A German triode for radio receivers. Plastic base with three banana pins and one tubular pin. Horizontal cylindrical plate with axially mounted grid and filament. Filament rated at 0.5 - .06 amperes at 4 volts. Anode rated at 65 volts, 1 milliampere. Reference: Tyne, "Saga of the Vacuum Tube," pages 251-252.
A "Welsh Peanut Tube". A brass candelabra bayonet base with two contacts, glass insulator, a white-insulated lead emerging from the base shell. The green insulated plate wire is missing from this specimen. Marked: "Welsh". Distributed by Radio Research Guild, made by Welsh Electric Lamp Corp, Reference: Tyne, "Saga of the Vacuum Tube," page 365.
A short glass vacuum tube with flat end, steel skirt, glass insulators, two pins (one .375" long, the other .125") emerge from top. An exhaust tip is set next to the skirt. A metal wire mesh is mounted inside the neck of the tube. No extant maker's marks.
Moorhead laboratories "Electron Relay" or ER tube. A 4-pin base with brass shell, plastic insulator. Dull-sheen anode. Tipped envelope, cork lead insulator, cylindrical collector, spiral grid, single-arch tungsten emitter. Printed on envelope: "Licensed for amateur or / experimental use only. / E.R. 537857"; stamped on base: "De Forest Audion / U. S. Patent No.s. 841387-879532 / Sold only for amateur / and experimental use"; also: "Marconi [globe logo] / Trade Mark / Fleming Pat [??] 8[?]3684". "S" molded on base insulator. Note on file reads: "Manufacture: Moorhead laboratories." Reference: Tyne, "Saga of the Vacuum Tube," page 174-176.
