Teac A-3440 - Take-Up Torque; Back Tension

TORQUE MEASUREMENT PROCEDURE
NOTE: The following torque measurements should be
made with a spring scale that is calibrated to read
Torque in gram-cm. for a 7’’ reel with a small reel
hub. If the spring scale you are using is calibrated
to read Force or Weight in grams the Torque must
be calculated using the Formula:
Torque (in gm-cm or 0z:in) =
Weight or Force (in gr. or oz.) x
radius of hub (in cm or inches)
If you are using a reel with other than the standard 2.5” or
6.0 cm (approx.) diameter hub, the Torque must be calcu-
lated using the same formula and substituting the actual
radius and Weight or Force reading.
All Torque and Tension measurements must be made with
the automatic shut-off switch (right tension arm) held in
the ON position.
Brake Torque Measurements should be made using large
hub reel with a hub diameter of 4. or 10.2 cm.
BACK TENSION (FWO)
so rakeuP Torque (Fwo?
i 1.628
Fig. 7-3 Torque Measurement
7-3. TAKE-UP TORQUE
1. Place an empty reel on the right reel table and attach
spring scale.
2, Place the deck in the Play mode.
3. Allow the rotation of the reel to draw the scale slowly
towards the hub.
4. Hold the spring scale with enough force to allow asteady
reading.
5. The reading or calculated value should be approx.:
[ REEL SW| TAKE-UP TORQUE
770 to 830 g-cm (11 to 12 oz-inch)
370 to 410 g-cm (5.2 to 5.7 oz-inch)
NOTE: LARGE size value is for reference only.
7-4 BACK TENSION
1. Place an empty 7” reel with small hub 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 counter-clockwise around
the hub. Attach spring scale to string.
3. Place the deck in the Play mode.
4. Pull the scale away from the reel against the motor tor-
que with a steady, smooth motion.
5. Note the scale reading while it is in steady motion.
(The string must not rub the reel flanges)
6. The reading or calculated value should be approx.:
BACK TENSION
330 to 390 g-cm (4.6 to 5.5 oz-inch)
180 to 220 g-cm (2.5 to 3.1 oz-inch)
NOTE: LARGE size value is for reference only.
Adjustment Location
If necessary, adjust slider of the resistors until you have the
correct scale reading for optimum torque. Refer to adj. loca-
tion below.
for TAKE-UP TORQUE
for BACK TENSION
for F.F (or REW) BACK TENSION
NOTE: No.3 for no adjustment provided (FIXED),
Fig. 7-4 Resistors Adj. Location
7-5 FAST FORWARD AND REWIND TORQUE
SPECIFICATION
2000 g-cm (28 oz-inch), or more at F.F.
2000 g-cm (28 oz-inch), or more at REW
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