• Very Good At VGA

    Very Good At VGA

    Recently, [Justin] asked: Can his beautiful Tektronix 606 XY monitor be made to work as a computer display?

    And even more recently, [TJ] explained he has a plethora of Tektronix devices, and asked how he might put them to use…

    So lovely… but what can you DO with it?

    Well, “putting to use” is precisely what we do here at Oscilloclock! And one option, indeed, is to hook the target device up to a modern-day PC and use it as a computer monitor.

    Time for an update on the Oscilloclock VGA Core and its variants!

    Shades of Grey Green

    Avid readers may recall these previous posts about making SVGA and XVGA displays from vintage oscilloscope CRTs:

    VGA display… On a 3″ scope tube!
    The VGA Cube!
    New Year’s Resolution!

    Truly dedicated readers may even recall that the solutions presented drive the CRT directly, completely bypassing any internal circuitry of the host device. And, that there were limitations in the current design; the most serious being binary blanking, where the beam is switched either on or off. There were no shades of grey.

    This Running Man needs no shades!

    Inspired by [Justin], we experimented connecting the Oscilloclock VGA Bare (a barebones VGA interface board) to our lab’s Tektronix 620 XY monitor. This bad boy has an analog Z axis (intensity) input, meaning that we can theoretically have shades of grey… er, green.

    And the result? A pretty decent PC display!

    A recent post, as displayed on the Tektronix 620. (Yes – I know it’s upside down)
    Here’s what it looked like on the laptop’s display

    Doomy Demo

    Ever wanted to play classic Doom on an old green screen? Here we go!

    This Tek 620 is no longer doomed – it’s been Doomed!

    Yes – the display is horizontally inverted. The VGA Bare currently does not support flipping the X and Y signals.

    This unintended challenge makes playing Doom exceptionally difficult!

    Matrix Masterpiece

    Who could resist displaying digital rain (Matrix code) on an old Tek display?

    Matrix code, as generated by tmatrix. Note it’s horizontally inverted

    While working on this demo, I learned more about Matrix code – and that it includes Japanese characters scanned from the creator’s wife’s cookbook. Wow, I thought those raindrops looked awfully familiar!

    The Setup

    Not a bad result! And the hardware setup was simple.

    • PC
    • HDMI to VGA adapter cable
    • Oscilloclock VGA Bare
    • BNC cables and connectors
    • A few resistors
    • Power pack

    As always, nothing is perfect! A few tricks were needed to make the experiment a success:

    1. The VGA Bare circuit needed a few minor improvements, to better support official SVGA and XVGA timing standards
    2. A crude level adjuster (resistive divider network) was needed between the analog intensity output and the Tek’s Z axis input
    3. The PC display resolution needed to be set to SVGA (800 x 600) or XVGA (1024 x 768), to give maximum clarity
    4. A high-contrast theme was selected, to greatly improve display contrast

    What’s next?

    With the successful close of this proof-of-concept, [Justin] and [TJ] now have another clear option to make use of their vintage test equipment: a VGA Bare ready to mount inside their device, or a beautifully encased VGA Connect (à la Oscilloclock Connect).

    But to make this truly production-worthy, a few improvements are needed:

    1. Output voltage level adjustments, fully independent for X, Y, Z
    2. A higher-voltage Z amplifier
    3. Independently invertable X and Y signals
    4. Reduction in the ‘ghosting’ or ‘ringing’ effects currently observed
    5. Improved contrast and avoidance of ‘washout’ seen between pixels
    6. Digital HDMI input !

    … all added to Oscilloclock’s ever-growing backlog of things to do!


    Do you want to play your favourite classic game on your old XY monitor? Do you want to stack 10 oscilloscopes on your shelf and have them all showing Matrix code? Or put your Grandpa’s old scope on your desk at work and have it display your Outlook calendar?

    Our mantra makes it possible: Just. Because. We. Can.

  • Heavenly Harnesses

    Heavenly Harnesses

    A modern military-spec connector from France meets an ancient Bakelite connector from Japan. It’s love at first sight! The two are joined together in eternal conductivity. Not by a priest, but by eleven 3kV silicon wires surrounded in a lustrous braided sheath…

    … Or so goes the story. There are other accounts, but we like this one best!

    Diversity and distinction

    Serious readers will have recognized the above harness, as it was used in Exo series Oscilloclocks such as the recently featured Exo 3KP1.

    The Exo series. CRT and Control Unit must mate!
    … and this is how it’s done.

    The Gold standard

    We’ve crafted all kinds of harnesses for other Oscilloclock models. This one below takes the cake! Check out the chrome connectors, gold-plated pins, IP68 compliant clamps, and fray-resistant sheathing.

    Model 1-S ultimately extravagant cable
    The ultimate in extravagant cabling! Why not?
    As used in the stunning Model 1-S

    Simple and functional

    Coming back down to earth, we have a less extravagant, highly functional connectivity solution for the Model 1 series:

    No gold or chrome. But still military-spec and very solid. A joy to plug and unplug!
    … As used in this Model 1 130BXB31

    Crazy cabling

    NO single Oscilloclock used more cabling than the infamous AfterShock Clock! This consisted of two complete Oscilloclock Core sets integrated together to drive a dual-gun CRT.

    The AfterShock Clock in its initial form. Have you ever seen so many cables?

    The harnesses supplied in this first delivery were… raw, to say the least.

    Later, as [Atif] worked on his AfterShock Clock’s case, he ordered a set of production quality cabling: two CRT harnesses, and one custom interconnect cable to join the two control units together. Beautiful!

    Fixated on the affixed

    At another point on the spectrum of craziness are harnesses that are not fully removable. Below we have the incredible OscilloBlock Summer Dusk Edition, where the cabling enters the Lego-built Control Unit via a grommet:

    There are more designs to show. But let’s move on to an important topic!

    A safety consideration

    Some Oscilloclocks, especially those in the Exo series, are designed to physically expose the CRT as much as possible to the happy owner and his/her entourage of vintage electronic aficionados. They can touch. Feel. And even listen. (Yes! Some CRT electrodes can even emanate sound!)

    An Exo 3KP1 needs 2.2kV to draw this!

    But many readers may also know that cathode ray tubes operate at high voltages. In fact, in the baseline Exo 3KP1, some pins of the CRT are supplied with roughly 2,200 volts compared to other pins.

    Now, clever readers may have noticed in photos of the assembled Exo 3KP1 that there is a slight gap between the socket and the base of the CRT. The metal pins are slightly exposed. If someone or something somehow bridged that gap – with prying fingers, paws, coffee, or dust – the results could be serious.

    Never fear! There is an insulating o-ring (gasket) that was not installed at the time the Exo photos were taken. It’s a very basic but effective solution. See these instructions from the Operating Manual:

    Installing the ubiquitous o-ring

    We don’t have enough hours in the day to talk through all the safety considerations. But they include:

    • usage of high voltage tolerant silicon-sheathed wires
    • selection of military-spec connectors rated for high-voltage use\
    • a clever pin layout that minimizes the voltage difference between any given pin and its neighbors

    We’re proud of our harnesses. And you can be too.


    And that’s a wrap!

    Are YOU haplessly hooked on harnesses? Does capably-crafted cabling captivate you? Stay tuned! Next time we craft up a CRT harness, we’ll snap a few photos along the way. It’s a surprisingly deep topic!

  • Exo 3KP1

    Exo 3KP1

    Huh? R2D2’s cousin? C3PO’s sister?

    No! We’re not here to talk about a new Star Wars character! The 3KP1 is a type of cathode-ray tube that was used in many low-cost 1960s-1970s Japanese oscilloscopes.

    And the Exo is a series in our Oscilloclock range that fully exposes the CRT both visually and physically, much to the delight of the owner and visitors – while of course protecting high voltage areas from dust and prying fingers.

    The Exo 3KP1!

    First crafted for [Jerry] back in 2019, the Oscilloclock Exo 3KP1 is the default character in the Exo series, alongside the arguably oddball Oscilloblock – Summer Dusk Edition and the slightly more exotic OscilloTerm Exo B7S4.

    There’s nothing more soothing than the green glow of flourescent phosphor backed by the amber ambience of the CRT heater. Ahhh, that’s nice.

    This Exo shipped with all the “standard” screens, like the analog clock face below. But why stop there? We’ve done custom logos, movie themed features, oddball time systems, and so much more!

    From the top, [Jerry] and his dinner guests can readily inspect every square centimeter of the CRT and its exquisite innards. Cooool.

    Inside the unit, neatly tied cabling lends an air of gentle sophistication, while the green of the circuit boards harmonizes well with the phosphor.

    Even as a baseline model in the series, the Exo 3KP1 is distinctly attractive.

    [Jerry] did make some choices along the way, including which CRT to use. Let’s explore his CRT options in more detail!

    Round vs. flat

    As shown in the photos, the CRT that [Jerry] selected has a slightly convex face. This was the standard shape of the original 3KP1 type CRT, and is a perfect choice for the Exo case style, as it visually softens the glass edge exposed in front of the acrylic ring supports.

    The round-faced 3KP1 was superseded after some years on the market, by a flat-faced version: the 3KP1(F). This version is rather more commonly found and they are delightful to use. We used a 3KP1(F) in the Exo series Oscilloblock, as shown at right.

    Which would YOU prefer – round or flat?

    Phosphors and flavours

    [Jerry] had another choice to make: the phosphor! While the standard phosphor of most CRTs of the day was green, other colours were available such as amber, blue, white, purple. Such CRTs are more rare, but we have some… and so could Jerry!

    The “trailing effect” on a long-persistence CRT

    There were also varieties of CRT with different persistences; i.e., how long the trace would continue to show on the screen! We love this shot of the moving second hand on a blue, long-persistence CRT:

    And, we just happened to have a 3KP7 CRT in stock with exactly these characteristics.

    But in the end, [Jerry] wanted the nostalgic look of an old green-screen computer monitor, and chose the stock-standard 3KP1.

    Nice choice!!

    The longevity question

    [Jerry]’s clock shipped with a used 3KP1 CRT. Pre-owned, pre-loved, and pre-21st century.

    But we don’t sell junk. [Jerry]’s CRT was selected for its unblemished phosphor, and for its still-bright and vibrant performance. And, of course, there is the standard warranty of 1 month for a used CRT:

    But the question often comes: “How long will a CRT really last?”

    Here at Oscilloclock we don’t mince words, and we don’t use euphemisms (much!). But the fact is this – after 15 years of crafting Oscilloclocks for customers around the globe, no-one has reported having to change their CRT. Maybe it’s happened and we are oblivious. Even better!

    Our secrets to CRT longevity are:

    1. We select only the highest quality CRTs, made by reputable manufacturers. [Jerry]’s CRT was manufactured by Toshiba, a key supplier of the day.
    2. We check CRT specifications carefully, and avoid those with any hint of short lifetimes. (Some CRTs had very short expectancies, such as 1000 hours! Perhaps these were used for demanding applications where even a tiny degradation in performance could not be accepted.)
    3. Oscilloclocks employ multiple mechanisms to avoid screen burn-in (phosphor burn).
    4. Oscilloclocks employ a soft-start mechanism to minimize stress on the CRT heater.

    The Spare

    Notwithstanding our facts around longevity, [Jerry] decided to plan ahead for an eventual CRT replacement. He purchased a stunning new-old-stock Hitachi 3KP1, with quality certificate and even in its original box.

    They don’t get more original than this!

    But is a Hitachi 3KP1 better than a Toshiba 3KP1?

    We’ve compared them, and couldn’t tell any difference in performance or characteristics. We did notice one thing, though: the Hitachi is significantly heavier than the Toshiba. Hmmm….

    One day, we’ll dissect some (defunct) units, and get to the bottom of that odd observation. Stay tuned for a post!


    Like what you see? [Jerry] did. Check out our other creations!

  • X-ray Xcitement

    Some time ago, [javadesigner] asked something that no doubt many of you have been wondering: Do Oscilloclocks emit radiation?

    Had a question about oscilloscopes – specifically cathode-ray tubes (CRTs). X-rays etc were discovered in similar tubes, and I’ve read that high kV tubes produce both beta and X-ray radiation.

    … Have you ever measured x-ray emissivity with CRTs, and if so, are there any mitigation strategies – especially for X-rays? Leaded glass enclosures, etc.?

    Great question!

    Will your faithful Oscilloclock do this to you?
    CRT used in this demo: 130BFB31

    Fortunately the answer is a clear NO. Our hand-crafted Oscilloclocks do not emit dangerous radiation.

    The general rule of thumb with CRTs (in fact, any electrical equipment operated in a vacuum) is that X-ray emission is negligible at anode voltages less than around 10kV. The accelerated electron beam simple does not have enough energy to generate X-rays when striking the phosphor screen.

    But above 10kV, X-rays can and are produced as a result of the higher-energy bombardment. The high-voltage CRTs used in television and computer monitors of the day always incorporated lead glass (strontium-barium glass), to block these X-rays. (And… to protect against implosion!)

    In any case, all Oscilloclocks operate at voltages well below 10kV, so this does not become an issue.

    A few of the CRTs in stock - 6498, D4P, 3WP1, 50SB1, CV2302. None emit X-rays!
    Just a few of our CRTs in stock – and none of them emit X-rays!

    Thats right – whether we craft your custom timepiece from a behemoth 6498 (at left, operating at 6 kilovolts), a delightful D4P (3kV), a sleek 3WP1 (1.5kV), a cute 50SB1 (1kV) or an eentsy-weentsy CV2302 (500V), you’ll be illuminated but never irradiated.


    Fascinated by electron beams and phosphor bombardment? Do you have a question that everyone else wants to ask? Query away, we love Q&A!

  • Right on Time…

    Oscilloclocks keep time indefinitely, without needing any adjustment…

    Such unique time displays… and they’re accurate!

    How?

    By automatically synchronising time against a reliable external time source, at regular intervals.

    The current standard synchronisation sources are GPS satellites (via either onboard or external receivers), or NTP servers (via WiFi).

    The Oscilloclock Wave – a WiFi dongle to pull time (and other things) from the Internet

    And for the most decadant timepiece, there is an even cooler option: a rubidium time source. You can gain/lose at most 2 milliseconds per year!

    Even an Atomic Oscilloclock is an option.
    Because We Can.

    But let’s take a more in-depth look at the two standard options:

    GPS – stand-alone & reliable

    Yes, that’s right – you can get extremely accurate time from GPS satellites!

    The long-standing favourite amongst Oscilloclock aficionados is the External GPS (Garmin ‘puck’) option. Features include:

    • a long cable that allows positioning for best sensitivity
    • an inbuilt magnet for attaching to metal beams
    • a gorgeous connection system – satisfying haptics and robust locking

    Of course, we also have the internal GPS option, where the GPS receiver is mounted on the Control Board itself. This is super nifty, if there is no concern about satellite signal strength where the clock is placed. (This is very rarely an issue. These receivers are extremely sensitive!)

    Can you spot the onboard GPS module in this gorgeous OscilloBlock?

    Geolocation

    The GPS option allows the Oscilloclock to obtain not just time, but also geolocation information from satellites.

    Okay, it’s true that Oscilloclocks are generally placed in a fixed location, so showing the clock’s location on a map might not be very useful…

    Think again!

    How about an OscilloGlobe, to warm up your long-distance relationship? Plot you and your friend’s Oscilloclocks on a spinning globe, and count down the hours til you meet again…

    A delightful Heathkit SB-610 shows another Oscilloclock, live and ticking elsewhere in the world!
    (Want a closeup of this demo feature? See this video)

    Or perhaps you fancy an OscilloWear? A wearable Oscilloclock, sporting a miniature CRT and it’s-only-possible-in-Japan miniaturised circuitry! Complete with GPS.

    An OscilloWatch capable of recording your sporting activities? With OscilloMaps that guide you to the nearest Oscilloclock retailer? And of course: the OscilloPhone, or oPhone for short?

    Ahh, we could have so much fun making devices that use location data…!


    Want even more info on the GPS hardware option? We have a nice support page here: Garmin 18x GPS Puck.

    NTP – low-cost & extensible

    The Oscilloclock Wave is the glorious device that allows your Oscilloclock to connect to a Wi-Fi router and pull in time from NTP (Network Time Protocol) servers.

    It comes in different forms, both external and internal:

    The Oscilloclock Wave requires a WiFi connection (and Internet), and some initial configuration – it doesn’t just work straight out of the box, in a standalone way like the GPS option.

    However, the Wave has a distinct advantage: it can access various APIs (think: providers of data over the Internet) to pull in and display all kinds of information!

    Want to display the current weather on Mars? The latest news? Stock prices ticking madly? All this is technically possible… and can be implemented upon request.

    To date, we’ve used this capability in several themed Oscilloclocks: the Astro Clock (pulling in sidereal time from an API) and the AfterShock Clock (pulling in earthquake data).

    Sidereal time, for all the astronomers out there!
    Earthquakes are disasters – no joke. But a semi-live visualization in Lissajous figures? Too cool..

    Not saturated yet? For more on Wifi based synchronisation and various configuration options, see the support page: Oscilloclock Wave.

    The No Synchronization option!

    Do you want to take your Oscilloclock off-grid? We’ll craft you a unique clock powered by wind, solar, USB-C power bank, or even a hamster wheel. (We can even procure extremely low-power CRTs!) But to go fully off-grid, you won’t want to use GPS or WiFi.

    A (more likely!) scenario is simply that signal strength is just too poor. Maybe your clock sits in a basement 3 stories below ground…

    For such cases, you can set the time manually in the Time Setting screen. Once set, an on-board quartz oscillator then maintains reasonably good time (in the order of seconds per month). You’ll want to adjust it occasionally!

    Manual time configuration screen on the Tek 520 VectorClock

    Decisions, decisions…

    Must it be one OR the other? Can’t a gadget lover have their Oscilloclock source data of different types from both GPS and public APIs over the Internet?

    Sadly, no – not in the current Control Board revision. This supports only a single interface, which is occupied by either the GPS or the Wave module. (We have multiple input capability on the long to-do list!)


    Oscilloclocks are beautiful and entertaining. There’s that warmth of the CRT filament and the brilliance of coloured phosphor excitation, combined with all the features of our digital era.

    But above all – they are clocks! Hope you enjoyed this treatise on how time is managed.

    If you’re up for the craziness of an Atomic Oscilloclock, or if you want a custom theme using specific API data, let me know! Otherwise, stay tuned!