4681 forum posts
I think the Sinclair development was done nearby in Huntingdon or Ely. Acorn also started off in a couple of rooms up a narrow staircase on Market Square in Cambridge. Several years before the BBC computer I ventured there and they were trying out one of their boards in a slot machine. I think it was one of those or a Tangerine that was used as the first computer in Blake's 7 Liberator, before Orac.
852 forum posts
Hmm! just catching up after a couple of days and amusing reading the calculator threads, back in the 60's 70's I worked on production jig boring hence a lot of trig calculations all done with 7 fig logs and a mechanical Brunsviga calculator, sometime in the 70's the company bought us a Texas Instruments scientific calculator -- something of a revelation but at first we would make the calculation and see the result on the screen - lacking trust we then said better just check it and back to the logs and Brunsviga ! Did learn to trust it eventually though.
Also looked at Sinclair but they were incredibly slow, you put the info in then it took what seemed an age before the result was displayed -- worked OK bur not really a success in my book.
|164 forum posts|
After the motor stopped working on my mill, I started to troubleshoot it today. Before stripping anything down, and prompted by Neil's suggestion of the motor being at fault, I checked the resistance across the DC motor: open circuit. I looked at the motor and remembered that it has carbon brushes; clearly the next thing to check.
I hope that this is the problem. Now, where to get new brushes for a 20 year old German motor?
|Jim Nic||04/01/2018 16:24:00|
203 forum posts
As happened with the motor on my mill, you seem to have one completely worn brush and one less so. You should be able to measure the size you need and resort to good old e-bay where you will find many sizes of carbon brush for cheap money. Watch out that the springy end is the correct size and shape for your motor and then the brush itself can be easily and gently filed to size if necessary.
|larry Phelan||04/01/2018 16:37:20|
544 forum posts
What did I do today ? Not a lot ! but will give it Hell tomorrow !
|Neil Wyatt||04/01/2018 17:57:20|
16432 forum posts
I think my twin TDA2030 hifi amp may still exist. Made while I was still in school one channel used a 'development kit' board and I drew the other one up with a Dalo etch pen. A lovely old magnetic pickup module and two 8" dual cone speakers in chipboard cabs I made.
It got replaced by a Tripletone with dual concentric knobs, bits of a two-channel, four input guitar amp based on this definitely still exist....
My first 'custom amp' was an old Duette autochanger record player with the turntable replaced by a jack socket and a larger speaker built into the box. Lethal!
I then fitted a record player valve amp into the box of a defunct Trough-Line receiver. Probably the first ever stand alone Valve-preamp distortion unit
What I miss most was a distortion pedal built into a plastic stomp box from Maplin. It combined two simple 'fuzz' circuits, one using discretes, one using op amps that could be switched in series. It was a 'little' noisy but could destroy armoured vehicles at 100 metres. Called 'Doc's Monster Fuzz' it sadly got stolen. I have a recording of it in action with a 'mini phaser' and wah pedal...
776 forum posts
Hi Gary, my Curta is a mk2 complete with left hand metal case both in pristine condition, and yes a phenomenal piece of engineering condensed into a very compact space.
|Philip Rowe||06/01/2018 16:50:47|
|171 forum posts|
Stripped and cleaned an old 4 jaw independent chuck that had become sticky in it's operation, now works quite silkily (if that's a proper word). This chuck would have been purchasd by my late father in around 1935 and is stamped 'The Burnerd' and underneath 'Buck and Ryan'. Originally it had a backplate to fit a Myford ML2 but in the 70s this was changed to a larger backplate to fit a Super 7, being only 4" diameter I find it far more convenient for the sort of work that I do than the more usual 6" normally associated with the S7.
|duncan webster||06/01/2018 17:18:56|
2199 forum posts
Finished the rebuild of the electronics for my milling machine table drive. Mk1 had a PIC, but it wasn't fast enough really. I could have changed the code, but I no longer had the hardware to program PICs so I've re-done the whole thing with an Arduino. In the meantime of course I've now got the kit for programming PICs again, but I still have to learn how to use it. The actual drive motor is a stepper, saves having to have a declutch mechanism, and will allow me to drive it from a Division Master or similar in future
2904 forum posts
My last foray into high-ish power audio was a 50W per channel power amp for my car when I was in 6th form. It also contained my first switched mode power supply (I ended up in a job in that field a few years later), which boosted the 12V voltage up to a regulated 60V and was the key to getting a decent output. The back seats of the car were occupied by a couple of full sized Acoustic Research speakers held in by the seatbelts. If the weather was conducive, I could park up and bring the speakers out of the car for proper outdoor stereo listening.
|John Alexander Stewart||06/01/2018 20:17:53|
|750 forum posts|
Today, I did not pontificate about computers.
Instead, I'm working on a batch of injectors, DAG Brown design, but "metricated" and the 13 overflow caps are now slotted, using a specially made jig and file, rather than a 4.5mm end mill.
Also figuring out how to connect the steam to cylinder line on my new Shay locomotive - it did fit, before painting! Hmmm...
|1157 forum posts|
This was quoted in a mail to me some time ago but I believe your mill is an Emco F1 so should help with sourcing brushes, contact them directly at www.solenttools.co.uk/
ask for carbon brushes part no STL 0406
938 forum posts
In my 2CV there was a Tandy cassette player. 50W per channel, and every last Watt was needed to hear anything over the engine noise at 50mph. Listening was very wearing. Hi Fi was for those who didn't need to shout to be heard when travelling.
|164 forum posts|
Thanks for the link: I will give them a try next week.
|duncan webster||06/01/2018 22:59:10|
2199 forum posts
I wouldn't have thought a 2CV could produce sufficient horsepower to supply a 50W per channel amplifier
Edited By duncan webster on 06/01/2018 22:59:38
Edited By duncan webster on 06/01/2018 23:00:02
|John Olsen||07/01/2018 01:34:10|
|985 forum posts|
When I was studying radio technician qualifications during the seventies, one of the tutors had a then brand new HP35, but would not let any of us great unwashed near enough to even look without touching. So I rode my motorbike down to the HP office and asked to see one. Fine, they said, but we have the new model too, the HP45, would you like to see that? So the upshot was that I placed an order, leaving me about six weeks to raise the money. NZ$450, which would have bought a brand new small motorbike in those days, or a reasonable second hand car. (The minis were about $2000 new around that time.) So quite a lot of money to raise, and it took a bit of convincing for the bank to loan me the balance. Still, I think it paid for itself, I got really good marks in all my exams with it, and finished up going to University and getting an engineering degree.Around that time I bought an HP19C, which is programmable with a printer, all in a pocket sized calculator. (At least if you had large pockets in two senses)
So I still have the 45, but it needs a new LED or driver as some segments don't go, the 19C, and an HP35 that I was given along the way. There is a 41C here somewhere too that belongs to my son.
|Gordon W||07/01/2018 10:26:29|
|2011 forum posts|
I can still remember my great joy at getting a new plastic slide- rule.
604 forum posts
I still have my slide rule in the desk drawer, don't think I can remember how to use it though
Picture (taken this morning) for those too young to have seen a slide rule
713 forum posts
There's still a slide-rule on my desk, but I wonder how many people know how to use one? Many years ago, when I was a newspaper sub-editor, I used to use one to scale pictures, and the other subs wondered how I was able to instantly read off any width and depth I wanted. As for calculators, I decided I'd buy my first Sinclair when the price fell below £30. It didnt seem that long before I got a better one free in a jumbo pack of corn flakes.
|Gordon W||07/01/2018 11:43:33|
|2011 forum posts|
I still use a slide rule, near enough for engineering calcs. Calculator for adding up a string. My first tech. calculator had two sections and could do anything. Cost more than a weeks wages and the new puppy ( yellow lab ) chewed it up. Yesterday " repaired" a storage radiator that would not switch on. Just poked about a bit with a small screwdriver and all is well , for now. Have you seen the price of these things, and spares ?
This thread is closed.
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