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Osram-GEC 280W Dual Arc Tube SOI/H Lamp (lit) Now here's a rarity..! The only known fully working example of an already rare lamp, this [url=https://trad-lighting.net/gallery/displayimage.php?pid=380][b]280W dual arc tube lamp[/b][/url] was introduced in 1959 to allow higher light output from an existing 140W lantern. Alternatively, one arc tube only could be lit for lower output after a certain pre-determined time, or to gain longer life between lamp changes. Unfortunately, due to several factors, such as fragility and the need for two ballasts plus a change of lampholder in the fixture, it did not prove popular and was discontinued in 1969. The images above are (left) just after ignition, (centre) after a few minutes running up, and (right) at full brightness. Keywords: Lamps

Osram-GEC 280W Dual Arc Tube SOI/H Lamp (lit)


Now here's a rarity..! The only known fully working example of an already rare lamp, this 280W dual arc tube lamp was introduced in 1959 to allow higher light output from an existing 140W lantern. Alternatively, one arc tube only could be lit for lower output after a certain pre-determined time, or to gain longer life between lamp changes.

Unfortunately, due to several factors, such as fragility and the need for two ballasts plus a change of lampholder in the fixture, it did not prove popular and was discontinued in 1969.

The images above are (left) just after ignition, (centre) after a few minutes running up, and (right) at full brightness.

A20230913_210318.jpg 20240621_102336.jpg GEC_280W_Dual_Arc_Tube_SOI-H_Lamp_Lit.jpg Philips_S-HPV_20W_28Kr-O229.jpg _DSC2301.jpg
Lamp/Fixture Information
Manufacturer:The General Electric Company of England
Model Reference:280W SOI/H
Lamp
Lamp Type:Low Pressure Sodium
Filament/Radiator Type:Dual U-shaped arc tubes
Base:UX4 (British 4-pin valve)
Shape/Finish:T65, clear
Service Life:6,000 hours
Burning Position:Horizontal +/- 20°
Electrical
Wattage:280 (2 x 140W)
Voltage:2 x 160V (2x 450V ignition)
Current:2 x 0.9A (2 x 0.81A starting current)
Optical
Lumen Output:19,000 lm (@ 100h) / 16,800 lm (average)
Lumen Efficacy:67.9 lm/W (@ 100h) / 60 lm/W (average)
Colour Temperature:1700K
Colour Rendering Index:Ra -44
Physical/Production
Dimensions:20¾ in (519 ±10 mm)
Factory Location:Shaw, Oldham
Fabrication Date:March 1959 (Date code QC)
Application/Use:Street lighting
File information
Filename:GEC_280W_Dual_Arc_Tube_SOI-H_Lamp_Lit.jpg
Album name:Ria / Low Pressure Sodium Lamps
Keywords:Lamps
Filesize:333 KiB
Date added:Jul 19, 2024
Dimensions:2330 x 1698 pixels
Displayed:40 times
URL:https://trad-lighting.net/gallery/displayimage.php?pid=24
Favorites:Add to Favorites

Comment 1 to 3 of 3
Page: 1

Max   [Jul 19, 2024 at 12:40 PM]
Really nice! We certainly don't see that everyday.
Sammi   [Jul 19, 2024 at 01:00 PM]
It most certainly is Max, and we're going to get a display case made for it. Cool
Ria   [Aug 19, 2024 at 10:15 PM]
I believe this is the first picture of one of these lamps fully lit to appear on the web, or at least it was when it was on another site we all know and love LPS LPS

Comment 1 to 3 of 3
Page: 1