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#1
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Funny ad from 1951 on metal CRT"s.
Here is an ad on Ebay--touting the metal picture tubes. Saying how they have advantages over normal tubes, are safer, and have better pictures.
I believe history has proved otherwise...other than the lighter weight part... http://www.ebay.com/itm/1951-USS-Uni...item27fc756e82 |
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#2
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The B&W tubes don't seem to have suffered near as bad as the color ones, plenty of good 16 and 19" tubes kicking around. Can't say that for the ever elusive 21AXP22.
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Evolution... |
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#3
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So what were the big decision factors behind all glass, and the metal/glass
combo tubes....? Was it the manufacture of the bell that was hard to do in glass ....? Was it weight...? Was there safety concerns about the large glass envelop imploding and all the glass flying that made them wanna use the glass/metal combo....? In the ad it's just put out by US Steel, so it's obvious here that there is at this time a choice in construction, and they are trying to get manufacturers to consumers to ask for glass metal tubes for their industry..... Was there consumer involvement in the sales - end use so to speak - ? Did consumers ask for either design....? I know each company touted the items they used as being the "better" of any choices they may have made, and it would show up in their literature.... But did customers actually have any preference...? I can't imagine it would have made much difference.... Some of the tube radios I know did make it a selling point if they had a high tube count..... .
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Yes you can call me "Squirrel boy" |
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#4
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That ad was obviously an attempt to stave off the likely loss of business that US Steel was going to incur due to the advance of all glass picture tubes that were coming to market at the time that ad was published. IN the end metal tubes lost out to all glass because the all glass B&W bulbs were "turn key" IE: they came ready to use from the glass manufacture. The metal tubes had to be sourced from both a glass manufacture, and US Steel for the funnel. Then the face plate and neck assembly had to be fused to the metal funnel at the crt manufacture. With all glass bulbs, the crt manufacture only had to phosphor the face, install the gun, and evacuate. Metal funnels were destined for obsolescence. They were dinosaurs in the world of technology that advances very rapidly.
In the end all glass bulbs were made possible, due to the huge growth in, and consumer demand for, larger screen tv sets. With the large demand, it became cost effective to tool up the large expensive molds at the glass manufacturer (Corning?) that were required for the mass production of all glass bulbs. When they perfected frit glass, which enabled the construction of the all glass, 2 piece 21CYP22 color crt, it made the 21AXP22 obsolete, and the era of metal tubes ended. And I say good riddance to bad rubbish. The primary reason for 15GP22's, 19VP22's, and 21AXP22's going bad is the fact that the welds on the metal components are prone to leaking. If frit glass had been avaliable to make all glass color crt's right from the start, we wouldn't have such a limited supply of these rare, early color crt's today.
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Vacuum tubes are used in Wisconsin to help heat your house. New Web Site under developement ME http://AntiqueTvGuy.com |
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#5
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But we get to have fun hunting them down!
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Evolution... |
| Audiokarma |
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#6
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Wouldnt an all glass tube be safer for high voltage also? Less hazaard to wannabe tv servicers.
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#7
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Quote:
For a brief time, there were advantages: 1. Lightweight, at a time when most products were "slightly higher West of the Rockies" due to shipping charges. 2. A moderate degree of inherent implosion protection, since the FP glass was put in compression as the assembly cooled after the FP was attached. 3. Larger sizes for low production sets, as expensive glass molds were not needed. I doubt that the 19", 24" and 30" inch sets would have been made had metal funnels not been used. 4. Better viewing, due to flatter screen, which helped to avoid/reduce room glare. jr |
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#8
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The magazine ad was dated June 1951, same month & year I was born!
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julian |
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