Operating the E381S Receiver:
Instead of reading the desired receiver frequency directly from a dial, the E381S operator used one of two cardboard calibration charts mounted on
the receiver’s flip-open top. The calibration chart for bands 1-5 (in Roman numerals, at the very top of the chart) is shown in this photograph. Bands Roman numerals 6-10 similar, on the second calibration chart.
Photo by Bruce Culp
Photo by permission of www.Horst-Beck-Collection.com