“BETZ” Tube









             This German made tube is 14”(35cms) long with a 6”(15cms) bulb. It dates probably to the mid-years of the first decade of the 20th Century, and bears on the cathode side of its glass wall the inscription:

                                                   Frank S. Betz  Co., Chicago.

                                                   Germany - No. 2849

                                                   Patent pending.


              The aluminum cathode is of the typical concave shape. The light anti-cathode is fitted with a platinum foil target, and the anode is a small flat aluminum disc.


              The unusual feature of this tube is its 3-electrode regeneration device where the  “anode” electrode, to the left in the picture, is a spiral of thin shiny metal wire, probably platinum, around a small glass rod. The “cathode” electrode to the right is a small flat aluminum disc, 12mm diameter. The third electrode, a flat disc facing the communication between the regeneration device and the main tube cavity, is of the same size as the cathode disc, and is covered with a rough and granular black material, probably of carboniferous nature. The mode of action of this regeneration device is unclear, and any explanation of the process will be appreciated..   

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