Bygone Technology and Useless Items.

[AC/HL]

I bought some of those CFLs when they were 2 for a £1, my kind of bullying! What it does highlight is the escalating pace of change. LEDs were an expensive dream when CFLs were first promoted, now just a few years later they sweep everything before them. What next?

[IanBland]

Well, fluorescents have been on the market since 1938 so it's been quite a wait for a replacement! It does amuse me how many dystopian science fiction movies are now obsolete too, since they invariably create atmosphere with switch starters blinking failed tubes on and off. The grimy industrial future just won't be the same without the bink bink binking.

One thing I will not miss is 8 foot tubes. Trying to get one into a chain-suspended fitting on my own was one of the least pleasurable parts of my maintenance career. Not least because I am susceptible to quite a tingle from the glass.

Seems like only yesterday we were prohibiting copper/iron ballasts.

[emeritus]

Is it still a requirement for new properties to have at least one of those awful 3 pin BC lampholders that only take a very expensive CFL lamp? It's time they were declared obsolete: my son used to work for a housing association where every property had these fitted in every room and the residents always had problems in getting replacements, sometimes resorting to table lamps for which cheap and readily-obtainable bulbs were obtainable. .

[IanBland]

Emeritus-

One would hope so. But then local councils have a fascination with strange specifications. They're still specifying 2D light fittings! Come to that, when we moved into a new build Development Corporation house in 1980 there was a ban on TV aerials so everyone was forced to use another now gladly bygone technology, the Reddiffusion "wired TV" system (I'm not going to dignify it with the term "cable TV") with the selection box on the wall. Because council tenants don't deserve remote controls, or the ability to use video recorders or TV games. What the benefit was supposed to be remains a mystery.

The one good thing Robert Maxwell ever did was buy Rediffusion and asset strip it into oblivion, rendering that form of TV broadcasting valid for this thread.

[SiriusHardware]

Originally Posted by avocollector

of course a ZX81 in it's original box up in the loft.

You'd better dig that out and have a look at it, there is a common issue with the PVC in the PSU leads welding messily to the polystyrene packing inserts if they are left touching each other. It happened to mine: I store the PSU separately now.

[Richard_FM]

Originally Posted by IanBland

One would hope so. But then local councils have a fascination with strange specifications. They're still specifying 2D light fittings! Come to that, when we moved into a new build Development Corporation house in 1980 there was a ban on TV aerials so everyone was forced to use another now gladly bygone technology, the Reddiffusion "wired TV" system (I'm not going to dignify it with the term "cable TV") with the selection box on the wall. Because council tenants don't deserve remote controls, or the ability to use video recorders or TV games. What the benefit was supposed to be remains a mystery.

It was mostly intended to improve reception in areas with a weak signal.

I've heard the British Relay systems were effectively frozen technologywise after being taken over by Visionhire, leaving only lucky subscribers with transistored colour sets, otherwise they were left with B&W and colour valve sets.

[McMurdo]

It was mostly intended to improve reception in areas with a weak signal

Many parts of Stoke were on rediffusion. Aerial reception was poor from Sutton Coldfield until the relay at Fenton was built. Granada, as it was by then, issued set top tuners and rooftop aerials at that point to keep the old Mk4 tv's working!

My useless bit of technology is a Chesterman imperial micrometer calibrated in "thou's". A lovely cased quality instrument I was given and will never use.

[TonyDuell]

My useless bit of technology is a Chesterman imperial micrometer calibrated in "thou's". A lovely cased quality instrument I was given and will never use.

Why ever not? A micrometer is almost essential if you do lathe work and the like. I routinely use a Moore and Wright 'Tenth's Mike' (this reads in thou's, but has a vernier scale round the barrel, allowing you to read it to 1/10000"). If you need a metric measurement, it's pretty easy to convert the reading.

Aside #1 : I have a set of claimed-to-be metric feeler gauges, the thickest 2 blades of which are are marked .38mm and .63mm. Yes, 15 thou and 25 thou respectively.

Aside #2 : A test whether somebody is a scientist/engineer or not is to ask them to pronounce the words 'unionised' and 'thou'

[The Philpott]

I find the imperial micrometer easier (ie quicker) to read than the Hilka Metric one i got recently.

Ian's reference to faulty fluorescents as part of atmos. in sultry films strikes a chord. Eraserhead and Twin Peaks wouldn't have been quite the same without this.

[Dave Moll]

Like Tony, I too have a micrometer calibrated in "thou". If I need a measurement in millimetres, I simply multiply the reading by 39.4.

[Station X]

Originally Posted by McMurdo

My useless bit of technology is a Chesterman imperial micrometer calibrated in "thou's". A lovely cased quality instrument I was given and will never use.

My lathe has the feed screw dials marked in thous so I used to use an imperial micrometer when working out how much I needed to "take off" a work piece.

Nowadays I use a digital vernier caliper which can be switched to read imperial or metric. So if I want to turn something to a diameter of say 5.65mm, I set the caliper to that then zero it and switch to imperial. Next I measure the work piece and the caliper tells me how many thou oversize it is. Then I take off half that amount.

[barrymagrec]

An imperial micrometer is pretty handy if you are measuring Jaguar valve shims which are in imperial sizes. I think the same would apply to a lot of the vintage technology of interest on this forum.

[Radio Wrangler]

Originally Posted by TonyDuell

Aside #1 : I have a set of claimed-to-be metric feeler gauges, the thickest 2 blades of which are are marked .38mm and .63mm. Yes, 15 thou and 25 thou respectively.

After metrication, PCBs were laid out on a 2.54mm grid.....

David

[barrymagrec]

Yes indeed but they were before - nothing changed and most (not all) component packages still originate in the US and are imperial.

I was greatly amused in the early days of metrication when our drawing office produced a drawing entitled "Metric Standard drawing - General Arrangement for 1/4 inch Tape Deck"

[Richard_FM]

It's interesting that film is measured in millimetres widthwise, & in feet lengthwise.

[Station X]

I can remember ordering 100 metres of six and a half pound wire. ie a mile of it weighed six and a half pounds.

[barrymagrec]

Originally Posted by Richard_FM

It's interesting that film is measured in millimetres widthwise, & in feet lengthwise.

An early example of Hybrid technology.....

Conversely early post war tape machines used 1/4 inch tape and ran at 77cm/s.

[G6Tanuki]

Originally Posted by IanBland

But then local councils have a fascination with strange specifications.

True: I remember seeing in the early-1980s a Council-issued tender document for a signal-distribution system to be installed as part of a refurb of some old-peoples' flats. I had a UHF repeater on the roof and wanted to know if there was any likelihood of EMI issues.

The specification in the tender only required the system to work on the old 405-line B&W VHF TV frequencies. No mention of 625 lines, colour , UHF, or even FM-radio! Obsolete even before it would go into service.

[Richard_FM]

Originally Posted by Station X

I can remember ordering 100 metres of six and a half pound wire. ie a mile of it weighed six and a half pounds.

I've heard in the 2nd World War the RAF used 9 Inch Manilla rope for glider tow ropes. This figure referred to the circumference, and I presume was made from fibres from the Philippines.

[TonyDuell]

I could go on for hours about imperial measurements...

If you work on 1960s/1970s American equipment (in my case, Teletype machines, computers from HP and DEC, etc) then you need a good set of inch-sized tools, including some sizes not commonly found in the UK, like 9/64" Allen keys and 11/32" spanners. The latter in particular is hard to find.

At least one manufacturer has different part numbers for a 1.27mm Allen key and a 0.050" one. So far I have not been able to determine any differences..

It is a source of annoyance to many screwcutting lathe owners that the conversion between inches and millimetres is 25.4. 254 factorises as 127*2, and 127 is prime. So to cut an exact metric screw on a lathe with an imperial leadscrew or vice versa you need a 127 tooth gear somewhere in the train. However there is a workaround. 127*21*3 = 8001. So you can approximate the 127 tooth gear as 8000/(21*3) (rather than 8001 in the numerator), the only unusual gear you need then is 21 teeth. It's not accurate enough to make a micrometer screw, say, but it is good enough for fastenings.

And my father told the story of the time, shortly after we were supposed to have gone metric that he went to buy some wood. He asked for 'A piece of softwood, 10cm by 5cm, about 1.8m long'. The chap thought for a moment and shouted to his mate in the timber yard 'Get us 6 feet of 4 by 2'.