RCA UX-112 Tube (Early Version)
the UX-112 tube in 1925. Developed by Westinghouse, it was
intended for use as an audio output tube in battery-powered radios as a companion
for the low-power UX-201A. The UX-112 was superseded in 1927 by
the UX-112A, which had a reduced filament power requirement.
The tube shown here is a very rare early example of the UX-112, probably from the first production run. It is interesting for several reasons. Most obvious is the plate which had the RCA logo embossed on both sides. The base is clearly of the UX type, but it was marked as a UV-112. A paper sticker was glued to the bulb to correct what appears to have been a production error. The changeover from the Bakelite-based UV-201A to the UX-201A occurred at about the same as the introduction of the UX-112. This design change may have resulted in confusion which led to this unusual variation.
This may have been a promotional item distributed to dealers or displayed at trade shows. Examples of UX-201A tubes with this type of plate have surfaced.
To the best of my knowledge, the only other manufacturer that embossed their logo into their tube's plates was Raytheon.