TEST OF THE PLATE CURRENTS OF THE POWER AMPLIFIER.
(See Section 169.) |
MeterDesignation
| Reading | Multiplying
Factor | Scale
Reading | Actual
Reading |
IP FRONT
TUBES | Plate current of
front row of tubes | 1 | 325 | 325
Milliamperes |
IP BACK
TUBES | Plate current of
back row of tubes | 1 | 325 | 325
Milliamperes |
| TESTS OF PLATE CURRENTS AND GRID VOLTAGE OF THE VOLATAGE AMPLIFIER |
Jack
Designation | Reading | Multiplying
Factor | Scale
Reading | Actual
Voltage |
| IP1X1 | Plate current of
Tube No. 1 | 1 | 3.3 to 4.5 | 3.3 to 4.5
Milliamperes |
| IP2X1 | Plate current of
Tube No. 2 | 1 | 0.3 to 0.95 | 0.3 to 0.95
Milliamperes |
| IP3X5 | Plate current of
Tube No. 3 | 5 | 2.5 to 5.0 | 12.5 to 25
Milliamperes |
| EC12X1 | Grid bias of
Tubes 1 and 2 | 1 | 9 to 9.5 | 9 to 9.5
volts |
| EC3X5 | Grid bias of
Tube No. 3 | 5 | 6 to 6.4 | 30 to 32
volts |
When running sound-on-film the exciter lamp current should be checked. The reading to be obtained
depends upon the type of exciter lamp used. One type is rated at 7½ amperes and the other at 5
amperes. Adjust the filament current to slightly less than the rating of the lamps used.
| TESTS OF EXITER LAMP CURRENT. |
Jack
Designation | Reading | Multiplying
Factor | Scale
Reading | Actual
Voltage |
| ILBX1 | Plate current of
Tube No. 1 | 1 | 5 or 7.5 | 5 or 7.5
amperes |
| ILAX1 | Plate current of
Tube No. 2 | 1 | 5 or 7.5 | 5 or 7.5
amperes |
8
