Nixie clocks and other stuff!

[Yorkie]

In his thread about A22 specker fabric, Nick spotted a nixie clock that I'd made some years ago which featured on the website of Mike Harrison - 'Mike's Electric Stuff'. Nick and I had been in correspondence in 2010 about that an other things by email.

In his A22 Speaker fabric thread, Nick wrote:

Crikey - you're right - just checked - May 2010 we were talking about capacitor reforming and drifted onto nixie clocks. Mike himself admits that the design is lethal and nowadays he'd never publish something like that. He's a professional EE and makes amazing lighting rigs for bit stadia and art installations, e.g. he built this: http://news.bbc.co.uk/1/hi/world/americas/8066061.stm

Incredible guy - what skill and ingeunity!

Rather than take Nick's A22 thread further off topic, I thought I'd start another thread about the 'Mike's Electric Stuff' site and nixies in general. Firstly, the main site - if anyone on the forum hasn't yet visited it, it's well worth viewing. Such a lot of fascinating stuff on there, from scary teslathons to nixies, valves and any number of things too numerous to mention.

Main site:

http://www.electricstuff.co.uk/

The nixie clock gallery shows countless clocks that have been made around the world, and is testament to the skill and ingenuity that abounds. Some use 'rat's nest' wiring, others use perf-board, and some use printed circuit boards, though apart from Mike's own design, (two of which I built, and souced the PCBs from the States), no-one else gives any constructional details. The clocks range from simple ones using just one nixie tube, to designs which use several - at least six - to give hours mins and secs. Some have little neons as decimal places - others just space the tubes in pairs. Some of the builders also show considerable woodturning and metalworking skills.

http://www.electricstuff.co.uk/nixiegallery.html

There was a design in Elektor some months ago for a nixie tube theremometer.

My own next clock project will be a 'flip clock' - my younger son hankers after one - apparently they can be bought, but not cheaply. It won't involve any electronics - just woodwork, to make a little case in which to house the movement. Remember those clocks in electric cookers and bedside alarms etc which had digits that flipped for minutes and hours driven by a synchronous motor movement? John Birkett at Lincoln has had a few in stock for about 25 years so I collected a couple some months back and stripped them to the bare bones. (Just a pound each - see pic).

The other thing I fancy doing (one day?) is making a clock using a small 'scope tube. I have a BP3 tube (3" blue persistence). There are designs on internet, but they're not cheap or simple to make. And then there's the small Tesla coil project also on my 'to do list' of whimsical projects. I got as far as fettling up an old car ignition coil which is needed, and there for now, the project rests.

As a new member, Nick might be a tad reticent to mention his own website on nixes and other stuff. That doesn't stop me mentioning it! Check out his SMPS project to drive nixies:

http://www.desmith.net/NMdS/

Neat eh?

Rambled and dribbled Yorkie

[Joe]

That 'Live Chassis' clock has a certain allure.

- Joe

[Nick]

That 'Live Chassis' clock has a certain allure.

Mike's professional home is at http://www.whitewing.co.uk - on the main "UFO" project site at http://www.cinimodstudio.com/project/ufo...er-coffin/, you'll see he's credited with the electronics - the whole thing was controlled from the ground by SMS messages... very cute...

I know Mike through one of my (many) other interests - high energy physics - Mike is a stalwart of the UK Teslathon group of which one of my sons & I have partaken from time to time I designed a few sold-state TCs (SSTCs & DRSSTCs), including a rather novel doubly resonant one which has a bit of a writeup at http://4hv.org/e107_plugins/forum/forum_....php?72000 - the primary former was designed in SolidEdge and laser cut - http://4hv.org/e107_plugins/forum/forum_...90019.post - 4hv.org is dedicated to HV projects mainly, though its become a bit repetitive in recent years. Odd that Elektor was mentioned as Jan Buiting, the editor, asked me to write up the uDRSSTC project for them. However, we agreed subsequently that it was probably too dangerous...

I really don't get time to write up many projects - normally it only happens when I'm pressed to by others - there are many that really should get a page or two, but time does not permit it. The current DAC 90A rebuild may, if only because its made some people cross

'scope clocks are fun - there are several kits around and there are a number of small good tubes for this - going down my stock list, any of the following would be usable: CV1522, CV1597, DG 3-2, DG 7-32, DG 7-36, DG 3-91 (CV2302), E4103, VCR138 (10E/407), 3BP1, 3L01i, 6L01, 6L02A and many more. All you need is electrostatic deflection with reasonable sensitivity - eBay is your friend here - they tend to have quite a few ex-USSR ones. We cover 'scope clocks fairly frequently on neonixie-l. The HT can worry some people though...

Flip clocks are cool too, though my personal favourite is at http://yugop.com/ver3/index.asp?id=3

[Yorkie]

Thanks for a most interesting and eclectic post Nick.

The UFO is an amazing bit of kit - highly convincing. UFOs are just that - flying objects which remain unidentifed until their identity is established. In the case of Mike's 'UFO' once its identity is established, it ceases to be a' UFO' and becomes a 'FO! I hadn't realised that Mike's activites were so varied and high level. Where do such people (you included!) find the time? Your uDRSSTC project must have involved a great of development - nice double sided PTH PCB! Even sourcing components can be quite a challenge these days.

As to your DAC90A project, DAC90As do evoke different views and emotions, rather like Marmite - you either love it or hate it. It has its fans, but it makes others want to reach for the the bucket! With me, it's a generational thing - I was nine when the DAC90A was put out on rental in its hundreds of thousands, and we had one stuck on the shelf throughout my teens until it packed in yet again (UL41), and was put out for the bin men. I always thought it was a miserable looking thing and was glad to see the back of it. When I see one now, it's just an echo of the past - years of post-war austerity, ration books, shoddy goods and make do and mend.

It won't evoke those feelings in others of course. Some consider them a thing of beauty and an icon of the late 1940s. (I've lost count of the number of times I've seen either Neville Chamberlin announcing that we we're at war with Germany, or Churchill in 1945 telling us that 'we may allow ourselves a few moments of rejoicing'!)

In the early 1970s I attended a year's evening classes on radio and TV servicing. The tutor ran his own shop and had repaired thousands of DAC90s over the years. His theory as to the design shortcomings was that the brief that Bush gave to the engineers was: 'Design a radio that works well, then progressively remove parts until it stops working, then put the last part back'. A bit flippant, it's true, but it won't have been far off the mark. It's design shortcomings are well known and much stated, but it's a fact at a time when most families could not have afforded to have bought a radio, rental companies favoured them and put them out in their untold thousands.

One of its plus points - which we forget these days, when we can afford radios in every room - is that it was 'transportable' within the home, but it wasn't unique in that. It didn't need an aerial so could be taken from room to room. (You didn't even need a power socket - just stick an adaptor in the light socket for the bulb and the radio!).

I understand that after several years, Radio Rentals et al told customers they would no longer repair them and that customers could buy the set if they wished for ten shillings. I suppose that's why so many still survive - they got put up in the loft when the UL41 gave up the ghost, to emerge decades late and end up at car boot sale or on e-bay. At least they have the merit of not getting infested with woodworm!

There are two sellers on e-bay who restore them and bring them up to standard. (Remove the dangerous mains connector and fit a three core non reversible flex, using the earth to earth the metal speaker grile, improve the dial lights, replace the caps, test and give a one year warranty). One of those restorers recently sold two sets - one at £225, the other at £285. The mind boggles, but it does show that reliability and safety triumph over originality in the minds buyers. The DAC90A is so commonplace that originality is an irrrelvance. Yet people will still pay upwards of £15.00 on e-bay for a two-pin mains socket. (One of the restorers fits a 6.3V transforer for the dial lights).

Your DAC90A nut and bolt strip-down and rebuild (a-la kaylee) has certainly set a few tongues wagging Nick, but you've shown how such things should be done - carefully designed layout, ultrasonic cleaning of switches, tuning cap etc. Beats sticking it in the dishwasher, as some have advocated, (or as I did in 1959, shoving it in the dustbin)

Yours must be well on the way to completion!

Better sets were soon on the market, but I don't think any have the same popular appeal as the DAC90A. I'd nominate the Stella 105U of 1952, which I think is a more cheerful looking set. It has dial lights that are fit for purpose, a dial that can be easily seen, and performs better, though has a slightly higher component count than the DAC90A. (37 caps/25 Rs, compared to 29/18 in the DAC90A. Admittedly it's a rat's nest beneath the chassis, which compares unfavourably with the DAC90A tagboard.

I dare say that anyone on the lookout for a DAC90A at a car boot sale would walk past a Stella 105U without giving it a second glance.

If I had to nominate a favourite small transportable set, I think it would be the Murphy U198 of 1954, and later, the Pye 'R33'.

Rambled and dribbled Yorkie.

(I used to work in a helium factory but I resigned - I'm not having people talk to me like that!).