GE First Generation Iodine Quartzline Q500T3/CL
In June 1959 GE introduced the world's first halogen lamp for general lighting, of which this is one of the earliest. The year before other types had been developed for infrared heating applications, and for aircraft wing-tip illuminators.

The tungsten-halogen principle involves filling the bulb with a halogenated gas, which reacts with tungsten atoms boiling off the filament surface to form a tungsten halide molecule. This is too volatile to condense on the hot bulb wall, but decomposes to deposit the collected tungsten atoms on the colder filament tails. By this mechanism, bulb blackening is prevented and the bulb can be made much smaller. The smaller bulbs are physically stronger and can be filled with higher inert gas pressures, which in turn reduces tungsten evaporation and allows either the life to be extended, or the filament to be run hotter and hence more efficient for the same life. Hence halogen lamps are generally very much smaller, brighter, and longer-lived than incandescent types.

The first successful halogen lamp was patented when Elmer Fridrich and Emmett Wiley had the idea to dose their infrared lamps with iodine to prevent blackening. The chemistry was then refined by Fred Mosby and Ed Zubler who made the necessary improvements to allow halogen lamps to be commercialised. Mosby is also the inventor of the R7s recessed contact base on this lamp, which replaced the complex terminals of earlier halogen prototypes. Its silver-plated contacts are crimped to a molybdenum wire, which is flattened and etched to a feather-edged elliptical shape to allow sealing through the iodine-filled quartz tube. The ends of the foils are welded to the filament, which is supported axially along the bulb by four tungsten loops.
Manufacturer: General Electric U.S.A.
Lamp Power: 500 Watts
Lamp Voltage: 120 Volts
Lamp Current: 4.17 Amperes
Cap Type: R7s Recessed single contact
Bulb Type: T-9.5 T-3 in eighths/inch
Bulb Finish: Clear GE772 leaded borosilicate
Filament Type: C-8 Axial Single Coil
Atmosphere: Argon Iodine
Luminous Flux: 10,500 lm (initial) 10,400 lm (mean)
Luminous Efficacy: 21.0 lm/W (initial) 20.8 lm/W (mean)
Beam Intensity: N/A
Beam Distribution: N/A
Colour Temperature & CRI: CCT: 3000 Kelvin CRI: Ra 100
Chromaticity Co-ordinates: CCx: 0.452 CCy: 0.409
Rated Lifetime: 2000 hours
Burning Position: Horizontal
Insertion Length: 117.5 mm 45/8 inches
Lighted Length: 76.2 mm 3 inches
Factory: Cuyahoga, Cleveland (OH) U.S.A.
Date of Manufacture: October 1964 Date Code: - 10
Original Value: US $15.25 (1961)
References: 1) GE Large Lamp Price Schedule , Form 2195, 29-Mar-1961, p.15.
2) GE Press Release, Quartzline 500W & 1000W Lamps, 2nd June 1959.
3) GE Press Release, Quartzline Lamps, 18th June 1959.