General Radio Variac Type V10 Variable Autotransformer, National Research Council Provenance
A General Radio Company Variac, Type V10, made in Cambridge, Massachusetts. General Radio introduced the variable autotransformer and trademarked the Variac name. These units became the standard bench instrument in laboratories, broadcast stations and radio workshops for decades. This example comes from Canada's National Research Council. It still has its original N.R.C. property tag, inventory number CRR 10167, along with its CSA approval label (No. 5081). It is a laboratory instrument with a documented institutional history, and that kind of provenance rarely survives on bench equipment. Specifications Manufacturer: General Radio Company, Cambridge, Mass., U.S.A. Model: Variac Type V10 Input: 115 V, 50–60 Hz Rated current: 10 A Output: continuously variable, 0–130 V Front-panel toggle switch and panel-mount fuse holder Original rubber-jacketed line cord and plug CSA Approval No. 5081 N.R.C. Property tag CRR 10167 Use Variacs remain essential to anyone restoring vintage valve radios, tube amplifiers and antique electronics. Bringing old equipment up to line voltage slowly lets aged capacitors re-form, so a first power-up isn't destructive. They are also used for motor speed control, heating elements and general bench testing. Condition Honest working-life wear consistent with decades of laboratory service. There are chips and scuffs to the black enamel, mainly around the rim and dial edge. The white dial graduations and markings remain fully legible, and the knob is intact. [Tested and operating smoothly through its full range / Untested, sold as found.] The unit retains its original two-prong plug. We recommend that buyers who intend regular use have a qualified person fit a grounded three-prong cord. Weight: [__ lb / __ kg]