Maker's Name: 
Radio Corporation of America
Where made: 

The nuvistor was the last of the thermionic receiver valves. The 6DS4 triode is constructed as a series of coaxial tubes. The control grid tube is punctuated with many fine holes, produced by photography and etching. The resultant small structure has very close electrodes, with consequent good high frequency performance, and large current and voltage gain. It withstands high acceleration rates, and was used in aircraft receivers and domestic TV tuners. The 6DS4 has a remote cutoff characteristic, so it would not suddenly cut off and distort when strong signals are applied to the control grid.