The VCR138 cathode ray tube is a WW2 classic. The base is 12 side contacts and fits into a special base. The screen is round and has a 3 inch viewing diameter. The phosphor is probably P1 and designed to give a medium persistence green trace.

The operating voltages are arranged to give the final anode at deflection plate potential of, say, 200 Volts. These leaves the cathode at about minus 1000 Volts. The heater cathode insulation is poor and the 4.0V heater at 1 Amp would have to be supplied by a separate transformer winding. The deflection is electrostatic.

Our example is marked with a crown and the letters AM for Air Ministry.

The end window envelope neck is 58 mm in diameter and, including the B12D base pins, is 337 mm tall.

This exhibit was last updated on 03 August 2006