Unitron "No-Bee" Rectifier Tube
"No-Bee" was a B-battery eliminator made by the Forest
Electric Company of Newark, NJ, circa 1925. Shown here is the
unique tube that was made for this unit. The output voltage of
this power supply was adjusted by varying the filament voltage applied
to this tube.
The "No-Bee" tube was a full-wave rectifier with two thoriated tungsten filaments connected in parallel, and each plate with a separate connection. The base was brass, and it used a phosphorus getter, which gave it the rainbow appearance. It is not known who actually made this tube, but Newark had a great number of independent tube manufacturers during the 1920's, and this tube could have been made by any one of these companies, or possibly by a major manufacturer like GE.