Experimental Fleming valve in wooden mount. This valve was preserved as a "relic" by Fleming, who sent it to a magazine editor in 1926. A glass tube containing a filament and cylindrical electrode mounted in a wooden stand. Two binding posts are set on top, a third is on a side arm, and a spring maintains tension on the tube. The mount is an experimental piece that can be used to test different tubes of this design.
Marked: "1701". In original box with instruction sheet. A moderate power triode designed for use as an audio frequency amplifier, but can also be used as an RF amplifier or oscillator. Eff = 4.5 volts; Ip = 1.6 amperes. Ep = 200 - 400 volts; Ip = 8 - 40 milliamps. Mu = 6.7 - 7.4; Rp = 3500 - 4800 ohms. Tyne notes that the locking pin on 205 type tubes was set 45o differently from other tubes to prevent low-power tubes from being inadvertently substituted. Reference: Tyne, "Saga of the Vacuum Tube," page 287.
"The No. 205D is a three-element filamentary type tube intended for use as a radio-frequency amplifier, oscillator, modulator, and audio-frequency amplifier in output stages when moderate powers are required." Reference: Western Electric 205D data sheet: https://www.westernelectric.com/s/205D.pdf.
Western Electric type 216A high-vacuum triode amplifier - oscillator. A 4-pin base with tipped G-shaped envelope. Marked: "Western Electric / Made in U.S.A. / 216 A / Pat. in U.S.A. / 1-15-07 2-18-08 10-17-16 12-19-16 12-17-18 6-24-19 1-27-20 6-13-22 / Pats Applied for"; paper label around neck reads: "Licensed for use only as part of the Western Electric Loud Speaking Telephone Outfit." Reference: https://www.westernelectric.com/s/216A.pdf; Tyne, "Saga of the Vacuum tube," pages 291-293.
Paper label reads: "W.R.S. Co. Inc / New York / Date [checked?] April 15, 1935". A vacuum pentode, triple grid power amplifier tube. Plastic base with 7-pins. Glass envelope. Reference: https://www.radiomuseum.org/tubes/tube_59.html
5 watt transmitting triode. A 4-pin plastic base with S-shaped glass envelope, getter stain. Stamped on base: "de Forest / Audion / 510"; inked on stem assembly: "4753 3K23". Reference: https://www.radiomuseum.org/tubes/tube_510.html. Object is on the right in the photo.
Seven pins surrounding an exhaust tip on the bottom. T-shaped envelope with glass seam around the base. Stamped: "826 [twice] / SC961A / Ken-Rad / Made in U.S.A." Reference: https://www.radiomuseum.org/tubes/tube_826.html.
VT-2 tube with envelope. Audion is being used generically here. Brass 4-pin base (gold tips on tines) with bakelite insulator, two plates and grids with one emitter. Stamped on the shell: "Pat. in U.S.A. / 1-15-07 Two patents / 2-18-03 4-27-15 / 12-19-16 / Pat. Applied For". Reference: Tyne, "Saga of the Vacuum Tube" 100-103, 286-287; https://www.radiomuseum.org/tubes/tube_vt2.html.
Marked: "1701". In original box with instruction sheet. A moderate power triode designed for use as an audio frequency amplifier, but can also be used as an RF amplifier or oscillator. Eff = 4.5 volts; Ip = 1.6 amperes. Ep = 200 - 400 volts; Ip = 8 - 40 milliamps. Mu = 6.7 - 7.4; Rp = 3500 - 4800 ohms. Tyne notes that the locking pin on 205 type tubes was set 45o differently from other tubes to prevent low-power tubes from being inadvertently substituted. Reference: Tyne, "Saga of the Vacuum Tube," page 287.
"The No. 205D is a three-element filamentary type tube intended for use as a radio-frequency amplifier, oscillator, modulator, and audio-frequency amplifier in output stages when moderate powers are required." Reference: Western Electric 205D data sheet: https://www.westernelectric.com/s/205D.pdf.