The position Volt/Cell is essentially designed to monitor the voltage of some accumulators which would be dam-
aged it they were allowed to discharge below a certain value. This value is 1 V /Cell for certain manganese diox-
ide alkaline accumulators.
It is also possible to monitor the external power supply voltage. When in the "BATT. RESERVE" position, if the
indication is that the Nagra is not receiving sufficient voltage, but the Volt/Cell indicates that the power supply
voltage is correct, this means that the Nagra requires an abnormally high voltage. Under these conditions the
Motor and motor collector should be examined.
Measuring the Motor Current
The meter will measure the motor Current when the meter switch is in the position "MOT". There is no corre-
sponding scale on the meter but the "VOLT/CELL" scale can be used.
Full scale deflection corresponds to a motor current of approximately 250 mA. In "NO LOAD" running, i.e. with-
out tape and with the pinchwheel separated from the capstan (but not in the rewind mode), the needle should
indicate between 0.2 and 0.3 V. If this value is exceeded, see chapter 4 pp. 34/35.
External Power Supply
On the right side of the machine there is a 6 pin Tuchel– type T 3403 connector marked "POWER PACK". The
corresponding plug is the T 3400/1.
The connections are as follows :
pin 1 = Battery negative
pin 2 = Chassis (positive)
pin 3 = Pilot playback output
pin 4 = Speed correction signal input
pin 5 = Negative external supply
pin 6 = –10 V stabilized output.
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