28th Mar 2018, 10:19 am | #181 |
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Re: Bygone Technology and Useless Items.
Also the infra red sensitivity allows you to quickly
check if a remote control is working. |
28th Mar 2018, 10:25 am | #182 | |
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Re: Bygone Technology and Useless Items.
Quote:
Lots of photos, from lots of different angles..... |
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28th Mar 2018, 10:33 am | #183 | |
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Re: Bygone Technology and Useless Items.
Quote:
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28th Mar 2018, 10:37 am | #184 |
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Re: Bygone Technology and Useless Items.
The Dictaphone Ultravox and similar dictation machines that used a flat sheet of magnetic film wrapped around a roller for recording. Fun to play with because you can hold the head still and scan the same bit of sound over and over as a loop, or pull the head across the roller and speed the sound up without altering the pitch. Now useless because you can't get the magnetic sheets.
Carbon paper is still useful stuff for tracing purposes.
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28th Mar 2018, 10:47 am | #185 |
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Re: Bygone Technology and Useless Items.
I used to use carbon paper with the dot matrix printer of my pcw8256 . It worked OK with 60gsm paper.
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28th Mar 2018, 6:40 pm | #186 |
Nonode
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Re: Bygone Technology and Useless Items.
I've heard of someone buying a new digital camera from a certain catalogue shop only to find some "nude reader's wives" styles photos still left in the memory.
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28th Mar 2018, 8:44 pm | #187 | ||
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Re: Bygone Technology and Useless Items.
Quote:
They think thy're so clever, using their phone to tweet, facetime, e-mail etc, yet they haven't the sense to use the same phone to take a picture of something before they strip it down! |
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29th Mar 2018, 2:27 am | #188 |
Heptode
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Re: Bygone Technology and Useless Items.
I sometimes take photos of mechanisms and then draw a diagram, because a good diagram can explain how the components fit together, or show you the inside and outside at the same time.
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19th Apr 2018, 11:55 am | #189 | |
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Re: Bygone Technology and Useless Items.
Quote:
IIRC these used a hybrid photographic and thermal process, involving an intermediate sheet of paper or film, pink in colour. The initial exposure was I believe a dry photographic process that used a high powered lamp. The lamp was controlled by a simple run back timer so as to control the exposure time. The second stage was a thermal process in which the pink intermediate film and the white paper were passed between heated rollers and the invisible image held on the pink film thereby printed on the white paper. Although the lamp got very hot, I do not believe that this heat was relevant to the process, it would be too variable according to room temperature and also how many copies had been made. The heated rollers were presumably under thermostatic control to give consistent results. |
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19th Apr 2018, 1:10 pm | #190 |
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Re: Bygone Technology and Useless Items.
I remember going to a demonstration of one of those copiers when I was a student in the late 1960's. The only problem for us was that the only paper available was an American size (I can't recall if it was US letter or 8" x 10") and the stuff we might need to copy was either A4 or Foolscap.
The engineering department's copier was a Kodak wet-process one that produced a tone-reversed image, meaning that you had to use the first copy as a negative if you wanted proper copies. It coped quite well with continuous-tone and coloured images, unlike the contemporary Xerox copiers that were completely blind to blue and unable to cope with images. |
19th Apr 2018, 1:34 pm | #191 |
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Re: Bygone Technology and Useless Items.
I remember that blue blindness, when did they overcome the problem? And how?
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19th Apr 2018, 1:39 pm | #192 |
Pentode
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Re: Bygone Technology and Useless Items.
I'm wondering if we're reaching the end of days for the analogue (i.e. not class d) audio amp. Obviously the audiophile brigade will keep almost any old tech alive to some extent but in terms of mass-market consumer products they seem to be moving into history.
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19th Apr 2018, 2:09 pm | #193 | |
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Re: Bygone Technology and Useless Items.
Quote:
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19th Apr 2018, 4:03 pm | #194 |
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Re: Bygone Technology and Useless Items.
Since a Class D amplifier is basically a special kind of variable switched-mode power supply (much like a class AB amplifier is a special kind of variable dissipative voltage regulator), are we ever likely to see ICs combining the power supply and amplifying functions; meant to be powered from rectified mains, with optically-isolated audio inputs, and using the switching transformer to provide isolation for the speaker?
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22nd Apr 2018, 4:32 pm | #195 |
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Re: Bygone Technology and Useless Items.
I still have a Polaroid 104 model Land Camera (including the armpit clip - if it was cold you put the metal clip in your armpit to warm it up then put the exposed film in the clip to develop!!), umpteen film cameras (Ashai Pentax etc), turntables and of course a ZX81 in it's original box up in the loft. I am just wondering WHY? LOL.
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22nd Apr 2018, 5:36 pm | #196 |
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Re: Bygone Technology and Useless Items.
Music players on the top deck of double decked buses.
We had them playing in South Yorkshire. I think they might have been 8 track machines, or something with a tape on a continues loop. It played easy listening music such as Don Mclean Castles In The Air and had adverts and jingles. Such as "sounds in motion in stereo". The idea was that it would cut down on vandalism on the top deck of the bus. I suppose it worked to some extent. |
22nd Apr 2018, 8:14 pm | #197 |
Hexode
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Re: Bygone Technology and Useless Items.
I bought a power amplifer a couple of months ago, one of these-
https://www.amazon.co.uk/gp/product/B003UHO4Q6/ Pure analogue, even the power supply which is your standard toroidal, bridge, pair of caps job. Maybe it's my age, but I don't trust using a switched mode power supply as an audio amplifier. It feels somehow against nature to do so. Especially considering the sheer amount of noise cheap switched modes fling out into the luminiferous aether. |
22nd Apr 2018, 8:27 pm | #198 |
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Re: Bygone Technology and Useless Items.
Likewise the landline telephone.
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22nd Apr 2018, 8:32 pm | #199 | |
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Re: Bygone Technology and Useless Items.
Quote:
The sheet you wanted to copy/duplicate was wrapped around the first drum. The 'screen print master' was placed around the second drum. The machine was then activated and the drums [may have been one long one] revolved. The original was scanned, the master was pierced by a tiny point by an arc of which could be seen varying in intensity. The master was then taken off the main machine and placed around the drum of the printer. Ink was squeezed through the tiny holes producing high quality prints/copies of the original. That is about all I can remember. An expensive palava! The scanning took around 20 mins per A4 sheet. John |
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22nd Apr 2018, 9:08 pm | #200 |
Hexode
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Re: Bygone Technology and Useless Items.
From a search of this thread, it appears that surprisingly nobody seems to have mentioned the imminent demise of the fluorescent lighting, particularly the compact form, just scant years after the governments tried bullying everyone into using them. The ones in my home are only in use until they fail and will then be replaced with LEDs.
Effectively they're already obsolete but just hanging on. Regarding Scotch Copiers, around the age of 10 I spent a phase desperately wanting to own one as I'd started drawing my own comics and wanted to "print" them I remember them being hopelessly expensive at something like £50 each. |