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Picture from the 1904 Catalog |
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14” (35cms) long, 5”(12.5cms) bulb, this tube, of the “light anode” type,
first appeared in the CHF Müller Catalog in 1904.
But this particular tube, bearing No. 74071, was most probably manufactured
early in 1909, the CHF Müller factory having
celebrated its 75000th tube in May of that year. (Willi Stamer,“100 Years of X-Ray Tubes”, p.23, Philips Medical Systems, 1999). The target is a platinum disc
embedded in the nickel anti-cathode and held in place by four small metal
claws. The aluminium cathode is of the typical
concave shape, and the anode is of the rod type. The regeneration is by a
Mica Disc device. Of particular interest, is
the sticker in German on the cathode side of the glass tube wall that reads “Härtegrad 4-5 Walterscale”
(Hardness grade 4-5 on the Walter Scale). This scale was introduced by
Professor Bernhard Walter, based on the size of the spark gap of the induction
coil. |
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“….by setting
the hinged wire at any given distance from the cathode end, the tube will
regulate itself to the vacuum corresponding to that distance, for as the
resistance of the path between the proper electrodes increases, current
passes around by the mica discs down the wire and jumps across to the
negative end, setting free a minute quantity of gas from the mica, and the
vacuum is lowered, allowing the current to pass in the usual way.” ("A Text-Book of Radiology”, E. R. Morton,
1918, p.51) |
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Professor Bernhard Walter worked in
close cooperation with CHF Müller, and as early as
1898 or 1899 had proposed the use of a water-cooled anti-cathode. (Willi Stamer“100
Years of X-RayTubes”, p.16, Philips Medical
Systems, 1999) |
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