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18th Nov 2017, 5:06 pm | #1 |
Heptode
Join Date: Apr 2016
Location: Cheltenham, Gloucestershire, UK.
Posts: 875
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Fascinating Documentary about Quartz crystal manufacturing
Quartz crystal manufacturing - State-side during WWII.
Note well: the super-clean conditions; the preponderance of PPE; the massive automation; the extensive safety precautions etc. etc. ..... NOT!!!! https://youtu.be/b--FKHCFjOM
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19th Nov 2017, 5:44 am | #2 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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Re: Fascinating Documentary about Quartz crystal manufacturing
Those crystals look to be the same size as those fitted in the smaller FT243 holders which were in such great demand during the Golden Age of 2m AM ~1970. There were just a few crystals of around 6MHz and 8MHz that would multiply up the the upper end of the 2m band, of which the 8.100MHz was most common. I recal taking some of those crystals and abrading them with "Vim" scouring powder to raise their frequency just a little to escape QRM with other people owning 8.100's.
What surprises me about that film is the very cursory way the crystals were dried, using only a brief blast of compressed air, after coming out of the etching solutions. After scouring and washing, we always baked them dry in the belief that activity and stabilty demanded this. I wonder what the X-ray "remediation process" was suppose to do? I wonder if that war-time film represents the truth, the whole truth and nothing but the truth? B
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19th Nov 2017, 8:08 am | #3 |
Moderator
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Location: Fife, Scotland, UK.
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Re: Fascinating Documentary about Quartz crystal manufacturing
I didn't see any mention of temperature cycling to get them over the worst of their ageing shift. Maybe the X-ray treatment accelerated some of the initial settling? If so it would leave those crystals with less ageing to eventually do, while those not treated would continue drifting further. It never lasted as a mainstream technique. Plated electrodes came along anyway.
David
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19th Nov 2017, 5:19 pm | #4 |
Nonode
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
Posts: 2,887
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Re: Fascinating Documentary about Quartz crystal manufacturing
Very interesting,in many ways, thank you for making it available.
HSE would have field day, and any health and safety training course should show this and ask students to note any possible hazards, Risks, and ways of reducing accidents! Cheers John |
20th Nov 2017, 2:37 am | #5 |
Dekatron
Join Date: Apr 2009
Location: Oxfordshire, UK.
Posts: 4,935
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Re: Fascinating Documentary about Quartz crystal manufacturing
I'd suggest that the filming was highly staged and contrived. It was probably intended to be shown to young military radio operators during training, who had to be kept interested. For that purpose it would have been very good
The young woman who was shown doing the etching had very long, highly manicured and painted fingernails. In real life, I bet she worked in the office; probably the boss's secretary. Etching quartz almost always involves hazardous fluoride solutions; they probably didn't want to show their commercial rivals how they carried out such processes, nor other aspects such the ageing methods mentioned above. I'd say that using it for modern HSE training would probably be slightly unscrupulous when you don't how they really did things. B
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Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch. |
20th Nov 2017, 1:25 pm | #6 |
Nonode
Join Date: Nov 2016
Location: Aberaeron, Ceredigion, Wales, UK.
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Re: Fascinating Documentary about Quartz crystal manufacturing
Yes I agree with your observations, I did think that the operatives were well groomed. In one shot I did notice one finger cut, not surprised slicing the crystal! As I said all very interesting.
Incidentally apart from using the crystals for Radios, we used crystal stacks in pressure transducers to measure performance of rocket motors etc etc. Cheers John |
20th Nov 2017, 1:38 pm | #7 |
Octode
Join Date: Nov 2003
Location: Bath, Somerset, UK.
Posts: 1,805
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Re: Fascinating Documentary about Quartz crystal manufacturing
Looking at the painstakingly time consuming process from start to finish, I shall never see wartime quartz crystals in the same light ever again. They must have been so expensive at the time, I will treasure the examples that I have.
Neil
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27th Nov 2017, 11:45 pm | #8 |
Octode
Join Date: Jan 2007
Location: Dorridge, West Midlands, UK.
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Re: Fascinating Documentary about Quartz crystal manufacturing
Thanks for the link most interesting, it is the first time I realised how complex it was to make a crystal, I wonder does anyone know how much it has changed.
Chris |
28th Nov 2017, 9:46 pm | #9 | |
Dekatron
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Location: Oxfordshire, UK.
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Re: Fascinating Documentary about Quartz crystal manufacturing
Quote:
B
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