The voltage amplifier, mounted on the rear of the panel, differs slightly from those used in the PG-1 equipments and is described in section 136. The two pilot lamps in the upper left-hand corner of the panel labeled "PROJECTOR A" and "PROJECTOR B" indicate which projector is "faded in" to the voltage amplifier. The volume control is at the top of the panel and, like the volume control of the PA-1, it is calibrated from 0 to 40 to give twenty steps of equal volume change. The meter directly below the volume control is a test meter. It is connected by

means of a suitable cord to a jack plug for use, in conjunction with the jacks distributed throughout the rack, in measuring the various currents and voltages. The two rheostat knobs, one on either side of the test meter are used for exciter lamp current control. Directly below each exciter lamp rheostat are exciter lamp switches. In a row along the bottom of the panel are seven jacks. The jack at the extreme left is the phonograph pick-up jack, for use in making an input

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