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Gas Discharge Tubes

This section includes Geissler tubes and their immediate descendants, including spectrum tubes, flash tubes and laser tubes.

Aerolux Bluebird Bulb

In a time before television, decorative electrical lamps were considered a legitimate form of entertainment. Such devices were birthed in the 19th century, in the form of fashionably scientific Crookes tubes, as well as more novel Geissler tubes and other 'gas sculpture' type lamps. By the early 20th century, the decorative lamp had evolved into mass-produced Aerolux bulbs, gas discharge lamps with decorative brass electrodes which could be driven with common AC line power. Aerolux lamps are usually filled with neon or argon, and often contain phosphor-coated elements to produce a multicolor display. The lamp pictured here is an Aerolux Bluebird Bulb, constructed from multiple decorative jewelry findings which were manufactured by Guyot Brothers Company Inc. The bulb's argon fill produces a purple glow, while the green illumination is produced by a phosphor coating. [View Detail]

Argon Laser Tubes (Unknown Mfr.)

Argon laser tubes operate like any other ion laser, producing a multi-wavelength blue beam. The argon laser beam consists of ten wavelengths: 351 nm, 454.6 nm, 457.9 nm, 465.8 nm, 476.5 nm, 488.0 nm, 496.5 nm, 501.7 nm, 514.5 nm and 528.7 nm. The unidentified argon laser tubes pictured here are fairly typical in construction, with a cermet envelope composed of beryllia ceramic and copper. [View Detail]

'Globe' Spectrum Tubes (Unknown Mfr.)

Devices included in this entry: Argon spectrum tube (glass capillary vessel) Krypton spectrum tube (glass capillary vessel, pictured in thumbnail) Another example of a set of spectrum tubes with unusually shaped envelopes. These tubes have right angle electrodes like the "H" shaped tube above, but add the extra attachment of a globe shaped discharge chamber at one end of the capillary vessel. We are not sure why someone would construct a spectrum tube like this, though it does produce a much more interesting gas discharge effect than a standard linear spectrum tube. [View Detail]

'H' Spectrum Tube (Unknown Mfr.)
	This spectrum tube, filled with molecular hydrogen, has an unusual H-shaped envelope. Manufacturer is unknown. [View Detail]

Hamamatsu L1788-50 NQ
	The L1788-50 NQ is a Sn (tin) hollow cathode lamp used for spectral research. The L1788-50 NQ radiates deep UV, at a wavelength of 224.61 nm. [View Detail]

Welch Scientific Geissler 'Aurora' Tube

The Geissler tube is an electical demonstration device that was invented in 1857 by Heinrich Geissler. Starting in the 1880s, Geissler tubes were mass-produced as functionally useless decorative devices, designed to provide entertainment to wealthy Victorians who had become bored with their stereophotos and Maltese cross tubes. Technically, a Geissler tube is simply an evacuated glass tube with two electrodes, which has been filled with a noble gas or other substance to produce a demonstrational glow discharge. In practice however, Geissler tubes are usually highly decorated, formed into complex shapes and encrusted with whorls of uranium glass and liquid filled cavities. This particular example is somewhat unusual due to its completely unshaped and undecorated envelope, and might be better referred to as a linear gas discharge tube. Powering such a tube in Victorian times required a special high voltage induction coil, but the modern hobbyist can power one with an easy-to-find backlight inverter. [View Detail]

Melles Griot HeNe Laser Tube (Unknown P/N)

This is an example of an older low power 'hard seal' helium neon laser tube. Unlike early 'soft seal' helium-neon lasers, this tube has its mirrors permanently fused to the glass envelope, which prevents the helium from escaping over time. A hard seal tube can be expected to hold its gas for several decades, as opposed to the one- to three-year lifespan of the average soft seal tube. The exact power output of this unit is unknown, but is probably at or below 1mW. [View Detail]

Crookes Cathode Ray Tube (Unknown Mfr.)

"Crookes Tube" is the generic descriptor given to a wide range of hard vacuum demonstration devices, each with a different educational function. This particular tube, also known as a "beam deflection tube" was designed to illustrate how a cathode ray beam could be deflected by a magnet. A thin beam of cathode rays is projected through the slit at one end of the tube and strikes a slanted metal plate, which has been covered with a phosphor to produce a visible line discharge. When a magnet is brought near the tube, the effect of the magnetic field can be seen in the deflection of the cathode ray beam. Though traditionally cathode ray tubes of this type were pumped down to a vacuum state, the example shown here is a newer gas filled version, most likely made during the 1950s. To make it easier to strike the tube with lower voltage supplies, this example has been filled with hydrogen, which is what produces the blue discharge at either end of the tube. [View Detail]

Siemens LGR-7649
	Laser tube, 1.5 mW, HeNe. [View Detail]

Sylvania 1B59 / R1130B
	The 1B59 is an actinic crater hollow cathode lamp used as a glow modulator in fax machines, halftone scanners and various military imaging devices. The 1B59 has two pins and a standard octal-style base. [View Detail]

Pressler Spectrum Tubes (Unknown P/Ns)

Devices included in this entry: Pressler hydrogen spectrum tube (linear capillary vessel) Pressler helium spectrum tube (linear capillary vessel) Pressler neon spectrum tube (linear capillary vessel; pictured in thumbnail) Pressler mercury spectrum tube (linear capillary vessel) Pressler water vapor spectrum tube (linear capillary vessel) Spectrum tubes are linear Geissler-style tubes with a central capillary section which dramatically increases glow intensity within the capillary. Spectrum tubes are used for various kinds of spectral research, and any respectable high school physics class has a set of them. Spectrum tubes are available in traditional tube gasses, such as neon and mercury vapor, as well as more exotic flavors like 'water vapor' and 'air'. Spectrum tubes are typically mounted in a specially constructed spectrum tube supply, but they also light well with a common 'copper brick' laser supply, or violet ray generator. [View Detail]

Sylvania JAN-CHS-SS-501
	The SS-501 is an argon-filled flash tube, which operates at 1.5 kV and is triggered with an externally wrapped coil. Ludwell Sibley's reference guide Tube Lore refers to the SS-501 as a control tube. The SS-501 produces an intense blue-white discharge at full operating voltage. The example pictured here has an uncommon internal configuration. [View Detail]

Uniphase Laser Tube (Unknown P/N)
	An example of a late era Uniphase helium-neon laser tube. This type of tube was almost exclusively used as a laser projector for early barcode scanners. [View Detail]

Deuteurium Arc Lamp (Unknown Mfr.)

This unusual device is a deteurium arc lamp, a type of laboratory UV light source. This lamp is approximately the size of a standard octal tube, but has only three leads which are covered in thick insulation. There are two rectangular chambers in the center of the lamp, with small slits in the front. There appears to be a large heater coil in the outer chamber, which is open on both ends. The lamp has an argon-like ionization glow. Special thanks to Giorgio Basile for identifying this device.

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