Signedon inside, center left: MODEL 707 DYNA-JET / DYNAMIC MUTUAL CONDUCTION / TUBE TESTER
Inscribedinside, on bottom: B&k DIVISION OF DYNASCAN CORP. 117 VAC . 60 CPS - MADE IN U.S.A.
Primary SourcesOperating Instructions for Model 707 Dyna-Jet Dynamic Mutual Conductance Tube Tester (Chicago: B & K Division of Dynascan Corporation, 1968). online here.
ProvenanceDepartment of Psychology, Harvard University; transfer to CHSI, c. 1999.