Power Amplifying Plate Meter 200 ma, GE Type DW51 Model ADK84
Here is an Power Amplifying Plate Meter (P.A. Plate) as used in military radio installations to adjust the loading and tuning of the transmitter's power amplifier, up to 200 ma. Also displays the PA Grid and Battery status. Measures ~2.5 inches diameter and ~2 inches deep. Believed to be vintage 1940-50's. Serviceability unknown.