Audion triode
Date: circa 1908
Inventory Number: VT1213
Classification: Vacuum Tube
Subject:
Attributed to: De Forest Radio Telephone & Telegraph Company (fl. 1907 - 1931)
Cultural Region:
Place of Origin:
Dimensions:
6.3 x 5.1 cm (2 1/2 x 2 in.)
Description:
A bulb-shaped glass vessel with several electrodes inside. Coming from one end of the tube are two identical thin filaments that make a bend around the center of the tube and go back out. Coming from the other end of the tube is a metallic plate held in front of the filament bends, and a thicker metallic wire that makes several bends between the first plate and the thin filaments.
The filament side has a standard lightbulb screw and the plate side has cables coming out of it: one bright red and one bright green.
The filament side has a standard lightbulb screw and the plate side has cables coming out of it: one bright red and one bright green.
Signedunsigned
FunctionThis is one of the earliest amplifier vacuum tubes or triodes by Lee De Forest. It consists of a cathode of thin filaments, a plate that acts as an anode, and a curved wire between them that was called the grid. For some time it remained unclear how exactly the device worked, but the fact was that it enhanced the detection of radio signals. It was shown later that it worked by amplifying the radio signal detected by the circuit: If one connects the cathode and anode to a voltage source, a current is established, maintained by the electrons produced at the cathode that fly towards the anode. When one connects the grid to a negative voltage, it will prevent some of the electrons from reaching the anode, thereby reducing the current. That way one can modify the current by small changes in the grid voltage. If the grid is attached to an antenna, the effect is to amplify the small signal it receives.
Curatorial RemarksAlmost identical to VT1212 except this one has no sticker.