by Norm Wilson N6JV – Visit the museum at N6JV.com
WD-24
Westinghouse was one of the first American companies to commercially produce vacuum tubes. RCA held the triode patent so Westinghouse and General Electric made tubes for distribution by RCA. These companies also developed experimental tubes for their own use and to develop new products and perfect construction techniques. The featured transmitting triode was found at a swap meet. I don’t think I paid much as nobody knew what it was other than an early, primitive triode that was probably made about 1920. Eventually I identified it as a Westinghouse WD-24, but I have no reference source to prove it. All tube collectors have a library of reference material and I think someone knew what it was and supplied the operating voltages and currents. The plate could be run as high as 2000 volts at 250 ma. The filament was 10 volts at 15 amps. The tube stands 12 inches tall. Westinghouse tubes had several prefix codes and often WD was used to indicate a developmental tube.
This tube was made by spot welding rods to support the plate and grid. The ends were connected to internal metal clamps. In operation, the tube was mounted with straps. This system is similar to what de Forest tubes of this period used. The feature that doesn’t make any sense is the square box shaped plate. Making the spacing between the grid and plate uniform, minimizes the creation of hot spots The variable grid to plate spacing may result in an odd-looking set of performance curves. This design didn’t catch on but it is an interesting example of early experimentation.