PINCH ROLLER
SPRING SCALE
CAPSTAN SOLENOID
REPOSITION SOLENOID TO
OBTAIN OPTIMUM PRESSURE
Fig. 9-1 Pressure Measurement and Adjustment Locations
- 1 4 -

BRAKE TORQUE
The brake torque is actuated mechanically. Pressure is set by the
variable spring force. While making these measurements and adjust¬
ments, be careful not to bend the brake bands. As brake torque will
change with cleaning, brake drums and brake shoes should be cleaned
only when absolutely necessary. If cleaning is required, use TEAC
cleaner TZ-261B. After cleaning operate the machine for a month
of normal operation before performing the procedures below.
Brake adjustments are made with _N0 power connected to the equip¬
ment .
1. Place an empty 2" hub reel on the left reel table, and fasten one
end of a 30" length of string to the reel anchor.
2. Wind several turns of string counterclockwise around the hub and
attach a suitable spring scale to the free end of the string.
3. Take a reading only when the reel is in steady motion since the
force required to overcome static friction will produce a false,
excessively high initial reading.
4. The reading should be 1000 g-cm ±200 g-cm.
5.. If adjustment is required, loosen the 2 screws shown and position
the brake for optimum torque.
6. The adjustment of the right brake is the same, with the exception
that rotations are clockwise. (Wind string CLOCKWISE around reel hub.)
NOTE: The difference in reading between the right and left brakes
should be kept within 100 g-cm.
To measure torque when using a reel with a hub radius of other than
5.0cm refer to the following page.
Fi g. 9-2 Torque Measurement and Brake Assy ADJ. Location
- 1 5 -

TORQUE MEASUREMENT PROCEDURE
All Torque and Tension Measurement must be made with the automatic shut- off
switch (right tension arm) blocked to the "ON" position.
BACK TENSION A-6100 ---
1. Place the REEL size switch to the LARGE position.
2. Block the shut-off arm in the "ON" position.
3. Install an empty 7" reel (TEAC RE-702) on the left reel table.
4. Rotate the reel and wind several turns of string counter-clockwise
around the hub. Attfach spring scale to string.
5. Place the unit in the (^) play mode.
6. Pull the scale away from the reel against the motor torque with
a steady smooth motion.
7. Note the scale reading while it is in steady motion.
(The string must not rub the reel flanges.)
8. Adjust R-ll as needed to obtain tension of 300-320 (g-cm).
(calculated value using T = R x W)
9. Repeat all the above for the REEL SMALL position.
Reading should be 180-210 (g-cm) at R-12.
TAKE-UP TORQUE A-6100 -
1. Place the REEL size switch to the LARGE position,
with empty reel and attached spring scale on the right reel table.
2. Place the unit in the ( ) play mode.
3. Allow the rotation of the reel to slowly draw the scale toward
the hub.
4. Hold the spring scale with enough force to allow a steady reading.
5. It should be approx. 780-820 (g-cm).
If adjustment is necessary, slide the band on R-10. (The same resistor
is also used for SMALL REELS).
NOTE
To measure torque when using a reel with a hub radius of other
than 3.0cm refer to following table;
FORMULA FOR TORQUE CALCULATION:
T (g-cm)= R x W
R: radius of hub (cm)
W: gram
For example;
Radius of hub...3.0 (cm)
Scale indication...70 g
Absolute measurement....3.0x70=210 (g-cm)
Use same procedure for the A-6300 using charts on next page
- 16 -

A-6300
Back tension and Takeup torque should be to exact specified Limits
given in the charts below:
If necessary, adjust slider of the resistors until you have
the correct scale reading to get optimum torque.
Refer to ADJUSTMENT LOCATIONS below.
FORWARD PLAY (i
REEL SIZE
TAKEUP
ADJUSTER
BACK TENSION
ADJUSTER
LARGE
SMALL
800-820 (g-cm)
370-410 (g-cm)
R-19A
300-320 (g-cm)
170-210 (g-cm)
R-25B
R-18
REVERSE PLAY (
REEL SIZE
LARGE
SMALL
TAKEUP
880-900 (g-cm)
430-470 (g-cm)
ADJUSTER
R-25A
BACK TENSION
310-330 (g-cm)
200-210 (g-cm)
ADJUSTER
R-19B
R-18
>11
I ... 1. . mIi
[»)

REEL HEIGHT ADJUSTMENT
Reel height Adjustment is required only if a motor has been re¬
placed or if tape rubs excessively against the reel flanges.
Adjustment is accomplished by loosening the reel set screws and moving
the reel table on the motor shaft as shown in the illustration below.
Remove the wooden panel on the right side of the deck for access to
the Set Screws in the reel motor shaft. Reel table should be adjusted
using standard 7" reels. With a tape loaded on the machine, position
the reel table height for smooth tape travel. Be sure to tighten the
Set Screws after adjustment is made.
T-178
Fig. 9-6 Reel Height Adjustment
FLUTTER -
Flutter should be measured in playback mode using a TEAC flutter
free tape YTT-2004 (15ips), YTT-2003 (7-l/2ips), YTT-2002 (3-3/4ips)
and MEGURO model MK-665B flutter meter. Measurement of flutter should
be made in accordance with NAB standards. Values obtained with different
standards or equipment cannot be compared.
Flutter should not exceed: 15ips: 0.15% (RMS)
7-l/2ips: 0.18% (RMS)
3-3/4ips: 0.20% (RMS)
These figures apply to any tape position and direction (such as
full take-up reel, full supply reel or about mid point).
If there is excessive wow and flutter, examine the pinch roller,
belt, motors, capstan shaft, and reel rest for "grease", "oil",
"dirt" and/or "wear". Also examine the tape counter ass'y for
evenness of operation.
TAPE SPEED -
The tape speed should be measured
using TEAC flutter free tape, Model
YTT-2004 (15 ips), YTT-2003 (7-1/2
ips), YTT 2002 (3-3/4 ips). These
tapes contain a highly accurate 3 kHz
tone. Connect a digital frequency
counter to either line OUTPUT jack.
The indicated frequency should be 3 kHz
(± 30 Hz or less) for both speeds.
Fig. 9-7 Test Equipment Set-up
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