Magic eye exposure to U.V radiation - UK Vintage Radio Repair and Restoration Discussion Forum

Alf · 12th Sep 2005, 11:05 pm

Wonder what your views are on this item?

http://www.dialcover.com/eyetube.html

Paul Stenning · 12th Sep 2005, 11:17 pm

Well the test seems reasonably conclusive to me.

I have a flourescent light in my workshop and the magic eyes in the sets in there continue to work fine. My Philips Reverbeo in the spare bedroom/office gets a bit of sunlight through the window each day; it is used regularly and still has a nice bright magic eye.

I wouldn't want to expose sets to strong sunlight for an extended period anyway as it could fade the fabric and affect the case finish. But I don't feel I need to add magic eye deterioriation to that list of reasons.

Jeremy M0RVB · 12th Sep 2005, 11:25 pm

Fascinating. A blast from an electron beam is ok but a bit of sunshine is not...

They should do a better test, i.e. cover part of the eye up and expose the rest to see if there is a difference in intensity.

Hmmm... I guess these guys did take the eye tube into the shade... they didn't just assume it had gone dim 'cos they could not see it due to the brightness of the sun! (argh, I said 'tube'! Must find soap to wash mouth out with...)

Heatercathodeshort · 13th Sep 2005, 6:57 pm

Hello,
Don't worry about it Lads...If you started the experiment now we would all be dead before the experiment yielded any results.....Very sad! Regards, JOHN.

Danny · 13th Sep 2005, 9:22 pm

Well once the experiment is done if its gone dark then he could put it on flee bay and sell it as nos and then blame it on the postie. i have read in an old practical television that if you leave a long percistance tube in the sunlight it would make the glow shorter so it could be used for tv!. I recently bought a VCR97 that had spent two years outside in the rain and snow, also in direct sunlight it is now in a home made television and apart from the contacts neading a good clean it still works now how many modern devices would survive with that sort of treatment!.

Darren-UK · 13th Sep 2005, 10:43 pm

If this really was of any major concern, I'd have thought radio manufacturers - at least of quality sets - would have installed a uv filter in front of the magic-eye. Maybe I'm just being silly.... or logical.

GMB · 14th Sep 2005, 11:58 am

This raises again what is the detailed chemistry of the phosphor aging process?

Darren-UK · 14th Sep 2005, 1:02 pm

It's probably more a question of the 'radio ageing process'. We have to remember that, although many old valve radios etc are still going strong today, they were built with an intended lifespan which they've now well exceeded.

For example if a radio built in, say 1955, had a guarantee period of three years, this may well expire long before the phosphur life of a magic eye was calculated to expire under normal service conditions - so it wasn't seen as a problem by the manufacturers.

Then again, were these supposed problems of phosphur degeneration actually known about 40 or 50 years ago or have they simply manifested as time has marched on ?

12th Sep 2005, 11:05 pm	#1
Alf Hexode Join Date: May 2005 Location: Wigan, Greater Manchester, UK. Posts: 479	Magic eye exposure to U.V radiation Wonder what your views are on this item? http://www.dialcover.com/eyetube.html

12th Sep 2005, 11:17 pm	#2
Paul Stenning Administrator Join Date: Dec 2002 Location: Cardiff Posts: 9,073	Re: Magic eye exposure to U.V radiation Well the test seems reasonably conclusive to me. I have a flourescent light in my workshop and the magic eyes in the sets in there continue to work fine. My Philips Reverbeo in the spare bedroom/office gets a bit of sunlight through the window each day; it is used regularly and still has a nice bright magic eye. I wouldn't want to expose sets to strong sunlight for an extended period anyway as it could fade the fabric and affect the case finish. But I don't feel I need to add magic eye deterioriation to that list of reasons. __________________ Paul Stenning Forum Admin/Owner and BVWS Webmaster

12th Sep 2005, 11:25 pm	#3
Jeremy M0RVB Hexode Join Date: Jul 2003 Location: Leeds, West Yorkshire, UK. Posts: 458	Re: Magic eye exposure to U.V radiation Fascinating. A blast from an electron beam is ok but a bit of sunshine is not... They should do a better test, i.e. cover part of the eye up and expose the rest to see if there is a difference in intensity. Hmmm... I guess these guys did take the eye tube into the shade... they didn't just assume it had gone dim 'cos they could not see it due to the brightness of the sun! (argh, I said 'tube'! Must find soap to wash mouth out with...)

13th Sep 2005, 6:57 pm	#4
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Magic eye exposure to U.V radiation Hello, Don't worry about it Lads...If you started the experiment now we would all be dead before the experiment yielded any results.....Very sad! Regards, JOHN.

13th Sep 2005, 9:22 pm	#5
Danny Heptode Join Date: Jul 2003 Location: North Walsham, Norfolk, UK. Posts: 516	Re: Magic eye exposure to U.V radiation Well once the experiment is done if its gone dark then he could put it on flee bay and sell it as nos and then blame it on the postie. i have read in an old practical television that if you leave a long percistance tube in the sunlight it would make the glow shorter so it could be used for tv!. I recently bought a VCR97 that had spent two years outside in the rain and snow, also in direct sunlight it is now in a home made television and apart from the contacts neading a good clean it still works now how many modern devices would survive with that sort of treatment!.

13th Sep 2005, 10:43 pm	#6
Darren-UK Retired Dormant Member Join Date: Apr 2003 Location: Blackpool, Lancashire, UK. Posts: 4,061	Re: Magic eye exposure to U.V radiation If this really was of any major concern, I'd have thought radio manufacturers - at least of quality sets - would have installed a uv filter in front of the magic-eye. Maybe I'm just being silly.... or logical.

14th Sep 2005, 11:58 am	#7
GMB Dekatron Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 3,099	Re: Magic eye exposure to U.V radiation This raises again what is the detailed chemistry of the phosphor aging process?

14th Sep 2005, 1:02 pm	#8
Darren-UK Retired Dormant Member Join Date: Apr 2003 Location: Blackpool, Lancashire, UK. Posts: 4,061	Re: Magic eye exposure to U.V radiation It's probably more a question of the 'radio ageing process'. We have to remember that, although many old valve radios etc are still going strong today, they were built with an intended lifespan which they've now well exceeded. For example if a radio built in, say 1955, had a guarantee period of three years, this may well expire long before the phosphur life of a magic eye was calculated to expire under normal service conditions - so it wasn't seen as a problem by the manufacturers. Then again, were these supposed problems of phosphur degeneration actually known about 40 or 50 years ago or have they simply manifested as time has marched on ?