AW-1 Audio Wattmeter.

Measure output power levels directly. Flat from 10 Hz to 250 kHz.
Full scale ranges:  5-mw, 50-mw, 500-mw, 5-w and 50-w. Db calibration
from minus 10 db to plus 48db. Non-inductive built-in load resistors with
impedances of 4, 8, 16 and 600-ohms.
Meter bridge uses four germanium diodes.

6 lbs.  
1954:  $29.50.