Gilbert's Rectiformer

In 1947, Gilbert introduced DC locomotives and needed transformers that would provide DC power.  In that year they offered a DC train controller called a Rectiformer.  The cataloged version was numbered 14 and was rated at 150 watts.  An un cataloged 100 watt version was also offered.  Both versions have definitely been dated to 1947 based on dating stamped inside the cases.  The 100 watt unit appears to have been the version included with the 4622 Complete Railroad System set discussed in a previous link in this section, as that is the unit that has been found in the few existing 4622 sets found.  This includes early sets which did not include the 2B 75 watt transformer as well as later sets that did contain the 2B transformer.  This transformer was added most likely because the Rectiformer, especially a smaller 100 watt unit couldn't handle the current demands of all the accessories included in this two train set.  All 1947 units came with the Sylvania X6089 rectifier tube which had a propensity to fail.  In addition the 1947 units were not internally bridged between the AC and DC sides which caused problems with the control of the operating cars and the factory issued instructions to connect the inside post of the AC side to the inside post of the DC side to correct this defect.

 In 1948, Gilbert temporarily abandoned the Rectiformer, most likely because of its serious operational flaw caused by the failure of the tube.  That year they offered the No.15 rectifier to be used with their normal transformers.

The Rectiformer was reintroduced in 1949 with a new No. 1237 tube that worked well.  It is believed that both 100 and 150 watt versions were offered that year and the units included the internal bridging so no external bridge was required.  They were marked with a "B" on the bottom to indicate this had been done.

In 1950 the Rectiformer was renumbered 16 and was rated at 150 watts. I am not aware of nor have any of my sources seen 100 watt No. 16 Rectiformers. My initial research has determined that the 1237 tube was probably used in other applications as it is listed in technical specification history publications and is rated at only 3 amps.  Considering that the fact that a DC locomotive can draw as much a 2 amps that is only marginally sufficient considering the draw of lighting circuits in cars.  If used to control 2 trains, as suggested in catalogs, with one DC train and one universal motor equipped train, also drawing about 2 amps, its capacity could easily be exceeded. While this version worked well, it was barely sufficient.  The X6089 tube used carbon anodes, which is common in higher current applications, so it is possible that Gilbert was aiming initially at providing greater rectified DC power, but the tube just didn't perform as planned. The 1237 appears to be of a more conventional design using nickel plated steel anodes.  Research on this is continuing and will be posted here.

Thanks to Lonny Beno for his assistance in preparing this page.