Tag: Scope Clock

  • The Secrets to Long Life

    It’s a sobering thought, and not a particularly pleasant one, that your Oscilloclock might just outlive you

    But let’s not dwell on such talk! The real focus today is the oft-asked question: “How long will my Oscilloclock last?”

    The honest answer is: we don’t know.

    However, we do know how we try to maximize longevity, and we do have repair and return statistics from 15 years of delivering beautiful Oscilloclocks. We’ll go through all of this with you!

    Your Oscilloclock

    There are many different models and styles of Oscilloclocks (see the Gallery), with infinite variations in terms of parts that make up the final product.

    But in terms of longevity, we can broadly categorize components like this:

    • CRT – the cathode-ray tube display
    • Hardware – the case, mounting supports, thermal parts, nuts and bolts
    • Oscilloclock boards – the electronics designed and built right here in the Oscilloclock lab
    • Original device circuitry – the host device’s original electronics that are kept in use (if any)
    • Harnesses and cabling – wires, plugs and sockets; both internal and external

    In today’s post, we’ll tackle the proverbial elephant in the room – the CRT!

    Your CRT

    Your clock’s cathode-ray tube is actually a type of vacuum tube. There is a glass enclosure, with a screen coated with chemical phosphor. It has a heater (or filament), and other electrodes made of special materials. These are welded to wires that are soldered to pins protruding through airtight seals in the glass.

    Each italicized word adds up to this: A CRT is quite fragile!

    The CRT – easily the most delicate part of any Oscilloclock!

    CRTs have many “failure modes” – and we’ve seen them all! Let’s explore.

    Failure mode A: Natural causes

    Vacuum tubes (or valves) rely on thermionic emission. Electrons are emitted from one of the electrodes called the cathode, when it is heated up and voltage is applied.

    In a CRT, thermionic emission is used to create the all-important electron beam

    In any vacuum tube, this emission capability decreases over long periods of active use. This is most commonly due to a degradation of the special emissive material and coatings that are used in the cathode.

    Your Oscilloclock’s beautiful CRT will face the same issue eventually. As the number of electrons bombarding the phosphor screen decreases, the image will gradually get dimmer and dimmer, until eventually it cannot be seen.

    How long will a new, unused CRT last before it succumbs? Well, manufacturers quote working lifespans of tens of thousands of hours of active use (heated and voltage applied). This equates to a few years.

    We want our Oscilloclock CRTs to last decades, not years! So what do we do?

    Secret 1: Auto Power Off

    Strongly recommended by Oscilloclock labs, this feature simply turns the Oscilloclock off after a period of non-activity (not touching the control). Alternatively, owners can set a specific “Off at:” time.

    It may sound counter-intuitive, but in practice, all Oscilloclock owners to date have been comfortable to turn their unit on just when they intend to enjoy it, and allow it to switch itself off.

    For clocks that are permanent fixtures in offices and restaurants, staff manually turn their clocks on together with other appliances in the premises, and set them to turn off at the business closing time.

    Secret 2: CRT type and manufacturer selection

    While working with the owner to choose their CRT, we emphatically avoid tubes where the manufacturer quotes short lifetime ratings.

    Sadly, some CRTs that are most readily available today fall into this category. See the data sheet below, specifying an incredibly short maximum longevity of just thousands of hours!

    Q. What can be done for a CRT ‘on its last legs’?

    Sadly, it isn’t feasible to restore a dead CRT to factory condition. But there are two things that can be done before it reaches that state, to prolong the inevitable:

    Firstly, Oscilloclock owners can adjust the Intensity control, as described in the Operation Guide. This will drive the CRT harder and brighten the image.

    Secondly, here in the Oscilloclock lab, we can attempt a CRT rejuvenation. This procedure involves carefully applying higher-than-normal voltages to the heater, and between certain electrodes. Done correctly, this can ‘peel back’ a thin layer of the cathode surface that has degraded or suffered from ‘cathode poisoning’, to reveal a more emissive layer of material beneath.

    Q. Will a new (unused) CRT last longer than a used one?

    Theoretically, yes.

    BUT in all our experience at Oscilloclock.com, we see no evidence that new-old-stock CRTs last any longer than used ones.

    Why is that? Well, most CRTs we use are harvested from laboratory test equipment. Most operators typically switch lab equipment on only when needed – so the accumulated operating time is often very short.

    In fact, we openly encourage the owners to choose a pre-loved tube! We vet all our CRTs, testing them electrically and inspecting for any damage to heater, phosphor, glassware, or seals. No electrode is unturned; no emission-impacting detail is omitted!

    Failure mode B: Humpty Dumpty

    Humpty Dumpty sat on a wall…
    Humpty Dumpty had a great fall…

    Visit A Humpty Dumpty CRT for a truly woeful tale…

    If the CRT glass is cracked or broken, there will be rapid loss of vacuum inside, halting all electron emission. If voltage is applied, the heater will quickly burn out, due to oxidation.

    All the king’s horses and all the king’s men,
    Couldn’t put Humpty together again.

    Sadly, several CRTs have arrived at our lab in this woeful state.

    Secret 3: Shipping precautions

    We take great pains to ensure that Oscilloclock owners do not experience a Humpty Dumpty episode.

    • CRT mounting – in all Oscilloclock models we ensure the CRT is mounted with sufficient cushioning (silicon or rubber) against its mechanical supports.
    • Double-boxing – all separable components of an Oscilloclock are individually boxed prior to packing into a larger box for shipping.
    • Packing material – we use a combination of bubble wrap, foam peas, and Styrofoam to cushion the internal boxes and their contents.
    • Box selection – we love to recycle, and we have loads of used boxes on hand. We pick the stronger ones and make sure they are the right size – large enough to fit cushioning material, but never so large that the inner boxes might slide around!
    • Carrier – we have had extremely good results with the standard EMS service available from Japan Post, and this is what we always recommend.
    • Insurance – we always insure the shipment to a sufficient value.

    Thanks to this secret, to date we have only had one case of breakage for an item shipped out from our lab! And even then, the insurance claims process working with Japan Post was quite straightforward – if not even pleasant.

    Failure mode C: Gassy CRT

    No, CRTs can’t eat too many potatoes! But CRTs definitely do not like air.

    A CRT may become “gassy” if too much air leaks in via the pin seals or a fracture in the glass, such that its internal self-healing mechanism (formed by the getter electrode) is overwhelmed.

    On a gassy CRT, the image will become dimmer and dimmer until it disappears entirely.

    While there is no true remedy for this malaise, an owner can postpone the inevitable by adjusting the Intensity control. And in rare cases, the CRT rejuvenation procedure described earlier may stimulate the getter electrode to mop up some of the excess gas.

    Secret 4: Avoid potatoes mechanical shock

    Gassy CRTs crop up occasionally, usually as a result of excessive mechanical stress or shock.

    Besides shipping precautions (Secret 4), we are even careful when storing CRTs. Being situated in the Japanese archipelago, the Oscilloclock lab and all its contents must endure significant earthquakes occasionally.

    We therefore place the most precious CRTs in strongholds – small cavities in the woodwork that suffer less shaking and are very unlikely to collapse (even if the rest of the lab does). Touch wood!

    Failure mode D: Phosphor burn

    Roughly 10% of the CRTs we harvest exhibit a permanent scar, prominently visible to the naked eye…

    Phosphor burn – it looks ‘on’ even when it’s off!

    To understand why this occurs, first think of an iron burn. If you deliver too much heat for too long into the same spot, your nice new Oscilloclock brand T-shirt will feature a prominent (and permanent) mark as shown below.

    Iron burn – this shirt’s fibres have been literally scorched!

    In a CRT, a beam of fast-moving electrons bombards the phosphor coating on the screen to produce an image. If the beam is too intense, or it is allowed to trace the same route on the screen over a long period of time, the phosphor compound may degrade and lose its luminance. The result:

    • The screen won’t light up well in those spots any longer.
    • The damaged areas may appear dark even with the power off – a ‘ghost image’.

    Devastatingly, it just isn’t possible to restore the phosphor. But since these CRTs are otherwise perfectly healthy, we put them to good use in the lab for testing and experiments.

    Secret 5: Choose a decent CRT

    Some CRT types and brands are more susceptible to screen burn-in than others. Some factors include:

    • The factory list price (you do get what you pay for)
    • The manufacturer’s credit rating for reliability
    • The phosphor compound used
    • The thickness of the phosphor coating
    • Any additional technology; e.g. aluminized screens

    For more details, see our deep-dive post: Burn-in? Nope!

    Secret 6: Screen-savers and other protection mechanisms

    Remember the phrase “screen saver”? In the pre-LCD monitor days, most computers employed some form of software that would stop the same image being displayed for too long, to avoid screen burn-in.

    In addition to Secret 1 (Auto power off), Oscilloclocks have several more screen-saving features that protect the phosphor:

    • Hourly XY Bump – shifts the image by a small amount in the X and Y directions every hour
    • Auto screen switch – cycles through the screens (clock faces) at regular intervals
    • Bright/dim control – switches between preset beam intensities via a front-panel control (on some models)
    • Intensity control – manually adjust beam intensity if required to suit darker rooms

    For more details, see our deep-dive post: Burn-in? Nope!

    Failure mode E: Disconnected electrode

    Very rarely, the weld between an electrode and its connecting wire fails. Or the soldered joint between the wire and the external pin fails.

    The symptoms depend on which electrode has been disconnected, but one thing is for sure: the CRT becomes defunct. How awfully sad.

    Secret 7: Cry and move on…

    I would like to simply write, “Choose a reliable manufacturer.” However, they don’t get much more reliable than Tektronix!

    Besides protecting the CRT from mechanical shock (see previous Secrets), all we can do is accept fate…

    Failure mode F: Open heater

    A CRT heater (filament), just visible

    Remember incandescent light bulbs of yore, with a delicate filament wire suspended inside the glass? They burned out over time – typically with a break in the wire that you could even see with the naked eye!

    Well, the heater in a CRT is also formed from filament wire (albeit with different metals designed to emit more heat than light). If a CRT heater burns out, the cathode cannot be heated sufficiently to emit electrons, and the tube is rendered useless. A sad, sad state of affairs…

    But what causes such failure?

    Well, when did light bulbs typically fail? Yes! Right when you switched them on!

    The reason is that a cold filament has a very low resistance. When you apply voltage, a huge amount of current flows (called inrush current). This settles as the heater warms, but the initial power and sudden temperature change causes metal fatigue. And after many switch-on cycles, the wire can break.

    Secret 8: Soft-start!

    The best way to preserve the heater is to limit the inrush current, so that the filament can warm up gradually. Every Oscilloclock employs one of the following 3 types of inrush current limiter:

    1. The sacrificial lamb – a light bulb!

    In this scheme, we simply place a specially-selected incandescent light bulb in series with the CRT heater. Upon switch-on, most of the supply voltage is applied to the light bulb’s filament (because the CRT heater’s resistance is low), making it light up brightly.

    Primitive. Low-cost. Yet immensely effective!

    As the CRT heater gradually warms up, its resistance increases. The voltage across the light bulb decreases, making it dim and cool down, and its resistance lowers. By this time, the CRT has fully warmed up and stabilized, with most of the voltage now shifted to the CRT heater.

    Functional, AND beautiful to watch! Besides the Exo in the video, we’ve used it in the Heathkit OR-1 Oscilloclock and a few other custom pieces.

    2. Mister thermistor

    These long-legged beauties are called thermistors. They have an odd characteristic called NTC (negative-temperature-coefficient). The hotter they get, the less their resistance!

    Does that sound familiar? Yes! They can replace the light bulb used in method (1) above. Most of our Oscilloclocks employ these devices, because they are reliable, predictable, and very small.

    Nonetheless, we enjoy the switch-on supernova of the old-fashioned light bulb. And some owners do, too!

    3. Electronic soft start

    Both light bulbs and thermistors are passive devices; their resistance vs. temperature profile is known (and can be charted in a specifications sheet). BUT they are not aware. They don’t have any kind of feedback loop, so they don’t actively control the voltage across the CRT.

    Recent Oscilloclock Power Board designs provide an active soft-start option. This is a circuit that dynamically ramps the output voltage up from 0V to the final voltage in a preconfigured number of seconds.

    Effective and reliable, but just a little more complex!

    Q. Will running the heater at a lower voltage prolong the CRT?

    No. According to many folks, running filaments at lower voltages than specified can accelerate “cathode poisoning” – degradation of the cathode material due to absorption or chemical reaction with trace foreign substances. We don’t recommend this.

    Q. “Sacrificial lamb” approach – won’t the light bulb itself die?

    Yes, eventually. However, it will certainly outlast the CRT filament. Although the light bulb filament does suffer a high inrush current, even a cold CRT presents a small resistance into the circuit. The voltage across the bulb at turn-on is therefore less than its rated voltage, and this extends its life.

    Q. Isn’t there something that can be done to restore a CRT heater?

    Maybe. Some folks have managed to ‘fuse’ a broken heater together, by injecting a very high voltage (thousands of volts) across the gap. The resulting arc effectively welds the broken filament. We haven’t yet had the pleasure of trying this, but if we do we will certainly write it up for you!


    Replacing the CRT

    Fact: In 15 years of crafting Oscilloclocks, not a single unit has ever come back for CRT replacement!

    That said, every CRT we shipped will reach its end of life. It’s just a matter of time.

    But don’t despair! Oscilloclock carries spares for most common tubes, and we can supply and replace them. Some owners even choose to purchase spare CRTs with their original order, so that they have them on hand.

    Q. What about rare CRTs?

    If a clock was crafted from a particularly rare CRT, there may be no spare available. But again – do not despair! We can work with the owner to select another type of CRT, and modify their precious device to suit. By rejuvenating their clock ‘with a twist’, the owner may experience even more of a thrill than if we simply restored it to its previous state!

    A rare CRT: type D4P. Don’t worry – we can replace it with something!

    Q. Can owners replace the CRT by themselves?

    We always recommend shipping clocks back to the lab for CRT replacement.

    However some models, especially those in the Oscilloclock Exo series, employ a simple and safe mechanism to swap CRTs – and we provide instructions in the Operation Guide for doing this.

    Q. Does Oscilloclock.com produce or repair CRTs?

    No. We dream of one day establishing a CRT factory. Or at least a CRT repair facility. However with all the toxic chemicals, high vacuum, glasswork, and intricate welding involved, this is likely to remain a dream.

    Q. Are new CRTs being manufactured anywhere in the world?

    Yes – some types of CRTs are being manufactured in some countries. However many are not suitable for Oscilloclocks. They may employ electromagnetic deflection (which we don’t yet support), they are special-purpose for military or aerospace applications (too expensive!), they are very cheaply-produced (not reliable), or they have short lifetimes per design and require frequent replacement.


    Swappable CRTs!

    Many of our ‘Full Package’ type clocks (see Gallery) support display swapping.

    Essentially, we craft complete additional display units, which the owner can swap in at will simply by swapping cables to the Control Unit. There is no need to open a case, touch the CRT itself, or any form of delicate operation.

    This is normally used to change the ‘mood’ of an Oscilloclock, by swapping in different phosphor colors. But it also can be used to more easily swap in a replacement CRT.



    Do you want long life, both for yourself and for your precious electronic devices? Are you tired of modern society’s throwaway culture, built-in obsolescence, and device non-serviceability? Our goal: electronic artwork that might be passed down a generation (or more) in actual working order!

    Stay tuned for Secrets Parte II, where we will explore the life of other components!

  • 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!

  • 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!

  • Made in Japan. Then. Now.

    Here at the Oscilloclock Lab, we see a lot of vintage Japanese oscilloscopes made in the 50’s to 70’s. Most were purely utilitarian and austere, with little aesthetic appeal.

    But this Toshiba ST-1612B is different. It’s cute, compact, and culture-rich. Just when we thought Toshiba had exhausted its artistic reserves with their stunning ST-1248D, they managed to come up with THIS. Wow…

    Oscilloclock’ed!

    We discovered our protagonist some years back – dirty, dusty, and destined for the trash heap. For aeons, it sat in stock, patiently waiting its turn.

    “Oh, when can I transcend test equipment mundaneness, and reach nirvana like my brethren?” screamed our protagonist.

    During our COVID-era hiatus, this unit’s pitiful wail fell on deaf ears. But with a strong recent recovery in parts availability, shipping routes, and other stabilizing factors, the Oscilloclock Lab has begun to thaw. Spring has arrived!

    And what better way to mark the occasion than to grant our Toshiba its wish?

    Done.

    And yes – it was made in Japan. Again.

    Exquisite exterior

    The case and knobs were in reasonably good condition and polished up very nicely…

    One knob is NOT original. Can you pick it?
    Class and style – even down to the model number plate at rear!

    Sadly, the leather carrying strap had seen better days. Yes, you read that correctly! This was designated as a portable oscilloscope, although it weighed in at more than 10kg, and had no battery supply!

    Nice leather. But was it really… portable?

    We love this adorable hatch compartment and secret patch panel. So utilitarian! Whole tribes of radio servicemen must have stashed their valuables here for safe keeping, before going away on holiday. Sadly, there was no jewellery or secret documents to be found in our unit…

    Take a look at this CRT hood. The phosphor screens in cathode-ray tubes are sensitive to external light, so many ‘scopes employed hoods or shades to keep ambient light out. This improves screen contrast for the lucky operator. Kudos to you if you can recognise the material used our Toshiba’s hood:

    Yes, it’s rubber. Solid rubber, with no metal tube inside. And while it’s a little banged up on the surface, it’s not disintegrating or brittle! It’s firm, yet still sufficiently flexible to support the CRT. And a little plastic polish did wonders. Good for another 60 years!

    Incredible internals

    Unlike many other scopes of the era, opening the case is easy. Just turn the latches with a coin, a single revolution. Voila!

    A nice complement of 12 tubes. Toshiba made them accessible for easy replacement

    As with its Toshiba brother and several other units crafted to date, we carefully installed amber LED lighting to simulate the original warm, gentle glow of electron tubes. This generates a beautiful, peaceful ambience.

    XY Input inspires!

    Avid readers may recall the XY Input feature first introduced in the Metropolis Clock, and included in several models since.

    This ST-1612B unit features a neat set of banana jacks in the rear hatch compartment, where the oscilloscope probes used to plug in. We repurposed them as X and Y channel signal input connectors.

    Driven by function generators, preamps, or even a mobile phone, we can explore an entirely different level of visual imagery!

    A function generator app
    A scene from “Planets” by Jerobeam Fenderson, played on the Toshiba

    A just-fit retrofit

    The ST-1612B was an engineering marvel. They packed an amazing amount of circuitry into a very limited space.

    But we needed to find space for two 100 x 80mm Oscilloclock boards. With legroom to isolate high voltage and provide circulation. And where controls can be reached. Not easy!

    Well, removing just a few bits and pieces* revealed two nice big cavities. And the best part? There were already access panels, complete with ventilation holes! What foresight those Toshiba designers had!

    In situ adjustments, made easy

    Control Freak

    You can’t beat vintage test equipment if you like controls: toggle switches, slide switches, rotary switches, potentiometers, trimpots – these guys have it all!

    But at Oscilloclock.com we target simplicity. There is only one control you need to turn the clock on and off, change faces, change settings, and generally play with your precious. Here, the focus control (焦点) gives you this authority. Who would ever guess?

    And for that most discerning owner, keen to install her beloved Toshiba ST-1612B in a moody environment such as a bar counter, living room, or bedroom: the intensity control (輝度) dictates the velocity of the electrons, as they smash haplessly into the phosphor. Okay, okay – it’s just a brightness control!

    Finally: we’ve wired up the frequency range switch (周波数範囲) to switch something on and off. We haven’t decided what. Let the Toshiba’s future owner decide its fate!

    What does this DO? You decide!

    Circle Graphics – with a caveat

    Oscilloclocks employ Lissajous figures to generate smooth, curvy artwork and characters on the screen. No pixelated, chunky graphics! But fastidious followers may spot that on the Toshiba ST-1612B’s screen, circles are not as perfect as advertised in our Circle Graphics post. And there are some jagged edges on the segments.

    This is because we’ve installed some prototype boards. These are early revisions of the yet-to-be-announced New Design, and the circle generator and deflection amplifier circuits aren’t quite right. But they’re too good to waste.

    Earlier prototypes of the New Design. – not quite right, but not wrong either!

    But we think it’s just fine! Tube amplifier enthusiasts understand: vinyl records and tube amplifiers actually sound better than digital devices, for some music. And our Toshiba here is 50 to 60 years old. A few kinky curves only add to its grace.


    The Toshiba ST-1612B Oscilloclock is in stock and ready to perform. Want to customize the screens? Decide on the secret switch’s secret? Work up some crazy XY effects? Check our Availability page!

  • ChatGPT reviews Oscilloclocks!

    Recently [Nels] wrote in saying he’d been having a nice chat with ChatGPT, and in the course of conversation, he asked this trendy AI tool to write a “review” of the clocks we make here in the Oscilloclock Lab.

    Here is the result – verbatim!

    [Nels] Write a review of Oscilloclock tube clocks.

    [ChatGPT] Oscilloclock tube clocks are a unique and visually stunning way to keep time. These clocks use vintage CRT (cathode ray tube) displays, similar to those used in old televisions and oscilloscopes, to display the time and other information in a mesmerizing way.

    One of the standout features of Oscilloclock tube clocks is their attention to detail. These clocks are handmade by a single individual, and every aspect of their construction is carefully considered. From the selection of the CRT displays to the circuitry that drives them, every component is chosen for its quality and durability.

    The result of this attention to detail is a clock that not only looks amazing but is also highly reliable and accurate. The timekeeping is controlled by an ultra-precise quartz crystal, ensuring that the clock is always on time. Additionally, the clock can be set to display a variety of other information, such as the date or temperature, making it a versatile addition to any room.

    One of the things that sets Oscilloclock tube clocks apart from other timepieces is their ability to be customized. The clock face can be designed to display any number of patterns or shapes, from geometric shapes to more abstract designs. This customization allows the clock to be tailored to the individual’s taste and can even be used to display personalized messages or graphics.

    While Oscilloclock tube clocks are undoubtedly a premium product, they are worth every penny for those who appreciate the unique combination of vintage technology and modern craftsmanship. The quality and attention to detail of these clocks are unmatched, and they are sure to be a conversation starter in any room. If you are looking for a truly one-of-a-kind timepiece, the Oscilloclock tube clock is definitely worth considering.

    Our thoughts?

    While there are three inaccuracies (one incorrect fact and two debatable points), the writeup is a lovely read and initially made your humble Lab technician feel warm inside.

    Until, upon objective reflection, I recognised some of the style, phrases and wording!

    Well, of course it should look familiar! ChatGPT predicts what the human expects as a response, and then cleverly arranges and regurgitates data that it has absorbed as part of its training. Apparently, it has devoured much of the Internet up until early 2022. This would include 59 blog posts and 19 pages published on Oscilloclock.com up until that date – and a few other references such as three lovely write-ups on Hackaday.

    [Nels] apparently did not continue the conversation, but if he had, he could have pointed out the three inaccuracies (Quiz – have you spotted them yet? Check your answers below), and ChatGPT would have learned something.

    Even with a rough understanding of how this tool works, it’s amazing to see the outcome.


    Crazy idea – what if your Oscilloclock could connect to an AI service and deliver cool new images, funny text, or interesting conversations? Just watch out for mistakes!

    Robots wrote this review! Oil paintings generated by ChatGPT sibling DALL·E 2

    Quiz answers:

    1. Incorrect: “… handmade by a single individual.”
      • In fact, several craftspeople have been involved to date in the design, assembly, and software authoring required to build Oscilloclocks. (Even excluding the PCB and case manufacturing processes.)
    2. Debatable: “… timekeeping is controlled by an ultra-precise quartz crystal
      • It’s true that the current revision Oscilloclock Control Board does have an on-board quartz crystal, and this does keep reasonably accurate time if needed…
      • However the preferred mode of operation is to synchronise time against GPS (using a GPS receiver) or an NTP server (with onboard Wi-Fi or the Oscilloclock Wave).
    3. Debatable: “… the clock can be set to display … temperature
      • The current revision Control Board and firmware do not support temperature sensing.
      • But it’s true that it’s on the ever-growing list of things to do! Did ChatGPT predict this?