Humpty Dumpty sat on a wall…
Humpty Dumpty had a great fall…
…and so the great nursery rhyme goes! But here at Oscilloclock labs, we’re not talking about an egg (which, one theory goes, represented the defeated King Richard III). We’re talking about a beautiful old CRT, savagely shaken and shattered during international shipping. What a waste. But oh, what a great chance to see the insides close-up!
This broken CRT missed its chance to live again in a nice VectorClock
Looking down the barrel. Imagine you are a phosphor molecule, with projectiles from this gun hitting you at the speed of light!
What do you do on a mundane business trip to London?
Why, shopping, of course! But if you were the humble proprietor of Oscilloclock.com, you would do much more than that… You would seek to expand your vintage electronic empire!
And so it was that I found myself hunting old electronic devices on Portobello Road one fine Saturday morning. Unfortunately, the game there was far and few between; only two relatively mediocre valve radios, in even more mediocre shape, at far more than mediocre prices…
Fortunately, my colleague was going to save the day. “Pop out to Cambridge for a visit – I’ve seen a few antique shops here,” said he. And after the hour train journey and a wee but of walking, we stumbled onto a veritable gold mine – Robbie’s.
Television broadcasting has switched from analog to digital – and if you’ve got a nice HD TV, you’ll be loving it!
But with that transition came the death of an entire breed of equipment – the Vectorscope.
Just to be clear, these are not monitors for playing ancient video games using vector graphics!! No, the Vectorscope is (was) used to give a delightful view of the ‘vectors’ inside an NTSC or PAL video signal, describing the color components of the signal.
If you were lucky enough to be a TV broadcast technician, you’d use your Vectorscope all the time to check your vectors’ amplitudes and phase. You would even give your vectors names like ‘Jack’ and ‘Jill’, and check up on their relationships daily, just as any responsible guardian would!
But above all, you would marvel every single day at the beautiful hardware you were using, and the complex circuitry involved. Take a look at my Tektronix 526 Vectorscope, which has oodles of delicious tubes to heat my shop on a nice winter’s day:
Well, it all went digital and there is no longer any need for analog color signal analysis. But dry your tears… There is something even better:
Announcing the Tek 520A VectorClock
This lovely Oscilloclock reincarnation of a Tektronix 520A, sold at Maker Faire Tokyo 2013, allows its new owner to forever relive the magic of NTSC, PAL and SECAM analog color.
Tektronix 520A VectorClock – brilliant blend of the old and new!
The Tektronix 520A has a stunning built-in array of lights for illuminating the CRT graticules. By simply removing the bezel and external graticule, the Tek 520A morphs into a deliciously moody timepiece!
Normally, I shun CRTs with built-in graticules. Their lines detract dreadfully from an Oscilloclock image. But here! The Tek 520A’s internal vectorscope graticule is round! What better way to accentuate a Circle Graphics driven display?
The Tek 520A is solid-state. It can be left on 24 hours a day and not fail for many years. This makes it a perfect match for my Maximum Re-use + Minimum Invasion policy: nearly all existing circuits – HV power supply, deflection amplifiers, blanking – are put to use, with just a few (reversible) tweaks.
The Oscilloclock Power Board is mounted neatly next to its own dedicated low voltage supply. A small relay board can be seen below, for controlling the Tek’s main power unit. All cabling is HV-tolerant and neatly fastened with high-temperature cable ties.
Of the more interesting reversible ‘tweaks’ needed for this retrofit, here we see a delightful little trimpot pretending to be a transistor. Quite an act, I would say!
Like what you see?
If you love big, looming Vectorscopes and need to have one put to good use in your living room, Contact me. And be sure to subscribe from the front page, to track all the other exotic experiments and unique timepieces targeted for 2014!
Credits to [Quinn] in Canada, for providing the initial inspiration for the Tek 520A VectorClock project!
One of the most exciting things you can do with a Scope Clock is to simply look at it from behind! In many CRTs, the anode coating (a conductive black surface sprayed onto the inside of the glass) doesn’t extend all the way to the screen – leaving a nice gap of clear glass from which to observe the beautiful electron beam.
Ha – you can put down your magnifying glasses now.
This site is dedicated to showcasing my Scope Clock designs, and to sharing technical information openly to anyone interested in these vintage electronic timepieces.
What is an “(Oscillo)scope Clock”?
A unique style of clock that displays the time (and other fun things) on a CRT taken from an old oscilloscope. These clocks operate on a fusion of old and new electronics, and are often housed in beautifully crafted cases of wood, metal, or acrylic.