30 year old Plumbicon video camera tube - likely still working? - Page 1
Forum section: electronics / projects

author: Dave92F1
author_rank: Contributor
timestamp: August 24, 2022, 03:57:55 pm
content: I'm tempted to buy a mid-90s Plumbicon video camera tube on eBay for some experiments.It's listed as "new in box". It's kind of expensive.Is it likely to still be working or do these things age to death just sitting in the box? (I read somewhere that old video camera tubes in general tend to "wear out" with age - maybe due to light exposure; I don't remember the details).

author: Gyro
author_rank: Super Contributor
timestamp: August 24, 2022, 04:47:12 pm
content: Referring to my 1982-83 EEV Porfessional Electron Tubes catalogue, they list Leddicons, which I think may have been the EEV trademark for the similar Philips trademarked Plumbicon (?). Looking at the web, both appear to have used a Lead Oxide photoconductor.The EEV book includes a 'P4217 Leddicon Conditioning Unit', which was aQuoteI don't know how relevant this is, and what the shelf life actually was [Edit: apart from maybe not being 30 years].

author: Dave92F1
author_rank: Contributor
timestamp: August 24, 2022, 07:40:14 pm
content: Thanks. Plumbicons are definitely lead-oxide tubes.That makes me reluctant to spend $350 on a tube that's been sitting on a shelf for 30 (maybe 35) years.Too bad. This is one of very few electrostatically deflected camera tubes. (My goal is to experiment with non-standard raster patterns; I think the usual magnetic deflection coils are tuned for ~30 kHz sweep.) I may have to settle for just simulating it.

author: Gyro
author_rank: Super Contributor
timestamp: August 24, 2022, 08:57:56 pm
content: An electrostatically deflected Plumbicon sounds pretty rate - I thought they all had magnetic deflection yokes. It must be a special purpose medical one (apparently they continued to be used for niche medical applications after broadcast cameras went solid state).$350 does sound like a lot of money for a (probably rather attractive) potential paperweight. I don't know what the dergadation mechanism was, presumably some sort of poisoning or change in diffision in the target resulting in increased leakage, or whether Philips ( later Narragansett Imaging) were able to improve the 'chemistry' in later production.Quotehttps://en.wikipedia.org/wiki/Video_camera_tube

author: Seekonk
author_rank: Super Contributor
timestamp: August 24, 2022, 09:13:15 pm
content: That reminds me of a mentor who was head of biomedical engineering at a teaching college back in the early 70's. He scoured thrift shops for old TV that were electrostatically deflected. He would mix video in with scan signal and get blood vessels appear to jump out of the screen like 3D. Old school method of image processing. The things he built and attached to people would be a feast for malpractice lawyers today. Remember those $2.99 metronomes epoxied in muffin trays in the back of popular mechanics? He kept people alive with them as external pacemakers. Was he worried that they were made with surplus junk. He said the nurses were monitoring them back at their station.

author: james_s
author_rank: Super Contributor
timestamp: August 24, 2022, 09:43:36 pm
content: I don't think I've ever seen an electrostatically deflected TV, other than maybe that Sinclair flat portable, I think it was. Does anyone have other examples?

author: Gyro
author_rank: Super Contributor
timestamp: August 24, 2022, 09:59:00 pm
content: https://www.earlytelevision.org/rgd_382-rg_crt.htmlEdit: Another one, with lots of nice technical detail...http://www.worldphaco.com/uploads/Admiral_TV..pdf

author: Dave92F1
author_rank: Contributor
timestamp: August 25, 2022, 12:18:37 am
content: Quote from: james_s on August 24, 2022, 09:43:36 pmI don't know about TVs, but electrostatically deflected CRTs were quite common on oscilloscopes, and electrostatically deflected CRTs remain easy to find. And they're not difficult to adapt to display TV pictures.Unfortunately the same is not true for camera tubes. The Philips one I'm looking at is a super high resolution one meant for x-ray machines of some sort (monochrome of course). They're asking $400; I was hoping to get it for $350. But if it's DOA from age I'll keep my money.

author: Gyro
author_rank: Super Contributor
timestamp: August 25, 2022, 10:04:26 am
content: Personally, I would explain the shelf life issue and shoot for $200.

author: Wolfram
author_rank: Frequent Contributor
timestamp: August 25, 2022, 10:11:46 am
content: Quote from: Seekonk on August 24, 2022, 09:13:15 pmThis sounds like the sort of video processing done by the Rutt/Etra video synthesizers. There are some very psychedelic examples of this sort of processing on Youtube for the curious.

author: Dave92F1
author_rank: Contributor
timestamp: August 27, 2022, 07:30:30 pm
content: Well you talked me into it, Gyro. I bought the dammed thing for $250 (talked the guy down from $400 on eBay). It's new in a sealed factory box.Naturally, the day after I bought it, I realized I don't know the pinout.Anybody know how to figure it out? It's a Philips XQ5002.

author: Gyro
author_rank: Super Contributor
timestamp: August 27, 2022, 07:49:31 pm
content: Hey, don't blame me!I found a datasheet, it seems to have everything but the pinout though!https://www.datasheetarchive.com/pdf/download.php?id=b510cad397455e24047ec5c8c286b149aa7a8a&type=P&term=Philips%2520XQ5002Hopefully it won't be hard to determine the pinout through the glass envelope.