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Philips Historische Producten museum Eindhoven (49/52) The first triode tube produced by Philips for radio applications (signal amplification), among other radio tubes. This device is possibly a prototype of their PH-IDZ tube (which can be seen at the bottom), whose production began in 1918. It is based on Lee de Forest's Audion tube design, which was initially filled with a gas at a very low pressure (the name is a contraction of audio and ion). Investigations on such tubes, and particularly on their light emission, laid the foundation of the company's gas discharge lamp business. Keywords: Miscellaneous

Philips Historische Producten museum Eindhoven (49/52)


The first triode tube produced by Philips for radio applications (signal amplification), among other radio tubes. This device is possibly a prototype of their PH-IDZ tube (which can be seen at the bottom), whose production began in 1918. It is based on Lee de Forest's Audion tube design, which was initially filled with a gas at a very low pressure (the name is a contraction of audio and ion). Investigations on such tubes, and particularly on their light emission, laid the foundation of the company's gas discharge lamp business.
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File information
Filename:_IMG0287.JPG
Album name:Max / Places and displays
Keywords:Miscellaneous
Filesize:1091 KiB
Date added:30 May 2026
Dimensions:1800 x 1200 pixels
Displayed:88 times
DateTime Original:2016:08:23 14:19:08
URL:https://trad-lighting.net/gallery/displayimage.php?pid=1295
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Comment 1 to 6 of 6
Page: 1

Sammi   [Sat 30 May 2026 at 19:08]
Very interesting information. Love
Ria   [Sun 31 May 2026 at 00:24]
As always from our Max Very Happy
Drew   [Sun 31 May 2026 at 01:04]
I love those super old spherical tubes, it is just crazy to me how much manual effort went into these! Is that an E12 base?
Max   [Sun 31 May 2026 at 07:17]
Manual labor was much cheaper back then, Drew. I don't know the exact cap size of this lamp... I would say it's closer to E14.

Ria & Sammi - Thank you ladies, glad you are enjoying this presentation. That museum is a very interesting place and more pictures will come (as you can guess from the counter in the title)
Tuopeek   [Tue 02 Jun 2026 at 17:36]
Been planning to have a go at making a triode for fun just need to get the vacuum pump and glass seals a little better first. Glad to see there's still a museum in Eindhoven, shame its not in the Evoluon.
Max   [Wed 03 Jun 2026 at 06:47]
The Evoluon was sold off to developers in 2018 and the only museum in Eindhoven which is still owned by Philips (i.e., the original company factory from 1891 located at the Emmasingel in the city center) is mostly about marketing stuff. The really interesting place to visit, the Philips Historische Producten museum, is actually run by volunteers (mostly former Philips employees). This shows the difference in management of the company's history between corporate suits and real enthusiasts.

Good idea about the homemade triode! That's something I should try as well, the De Forest's Audion design is quite simple (I need to get my hand on a spot welder though). As for the vacuum issue, one possibility is to seal the tube off with a significant fill pressure enabling a glow discharge between electrodes (preferably the grid and the plate). If the gas fill is of molecular nature (e.g. air), then plasma dissociation and gas clean up will result in a significant pressure reduction that will eventually result in the extinction of the discharge.

Comment 1 to 6 of 6
Page: 1