The 204A or VT-22 and 38104, is a 250 watt triode with a mu of 23. Maximum frequency for full power is 3 MHz. These tubes replaced the UV204A. The first example is an RCA/DeForest and is also marked with both the RCA and the DeForest number 204A/504A. With this production, the UV prefix was dropped. The second is a later RCA with slightly different construction. The third was made by Sylvania, the fourth by Westinghouse, the fifth by United and the sixth by Amperex. The DeForest company used the 504A number. A similar tube was made in Europe by Philips and designated TB2/250 . These tubes were recommended to be mounted anode down so the markings on the bases and glass are usually upside down as photographed. These tubes were still in production after WWII.
Length = 14.38" Diameter = 3.75"
Max voltage = 2500
Max current = 275 ma
Fil voltage = 11
Fil current = 3.85 amps