Saturday, 31 December 2011

Want a shiny nickel plate finish?

Stage One

Ammonium Sulphate, 410g
Ammonium Chloride, 90g
Nickel Chloride Hydrate, 490g
Cobalt Chloride Hydrate, 10g.

That should be 1kg of powder. Grind it together with a large pestle and mortar. Don't worry, it's not going to blow your face off. We're not making bombs here. Take all sensible precautions though - you know what chemical shit can be like if you get it in the wrong place.

This is your "Stock Powder". Store it in an airtight container.

Stage Two

Ammonium Sulphate, 34g
Ammonium Chloride, 5g
Nickel Chloride Hydrate, 40g
Cobalt Chloride Hydrate, 5g.

Dissolve this in 0.73 litres of 5N sulphuric acid (careful now, use safety wear) and make up to one litre with distilled water.

This is your "Stock Solution". Store it in a suitable bottle.

Now rest well. The preparation is done. You can move on to Stage Three any time you like.

Stage Three

To make one litre of "Working Solution", add 50ml of "Stock Solution" to 55g of "Stock Powder", dissolve in 660ml of distilled water, then make up to 1 litre with more distilled water.

Stage Four

Connect your piece of metalwork (perhaps copper or brass) to the negative terminal of a power source (croc clips are good for this). This is now your cathode. Connect another piece of electro-conductive material (any metal or carbon but preferably nickel) to the positive terminal of the power source. This is now your anode.

Maximum current should be 15A per square decimetre of the anode and cathode but that's a bit heavy (and a bit dangerous) for home use. You'll get good results for small items just using one of those big fuckoff torch batteries or similarly rated DC power supply.

Complete the circuit by dipping your anode and your cathode into the "Working Solution", making sure they don't touch. Leave for an unspecified while. Could be minutes. Could be hours, depending upon your power source. Swish 'em about a bit every now and then.

Remove, rinse with water then polish with... polish. Metal polish is good. Lo and behold - a wonderful and most durable nickel plating that looks almost like silver.

Whoops - sorry Mr Murdoch. I forgot that this formula was one of your expensive "industry secrets", the knowledge of which I acquired from my Dad just before you sacked him and his work fellows. Hey Ho. I guess we just don't understand the meaning of confidentiality anymore.

Friday, 9 December 2011

Anti-Tardiness Event Console

Coming soon, my newly redesigned "Event Console" - a product designed for people who want their web site events calendar to remain largely independent of mainstream social media tools. Oh, and independent of any tardy, hired web-head who's in charge of your site updates of course. It doesn't matter how tired or static your web site has become, with this nifty little tool your web site will always look like it's up to date! You can even update your web site calendar from your phone whilst lying prone in a gutter after closing time.

Ignore the "Steampunk" console imagery (sample input screen shown here). The output is pure text streamed directly into your web site and formatted according to your own style sheet.

I have two clients working in Beta for several months now, and nothing's broken. Want some?

Thursday, 17 November 2011

Universal-ish power supply unit

Hobbyists and home experimenters will know the feeling. You're working on a little project and you know you're going to need power. Often this results in a mad search for a battery box and some cells that still have a bit of life in them, or perhaps you raid your collection of "Wall Warts" (which usually means you can't charge your phone or use your router until playtime's over). Wouldn't it be nice to have a dedicated power supply for these occasions? What a luxury.

Contemplating this problem earlier today, my gaze fell upon a heap (literally a heap) of old computer PSUs gathering dust in the corner of the Secret Laboratory. I always salvage stuff from old PCs - better gathering dust than going to landfill.. Some of the PSUs were of no further use anyway, being of the old "20-pin" format rather than the "24-pin" that modern motherboards require. Some were rated as low as 200W, which doesn't really cut the mustard with modern PCs. For years I had been tripping over the very solution to my problems. It was a classic "DUH" moment...

So, the next Secret Laboratory project is going to be the conversion of one of these old computer PSUs to a useful universal-ish general purpose power supply. If it's good enough for motherboards, it's good enough for the shit I build.

The plan is to source a compact yet safe housing for the PSU, to prevent busy little fingers from poking stuff (accidentally or deliberately) through any dangerous holes. Terminals will be presented for +3.3V, +5V and +12V outputs (either separately else via a voltage selector switch - I haven't decided yet). I may include -12V for those of you who like to muck about with devices that require it. I never did fully understand why op amps need the dual polarity thing...

If you're following this project, the bit you're going to be working with is the 20-pin connector (usually marked P1), seen here to right of centre. You can ignore the other connectors (far left) - they just route the same power to other computer peripherals (hard drives, etc). You can get everything you need from the 20-pin connector alone.

Of great importance! Mark well the following cable colours:

  • Orange: +3.3V
  • Black: Ground
  • Red: +5V
  • Grey: Power Good (optional signal)
  • Purple: +5V Standby (optional power)
  • Yellow: +12V
  • Blue: -12V (optional power)
  • Green: Power On

There's some redundancy in there, so you'll find several cables of the same colour. Trust the colours but use a meter to check the voltage lines. I haven't given pin numbers because they differ between the 20 and 24-pin standards.

To turn the PSU on, you must ground the Power On pin. I plan to use a simple on-off switch for that.

+5V Standby is always on, even without Power On grounded. I plan to have a little LED across this just to show that the unit is plugged in and ready to go.

Power Good goes high when the PSU is delivering the right voltages to all outputs. Again, I plan to have a little LED across this one. You can't have enough lights on your unit, you just can't. The more lights, the better it looks (and it's a real babe magnet - well, it's always worked for me).

Regrettably, I must inform everyone that electricity can be hazardous and you really mustn't go mucking about with stuff you know not what of. In particular, do not disassemble the PSU itself and, if you do and you see something that looks like a little can of baked beans for a pixie's din-dins, don't touch it else you might end up all dead (even if you're not plugged in). That's my legal disclaimer. Can we see if we can get through this project like grown-ups?

More news soon, as soon as I've found a suitable housing for the PSU...

Wednesday, 9 November 2011

The Lindsay Technique for tangle-resistant cable storage

I call this the Lindsay Technique because it was musician and rock climber Andy Lindsay who taught me. The technique is derived from rock climbing practice but it works equally well in the world of live music performance.

Happy tangle-free gigging!

Monday, 7 November 2011

Reclaiming your toothpaste

OK, not an invention as such but a super little tip for all of you with TDA (toothpaste depletion anxiety).

Coming next on The Secret Laboratory - a full video disclosure of the Lindsay Technique for non-tangling cables. A must for musicians...

Friday, 14 October 2011

CRAPULITE® - building material of the future

It is with no small measure of pride (and indeed a huge dollop of smugness) that The Secret Laboratory is able to release details of its latest invention, CRAPULITE®

This open-textured, lightweight yet strong medium is ideal for repairing large gaps in crumbling masonry or rotting timberwork.

CRAPULITE® is produced from a readily available and sustainable source of recycled material, combined with an all-purpose filler in a secret process known as “shredding and mixing”. The high content of tabloid material renders CRAPULITE® impervious to bookworm. With a skim of rendering and a lick of paint, even your surveyor won’t know it’s CRAPULITE®.

The Secret Laboratory is in the process of negotiating exclusive rights with the construction company Bodgitt & Leggit of Purley.

Tuesday, 16 August 2011

Drop -Tank sidecar

Current shed project is the conversion of a 1945 Hawker Tempest Drop Tank (used for carrying extra fuel) Into a useable sidecar body for my old Panther motorcycle. I have so far welded in a new nose section (as it was dropped on its nose) and made some cutouts for the passenger.

The cutout weakened the body considerably so I welded some 8mm round bar all round the aperture. This required considerable heating, which is when I discovered all the rivets and seams were sealed with lead! Interesting! Next stage is making brackets to fit the body to an old chassis I have 'in stock'

Thursday, 7 July 2011

Bijoux Stomp Box

Saw this on tinternet and thought can't be that hard. Baccy tin with a fax machine speaker hot-glued to the bottom (the fax machine's unfortunate demise was one Monday morning when it refused to take the paper for the tenth time!!), soldered to a mono jack socket which was drilled and mounted in the side of the tin. Critical part is to stick a heavyish metal disc to the shiny dome thing in the middle of the speaker. this one is about 35mm. I reckon a smaller one would give a higher sound like a tom tom.

Well it works ok, lid down and tap it with foot, sounds a bit like a kick drum. Probably would sound great through a PA . I am going to attach it to a plank so I can boot it properly.

Tuesday, 7 June 2011

Quilted Coffee Pot Cosy

It's sad really but every now and then I get an inexplicable urge to make a quilted coffee pot cosy. Perhaps it's just that I like watching my ancient Singer doing its stuff (how does it grab that loop from the bobbin below?) or perhaps it's just that the simplicity of the cosy allows even talentless idiots such as myself to create something of profound beauty. Many there are that have knitted a scarf but few go on to "turn the heel" of a sock. The coffee pot cosy is the scarf of the quilting world.

I made this one for Angi Webb's coffee pot. Her pot is 8" x 4.5" rather than the industry standard 8" x 4" and so this cosy is truly a custom item.

There you go Angi - a present for your new house, from the Secret Laboratory...

Saturday, 4 June 2011


How to cook prawns on a barbecue (little ones, not king prawns). You know the problem. If you pop them on the barbie individually then some inevitably fall through the bars and into the coals. Those that escape that fate must be turned individually - a tortuous exercise involving the loss of even more prawns and the burning of fingers. You could thread them on a skewer but small prawns are liable to be split asunder, leading to further prawn loss.

No more prawn loss with the Prawnvelope! To make your Prawnvelope you need a fresh mesh from a disposable barbecue (this might involve re-using an old mesh from a previous barbie so you can liberate a fresh mesh for this purpose).

Carefully fold the mesh in half. Don't crease the fold flat - use a former of some kind to get a prawn-sized radius on the fold.

Insert the prawns into the Prawnvelope. The mesh itself should hold them in place but, if you're nervous, use some food-bag "ties" to secure the edges of the assembly.

Now spray your prawns with oil, lemon juice, black pepper, whatever, and commit them to the barbie. You see how easy it is to flip them all in one easy action?

Another work of genius from The Secret Laboratory...

Wednesday, 1 June 2011


This is really a re-visited project. Some time ago I built a little pre-amp to boost the signal from my passive mando pickup (it's in the archives somewhere - check if you wish). Misdirected ambition caused me to create a compact "belt-mounted" device. It was nothing but trouble. Never again will I take on the East in the race towards miniaturisation. I will stick to what the Brits do best: Big fuckoff industrial-looking boxes with hardly anything inside but good in the long run.

Above you can see the business end of the unit. The socket marked "In" goes in and the socket marked "Out" goes out, sort of. This means you can plug things in at any level and they come out at line-level.

I'm really pleased to have discovered the secret of switching the power via the input socket so you don't need a separate power switch. Install a stereo (three-pole) jack socket for the input and connect the neg of the battery to the ring (in the tip/ring/sleeve architecture). When you plug a mono jack into the stereo socket, the sleeve and ring are shorted, the neg ends up where it's supposed to be, and, hey presto, you've got power to the circuit (this is a trick used in most effects pedals). Don't forget to unplug your cable after use else you'll drain your battery.

At the other end of the unit we have the "Smugness" knob. Although one minor side-effect is to make things louder, the primary purpose of this control is to enable geeks of electronic persuasion to treat anyone within earshot to a two-hour explanation of the difference between "gain" and "volume".

For me, the benefit is that I don't have to carry my heavy back line amp to simple sessions. I can plug my mando or bass into anything. Need more signal? You've got it...

Monday, 14 March 2011

New clear energy.

Here at the tank, our top chap Neville has got a cunning new plan to extract the H2 from H2O.
As all you boffins will know, this would mean we could convert our infernal combustion engines to run on the stuff, with the bonus that the exhaust is only water vapour. The only details I am allowed to divulge are that this process will involve a pair of scissors, and a large polished rock borrowed from his mate Macca. Nev assures me that this process will be cheap and highly efficient, and that the patent will be worth quite a bit, and could result in a noble prize.
Neville also believes that this will eventually involve the use of so many buckets of water as to lower sea levels, allowing the reclamation of farm land, and the planting of his favorite trees.
The only predicted drawback is that some atoms may be split in the process, so you may hear some bangs. These will be contained within the tank where we have a very large pot of glue ready.

AP 12.42. 14.3.11.

Saturday, 22 January 2011

Modding the Behringer - episode two

Welcome back. A quick update on the repair of the Behringer Ultracoustic ACX900:

One of the failed components on the Behringer was the switched 3-pole jack input on channel 2 which, being plastic, had sheared off at the base of the threaded bit. Our replacement (below) has a metal socket instead of a plastic one. Why this hadn't been fitted in the first place is a secret known only to Behringer. After all, channel 1 has a metal jack so why not channel 2?

Getting the old socket out was a nightmare. This is a double-sided circuit board with plated-through holes and lots of densely packed surface-mount components on the reverse (not visible here). The process of removing the old socket also removed some of the plating, so when we put the new socket in we weren't sure if there was anything left to solder the contacts to.
There are six miniature selector switches on this circuit board - four latched and two press-to-make. Two of these switches are shown below. Each switch is operated by a little button made of some kind of translucent plastic shit that fractures when you touch it (not a good quality in a button). Being custom-made to fit the Behringer console, these were not replaceable items (Maplin had never seen the like) and so we shored them up with glue from a hot-glue-gun. They won't fracture again, and they still transmit light from the indicator LEDs on the board. Bless the inventor of the hot-glue-gun. Get yours now and you will never regret it. A million uses.

The electronics sorted, the final step was to put the amp back together again. Below we are applying eff-off double-sided adhesive tape to secure the brown vinyl covering and to hide all evidence of our Great Hairy Leader's aggressive jigsaw-assisted entry. What you can't see in this pic is the wonderful new internal bracing behind the access panel, which is made of the finest seasoned Spanish oak, courtesy of Actreo Hardwoods (thanks Adam).

Rear view below. All done. You'd never guess we'd been in there, would you?

The moment of truth! We plugged it in and hired a crazy fiddler to take it through its paces. Sounds as good as new but we know it is technically sounder...

And finally - never a silver lining without diamonds falling out of his bum, our Great Hairy Leader made a beautiful bread board from the leftover Spanish oak.

Saturday, 15 January 2011

Modding the Behringer - episode one

"Apart from that, how did you like the show, Mrs Lincoln?"

No. Our first project in 2011 concerns the Behringer - our Great Hairy Leader's acoustic amplifier, not the Derringer (Booth's notorious weapon of choice).

People in the music world will recognise Behringer as the German manufacturer of a range of rather nice sounding kit, well priced but with a reputation for questionable build-quality. Although not heavily gigged, our Great Hairy Leader's Behringer amp was beginning to show signs of wear - busted buttons and sockets, etc. The Secret Laboratory agreed to assist with repairs.

Opening the Behringer uncovered a host of manufacturing peccadillos, the first being that none of the abundant case-screws appeared to serve any structural purpose. After removing all screws, the interior of the case remained resolutely inaccessible. It might as well have been carved from a single block of MDF. It became clear that gaining access would require more than just a screwdriver.

Above, our Great Hairy Leader gains entry to the Behringer using an electric jigsaw. The rather festive little circles in the photograph are due to the sawdust storm he raised in my living room, each particle caught in the flash.

The case thus breached, it was possible to remove all of the gubbins that needed attention.

Above, our Great Hairy Leader discovers the problem. Everything is made of crap.

We had to break there to order new components online and steady our nerves with a flagon of cider. Remember to tune in to the next thrilling episode of "Modding the Behringer" later this month.