Back from the dead? Philips TLD50W/84HF Electronic 5'
This one came to me in original sleeve and certainly looked new, but someone had written 'faulty' on it. Powered it up and sure enough, no worky. The cathodes were in tact and emitting fine (glowing white), but it refused to strike on HF gear that it's supposedly designed for. Anyway I left it on switch start with a glow bottle starter trying to start for about 5 minutes and eventually it struck but the majority of the tube was just a dull pink glow with the ends glowing bright white. After 15 minutes or so it'd come good and has been fine ever since.

Is this what you mean when you say a tube's contaminated? What causes this and is this tube toast or will it be ok now?
Keywords: Philips;Electronic;TLD50W/84HF

Back from the dead? Philips TLD50W/84HF Electronic 5'

This one came to me in original sleeve and certainly looked new, but someone had written 'faulty' on it. Powered it up and sure enough, no worky. The cathodes were in tact and emitting fine (glowing white), but it refused to strike on HF gear that it's supposedly designed for. Anyway I left it on switch start with a glow bottle starter trying to start for about 5 minutes and eventually it struck but the majority of the tube was just a dull pink glow with the ends glowing bright white. After 15 minutes or so it'd come good and has been fine ever since.

Is this what you mean when you say a tube's contaminated? What causes this and is this tube toast or will it be ok now?

tmp_24478-PHOTO_20170725_151144-11616297682.jpg tmp_26025-IMG_9540_JPG743162503.jpeg tmp_26025-IMG_98351297726189.JPG tmp_27140-IMG_20170919_210839-735145161.jpg tmp_27140-IMG_20170920_002309-754821265.jpg
File information
Filename:tmp_26025-IMG_98351297726189.JPG
Album name:fluorescent / Fluorescent Tubes
Keywords:Philips / Electronic / TLD50W/84HF
Manufacturer:Philips
Type/Model:TLD50W/84HF
Wattage:50
Date manufactured:April 1989
Filesize:2706 KiB
Date added:17 Feb, 2017
Dimensions:4302 x 2048 pixels
Displayed:27 times
URL:http://80.229.24.59:9232/gallery/displayimage.php?pid=5325
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eclipsislamps   [17 Feb, 2017 at 08:50 AM]
Yep thats contamination. Normally though its air that is released from the glass due to it not being heated enough when it was being evacuated in the factory, but more often than not it will react with the hot tungsten electrodes, cleaning the gas up but this often produces brown tungsten oxides and nitrides which can coat the glass, making big blotches in particularly bad tubes.
fluorescent   [18 Feb, 2017 at 03:42 PM]
@eclipsislamps, many thanks for the info. If there's any blotching on this one I can't see it so it appears I've been lucky!
eclipsislamps   [19 Feb, 2017 at 12:05 PM]
Must have been a mild case fortunately

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