Signedstamped in white on bulb: 30 M.A. / COOLIDGE / (VICTOR logo) / - TUBE - / MADE IN U.S.A. / 72696
Inscribedstamped in white on tube: PATS. JAN. 31, '11 SEPT. 5, '11 FEB. 27, '11 / APR. 2, '12 APR. 16, '12 DEC, 30, '13 JUNE 23, '14 / MAY 18, '15 NOV. 30, '15 OCT. 31, '16 JAN. 2, '17 / JUNE 4, '18 JULY 15, '19 DEC. 23, '19 APR. 12, 21 / JUNE 24, '24 JULY 29, '24 OCT. 20, '25 / PATENTS PENDING / THIS TUBE IS NOT LICESNSED TO BE / RE-EXAUSTED OR REPAIRED NOR / THE METAL THEREIN CONTAINED / LICENSED TO BE USED EXCEPT IN / THIS PARTICULAR TUBE. / GENERAL ELECTRIC X-RAY CORP. / CHICAGO, ILL., U.S.A.
FunctionThis Coolidge tube produces electrons by the heating of a cathode filament. These electrons are accelerated by a high voltage and hit the angled anode to produce the x-rays. Due to the large amounts of generated heat, this unit has radiator fins as a cooling mechanism, which allowed for a relatively small bulb size. It could also work without a rectifier as the anode was kept cold enough not to emit electrons for an inverse current. This one is a diagnostic tube.
ProvenanceFrom the Harvard Medical School.