In a desperate attempt to save his blog from becoming the all too familiar not-updated-in-5-years dead blog, the senior technician has resorted to seeking help from one of his sons, previously referred to as the 1st junior technician. Although my knowledge on CRTs and electronics is close to none compared to that of the senior technician, I will give you some updates on the recent activities of the main man himself, who I am sure all of you are eagerly awaiting the return of.
Amid the COVID-19 crisis, the senior technician has been lucky enough to be able to work at home. You would think that without his everyday commute of two hours, he would be more relaxed and able to spend more time with his family members. However, he is instead spending excessive time in front of the computer. At first, I speculated that he was having a rough time with his work. Or was he? Under closer examination, I realized that the additional time spent on the PC was actually something related to Oscilloclock. Something about a brand new design: “once-in-a-decade refresh,” and some such. Not really sure how significant this is to you all, but judging from the look on his face when he emerges from his room for dinner, it must be something BIG!
Another clue that the Oscilloclock Lab is heavily active is the vast array of international deliveries to our home in the past half year. Shipments from countries that you’ve never heard of, in all shapes and sizes, arriving so frequently that I can’t help feeling for the poor postman who has to carry these heavy objects up to our door. I must tell you, there is nothing worse than hearing the bell ring and rushing down to the door anticipating your own Amazon delivery of a new pair of shoes, and instead seeing a massive box from Montenegro containing who-knows-what-type-of-CRT.
The master craftsman’s work could very well be hindered by the noise from his two highly energised teenagers, [Oscillokid] and [Oscilloboy]. So how does he maintain concentration? The secret is a well-positioned cave. His workshop is intentionally situated at the very edge of the house. He simply closes the lone door to the shop, to avoid hearing a dinner-call or a request for more screen time from his Oscillosons. Until, of course, the commander-in-chief of the household raises her voice!
So there it is, a brief update on what’s going on and how the senior technician’s doing. Rest assured that he is working very hard on his projects, and has not in the least swayed from his passion; indeed, he is more immersed than ever. He will no doubt inform all of you anxious readers of his magnificent projects once they are ready for exposure. Until then, thanks for reading, and stay safe!
[Atif] is quite fond of his custom Oscilloclock Model 1, originally supplied with a bright green Brimar SE5F/P31 CRT. He just loves its crisp, clear trace! But wouldn’t it be great if he could plug-and-play a different CRT, to suit his mood of the day?
More specifically, could I create a second display unit (the acrylic tube on the left) using a CRT with a soft, long-persistence blue trace? And could he just swap the units around at will, without having to make any changes to the control unit?
Absolutely! But to make the 2nd unit completely compatible for plug-and-play, we’d need the same SE5F type CRT, with a different phosphor. Looking at Brimar’s catalogue, this CRT was available in several phosphors – including a P7 blue. This is the same as used in the original Prototype, and it’s really good at showing off those exotic trailing effects!
So the hunt began…
Now, this particular P7 CRT is famously difficult to come by – whether new OR used.
The most common piece of old equipment employing the SE5F was the ubiquitous Telequipment S51 oscilloscope, but the overwhelming majority of those had a P31 phosphor CRT installed. Indeed, of all the demonstrably working S51’s posted on eBay in the past decade, I have never seen a single one showing an obviously blue trace!
After many months of scouring auctions, suppliers and CRT fanatic colleagues across the globe, I managed to locate one SE5F/P7 in highly questionable condition – and located in Italy! With Google Translate as my friend, negotiations ensued, and – taking a substantial risk that the CRT would actually function – the unit was duly purchased and shipped.
Often, well-used CRTs exhibit scratches, spots, or burn-in marks on the internal phosphor coating. Fortunately, this CRT’s phosphor proved unblemished! And powering it up (for the first time in decades, most likely), it proved to be electrically faultless, as well!
Beautifying the Brimar
You may think that cleaning a CRT is hardly worth writing home (or the world) about.
But this specimen was slathered in sticky, gooey tape residue, which had to be carefully removed. My chemical of choice for this is, believe it or not, eucalyptus oil! Not only does it remove the gunk, but it also serves to clear up any nasal or bronchial congestion that the technician may have at the time. Two birds with one stone!
The more difficult issue was removal of the graphite coating. During manufacture, the front-most 8 cm of the glass of each SE5F was sprayed with a conductive graphite-based paint. Why? To make a high-voltage capacitor with the spiral accelerator anode (the beautiful green stripes) and similar graphite coating on the inside of the glass. By connecting the external coating to ground, the thrifty circuit designer could avoid using a separate (and expensive) high-voltage filter capacitor in the anode power supply!
Why remove this coating? Because during use, it gets scratched and marred, as the above photo shows. Such a messy CRT could never be worthy to mount in a clear cast-acrylic case for an Oscilloclock! In addition, the coating obscures some of the attractive spiral accelerator anode, and blocks the incredible view of the trace from behind. And regarding circuit design, we at Oscilloclock NEVER scrimp – the Power Board has oodles of filtering capacity without relying on a graphite coating!
While eucalyptus oil is also effective, it can get rather expensive in the quantity required – especially as the Oscilloclock lab is not conveniently located in Australia! The more reasonably priced chemical of choice here is nail polish remover. As always, there is a side-benefit – the nasal passages are assuaged by a delicate floral scent during cleaning, and fingers have an arguably nice smell that lingers for quite a while!
Joking aside – gloves, open windows, good ventilation, and safety glasses (in case the CRT implodes) are key ingredients for this process!
Having found the perfect CRT, [Atif]’s plug & play unit is now well under construction.
Epilogue – “Good things come in threes”
It’s not good just getting one CRT. What if [Atif] wanted a spare? What if I wanted a spare for my venerable Prototype clock? Following from the Italian success, I continued a further 6-month hunt, and managed two achievements.
The first was a Telequipment S51b unit located in the U.K. that was non-functional, but that I suspected may have a P7 phosphor installed. How could I possibly suspect this? Well, perhaps this is an art rather than a science, but there were several tell-tale signs:
The way the phosphor looked under the camera flash or ambient light
The colour (or absence) of the graticule (the plastic cover in front of the CRT)
The fact that I got a double when I rolled the dice to decide whether to take the plunge or not!
The seller of this unit was not willing (or perhaps not technically able) to extract the CRT, check the CRT type, or ship overseas. Fortunately, my colleague in the U.K. was more than happy to receive the scope at his end. Thus arranged, when the unit arrived he extracted the CRT and confirmed that – sadly – I had purchased a P31 CRT.
But I shipped it across anyway, and the CRT tested well. Rescuing a functional SE5F/P31 from eventual demise was still a worthy accomplishment!
The second achievement was prompted by an auction listing for a “Brimar SE5F”, but with little indication as to the phosphor. The photos of the label (see right), even with subsequent close-ups provided by the seller upon request, were not conclusive.
The image shows two characters beginning with ‘P’. It looks like “P1”, which is another extremely common green phosphor used in many CRTs since the beginning of time. However, we saw in the catalogue earlier that Brimar only supplied GV, P7, P31, and P39 phosphors as standard. It is unlikely that any equipment manufacturer would have requested Brimar to produce a custom CRT batch using the less-exotic P1 phosphor… Leaving the P7 as the only likely candidate!
Convinced, the CRT was duly shipped across and tested – and lo and behold, success! A spare P7 was safely procured.
And with that, the long saga of this CRT hunt closes. As they say, “good things come in threes!”
Like what you see?
Cathode ray tubes used to be manufactured in all shapes, sizes, and colours. Some prove harder than others to find! But if you prefer an exotic creation, don’t give up – there is something for you out there, and here at Oscilloclock we will find it.
As always, see previous posts and the Gallery for info on unique creations!
Recently I had an enquiry from [Frank], who had just begun a life-long love affair with scope clocks by purchasing one on eBay. The clock was great – but he felt that the two available screens (simple analogue and digital clock faces) lacked a certain oomph.
He then stumbled across Oscilloclock.com, and in his smitten state immediately reached out with his number one question: just what screens are available on an Oscilloclock?
Well, let me save Frank’s time trawling through years of blog posts. Right here in one place are most of the Oscilloclock screens and features created to date.
Enjoy the show!
Standard Time Screens
These stock-standard analogue and digital time screens may be quite simple, but they do evoke the ‘retro’ look that most people appreciate.
And you can flip a menu setting to display days, months, years in Japanese:
There are also some ‘random’ screens that add in a bit of dynamic visual entertainment:
Random number screen
Random letter sequence screen
Random four letter word screen (clean words only, by default!)
Random phrase screen (the phrase list is typically customized to a theme)
Over the years many folks have requested that I render custom logos in Circle Graphics. Here are some examples:
Up next are some fun, mildly interactive animation features. Not exactly screens per se, these animations pop up after a predefined period of inactivity – but only during certain months of the year. Can you guess which months?
There are far too many configuration menu and test screens to present here. Fiddle to your heart’s content!
Q. How are screens switched?
Screens are switched simply by rotating the control knob in one direction or other.
There is also a configurable auto-switch feature; the screen is changed every 90 seconds in a predefined order (with the exception of some animation screens). The display time is configurable, and the auto-switch feature can also be turned off for those who prefer to switch screens manually.
Q. How are screens selected & configured?
Customers can request screens to include and/or specify the switching order. The configuration is done here in the lab before clocks are delivered.
Oscilloclock also provides a firmware upgrade kit, which allows the customer to upload a revised version of the firmware into the clock themselves. Using this, updates to screens and other features can be uploaded without shipping the clock back to the lab.
Q. What is the process for rendering a custom screen or logo?
We typically prepare a mock-up based on the customer’s description, sketch, or image file. This is tweaked as needed until the screen looks just right to the customer.
These days, just about everyone has an old oscilloscope lying around. You know, an old, dusty, derelict scope handed down from Grandpa (or Grandma). Well, [Paul] had something even better – an old Tektronix 602 X-Y Monitor! Could an Oscilloclock Control Board drive this vintage beauty? Absolutely. Could I make an aesthetically pleasing case? Definitely. How about time sync via WiFi? Stock standard!
Presenting the Oscilloclock Connect:
Here’s what it looks like plugged in to my fabulous old Tektronix 620 monitor:
And why not have a pair of Connects drive a Tek 601 and 602?
The main component of the Connect is, of course, a standard Oscilloclock Control Board. As usual, all 121 parts on Paul’s board were individually mounted and soldered by hand. The board then was programmed and underwent rigorous inspection and testing. Finally, the board was cleaned to remove flux and renegade flecks of solder, and sprayed with HV coating for humidity protection and – arguably more importantly – to give it its glorious sheen.
The case was custom-made and professionally machined right here in Japan from 6mm-thick sheets of pure cast acrylic (not extruded). This is an extremely transparent, hard, high grade acrylic – and Oscilloclocks deserve nothing less!
The case was sprayed with a special acrylic cleaner and static protection solution, before fitting the various components. Naturally, every part was cherry-picked, right down to the three BNC connectors – they needed an aesthetically pleasing colour, but they also had to have a shaft long enough to mount through 6mm-thick acrylic!
Finally, the physical interface! The knob was chosen for its perfect finger-fit and delicate aluminium/black tones, which gently contrast with the rest of the unit.
The Compatibility Crisis
Over the years, many folks have observed that the scope at hand has an “X-Y mode”, and asked if they could just ‘plug in’ an Oscilloclock Control Board. “Is it compatible?” Unfortunately, the response has usually been disappointing.
You see, creating figures and characters with Circle Graphics relies on the scope’s ability to turn the beam on and off at split-second intervals. This feature is called a “Z-axis input”. While many scopes from the 80’s and beyond do sport such an input, there are two common limitations:
Limitation 1: AC-coupled Z-axis inputs
The input is connected to the CRT’s grid or cathode circuit via a capacitor. This is a low-cost, effective way to isolate the (usually) very high negative voltage of the grid circuit from the input.
The problem here is that the capacitor, by its very nature, removes the edges from the pulse. The controller is no longer able to control the beam on/off timing, and you end up with uneven blanking across the segments, as shown in the screenshot at right.
Depending on the values of the capacitor and the surrounding resistors, the symptoms may not be severe. However, the best way to resolve this problem (while still keeping the oscilloscope’s original circuit intact) is to insert an isolated DC blanking amplifier directly in series with the grid (or cathode). See the Kikusui 537 Oscilloclock for an example of this.
LIMITATION 2: INSUFFICIENT BLANKING AMPLIFICATION
Most oscilloscopes tend to require at least +5V on the Z-axis input to noticeably blank the beam. The Connect, however, is only capable of delivering +2.5V. It works just fine if you set the scope’s Intensity control very low, but as you increase intensity, the blanking quickly becomes ineffective.
Below we have a beautiful Japanese YEW (Yokogawa Electric Works) 3667 storage scope. The left shot is misleading due to the camera exposure; the displayed image is actually extremely dim. The right shot shows the same* image with the intensity control increased – the image is bright, but there is no blanking!
* Astute readers will observe that the time is significantly different between the two shots. This is a result of the WiFi NTP sync kicking in right in the middle! More (or less) astute readers may also notice that the scope’s trace rotation is not adjusted very well…
Of course, it would be a simple matter to incorporate a pre-amplifier for the Z-axis, which would solve this problem. This will be introduced with the next Control Board revision!
Like what you see?
Nothing brings more joy than connecting this bundle of usefulness into a woefully unused old oscilloscope or X-Y monitor. If this is of interest to you, visit the Availability page for more information, and of course see the Gallery for other unique creations!
Diverging from CRTs only briefly but holding steadfast to the warm, soft glow of valves, here I introduce a piece of Valve Art crafted long before Oscilloclock came into existence!
I spotted this vintage 1967 ultrasonic cleaner unit at the local Ham Fair, and it was love at first sight. Originally with a steel cabinet with peeling paint, the unit wasn’t much to look at on the outside. But after applying a copper coat to the chassis and fitting a sleek acrylic cabinet, this device simply dazzles!
Featuring not one, but two of these stunning Hitachi 3T12 transmitting valves!
Who needs a heater in winter, when you can have one of these power-hungry devices?
I bet this lovely triode, with its zirconium-plated anode and thorium-tungsten filament, really impressed the original owner of this ultrasonic cleaner…
Sadly, my workshop no longer had room for this historic showpiece, so with a heavy heart, I recently powered it down for the last time. However it will go to a loving new home…
As I’ve hinted before, your friendly Oscilloclock gang is entirely pacifistic. We abhor the thought of actual military activity in this modern day and age. BUT we love games just as much as anyone – and we also love light-hearted movies with happy endings!
So when [Ian] (of Bunker Club Clock fame) came up with the idea of a feature based on the iconic 1984 flick “War Games“, I pounced on the chance!
Now, this may look like a simple animation. But Ian’s Oscilloclock is powered by a tiny processor with minimal specifications, and 100% of the code is written in assembly language. Implementing this baby in assembly and keeping within just 3K of RAM was quite an accomplishment!!
About the host clock
The gorgeous model shown here is a painstakingly-retrofitted Heathkit CO-1015 Engine Analyzer. It’s the perfect play-toy for any serious motor-head who grew up during the Cold War!
First up on the custom build list is the original meter fitted with amber LED lighting and ticking audibly each second. (And yes, the tick intensity can be easily adjusted.)
Next up, there is the optional External X-Y input feature. Normally, this is used for plain and simple Lissajous figures like the below…
Peeking inside the Engine Analyzer Oscilloclock is also a must-do! Not only is this visually appealing, but you also get a significant olfactory kick from the sweet smell of vintage electronic components…
Attractive Oscilloclock boards and cabling, neatly tucked away
The original circuit is completely bypassed – but still looks awesome!
Tech Talk – Strategies, Maps, and Missiles
The War Games feature uses the Oscilloclock’s Sprite Engine module to display the world map and up to 9 missiles when the W.O.P.R. system is simulating various war strategies.
32 of the 130+ strategies seen in the movie are implemented. For each strategy, a random number of missiles are launched along a predefined Primary trajectory, followed by a random number of missiles along a predefined Retaliatory trajectory. If any of the 9 missiles remain, they are launched along randomly selected (but predefined) trajectories.
Trajectories are predefined because computing them using 8-bit arithmetic would consume a huge number of cycles! At least, a small amount of randomness is added to the launch position and velocity parameters at run-time, to make things more interesting.
As the simulation progresses through the strategies, the speed of the launches increases and the delay between launches decreases. This gives a similar effect to that in the move, where WOPR moves through strategies at warp speed until it realises that there is no winning this game…
A Joint Effort
Creating a huge number of realistic trajectories (68 in total), translating start and end X and Y coordinates from latitude and longitude into the Oscilloclock’s Cartesian plane was a task of mind-blowing proportions! Here we see our 2nd junior technician eagerly earning his room and board.
Like what you see?
Are you a petrol-head? You need an Engine Analyzer ticking over at your bedside or in your office! Were you brought up during the Cold War, perhaps in the Soviet Union or in the US? Get the War Games feature and fry the world safely! Contact me if you like what you see.
(Disclaimer: Oscilloclock.com hopes that no-one is offended by the deliberately light-hearted tone of this post, in referring to the decidedly serious topic of nuclear warfare.)
When I first heard from [Masahalu], a local artist and woodwork craftsman, I had a hunch that Oscilloclock history was about to be made.
His request initially seemed simple; he wanted an Oscilloclock Core – a bare-bones board and CRT assembly, which he could install into a case of his own design.
However, he wanted something totally unique. Something old, yes, but also something new. The artist in him demanded a different canvas of creativity.
Presenting Masahalu’s new canvas: A 5″ amber CRT Oscilloclock!
The new-old-stock CRT shipped with this unit features a P12 phosphor, and was originally produced for use in radar equipment. The phosphor’s long after-trace (persistence) allows for some fascinating ‘trailing effects’ in the Oscilloclock’s various animations.
Those familiar with CRT phosphors may point out that P12 is often classified as an orange phosphor, not “amber”. To my eye, though, the soft, warm trace of this CRT is better associated with eons-old fossilized tree resin than the sharp, bright color of fruit.
Amber CRTs are quite rare, especially in larger sizes. 3-inch P12 CRTs can be found, but the Oscilloclock Lab was fortunate to find several of these rare 5-inch CRTs.
[Masahalu] has certainly ended up with the unique canvas he requested, and we look forward to seeing what kind of case design he ends up with!
Like what you see?
It’s so much fun letting these cathode ray tubes shine their colourful rays again! Whether you’re into yellow, amber, blue, white, or just plain green, there is something here for you. Visit the Availability page for more information, and of course see the Gallery for other unique creations!
Fake news – a common keyword these days. Fortunately, Oscilloclocks do not display fake news. But wouldn’t it be handy to see quake news on an exotic scope clock? This is the challenge [Atif] gave me – and one year and many grey hairs later, here is the result: The AfterShock Clock!
This custom-crafted Oscilloclock Core Duo assembly is a unique first in several ways:
It’s the first scope clock ever that pulls in and displays real earthquake data!
It’s the first scope clock ever that puts a dual-beam CRT to good use – one beam for the clock display, and the other for the earthquake and map overlay!
The AfterShock Clock’s WiFi module connects at regular intervals to two public APIs (servers) to collect the latest earthquake events. It then feeds earthquakes to the clock’s quake gun controller, rotating quakes every 30 seconds. Cool!
(Note: flickering is due to camera effects and is not visible to the human eye)
Of course, there is the usual wide variety of standard clock screens to cycle through! The quake map’s beam is automatically dimmed for most of the screens, giving a soft ‘watermark’ effect.
The E10-12GH CRT used in this clock is certainly not mundane!
Beautiful spiral PDA lets you really see inside the cavity!
Nothing beats a dual-gun CRT for intricacy… (except a quad- or pentuple-gun CRT!)
Oscilloclock Core Duo
Atif wanted to create his own case, so he initially asked for an Oscilloclock Core. But currently a single Core set does not provide control, deflection, and blanking circuits to drive TWO electron guns… So he had two choices:
Wait an eternity for me to redesign the boards to fully support dual beams.
Get started now! Simply put two Core assemblies together, with some degree of inter-control and removing any redundant circuits.
Atif chose the latter – and the Oscilloclock Core Duo was born!
Setting up the WiFi connection is easy – just connect a device to the clock’s administration SSID and pull up the admin page. (To foil any would-be hackers out there, the admin SSID is available only for the first 5 minutes after power is applied.)
Then, access the admin URL and configure the connection to your home router:
There are a million other advanced settings to tweak things such as quake polling interval, quake magnitude filters, maximum quake age before purge, and other geeky aspects….
Oh, I forgot to mention – the clock also synchronizes time against an NTP server, eliminating the need for a GPS module.
Like what you see?
Do you go for electron guns? idolize intricate electrode assemblies? Have a filament fetish? Or just want some quake news? This kind of clock might fit the bill. Let me know!
Some readers may be curious just where these crazy Oscilloclock devices are actually made. While the question of WHO makes them shall remain a mystery, let’s definitely take a close look through the mad scientist’s laboratory!
This panoramic view of the depths of the shop makes the place look huge, but in fact it is a tiny 8.2 square metres (88 square feet)!
The entire workshop “sits” on the floor and is self-supporting – almost nothing is screwed in to the walls.
Perhaps the kind reader might think this is the production of a master woodworker. In fact, nothing could be further from the truth! This was the very first piece of furniture I have ever built – and as you can see, it was quite a project…
First and foremost, I used SketchUp to create an accurate scale model of the workshop. I modelled every piece of equipment I wished to eventually mount, and tested hundreds of layouts until coming to a final design. What an effort!
Here I’ve loaded it into an STL viewer so you can play with it:
Most of the workshop is made from pine. All pieces of wood were cut from slabs using a cheap and nasty hand-held circular saw, as I did not have easy access to a table saw at the time. This was painstaking!
The workbench surfaces are solid maple for hardness and longevity. Linseed oil was used as a finish, to keep things natural. Unfortunately, I have been rather lazy and have neglected to apply further coats since making the workshop!
Maple, Pine, and lots of linseed oil!
Drawers under the benches were crafted carefully to allow resident Oscilloclock artists to sit with plenty of leg room, and drawer slides were chosen with appropriate length such that the drawers open out far enough to access fully.
Cabinets were fitted with adjustable internal shelving, and lovely hinges that allow access to the full width of the shelf even when the door is only open 90 degrees.
Shelves were fitted above windows on one side of the room, mostly to store my extensive collection of 1940’s to 80’s Australian electronics magazines (Radio and Hobbies, Radio Television & Hobbies, and Electronics Australia). These shelves are the only pieces in the workshop that are actually screwed into the walls.
For the reference bookshelf, I cheated and used a standard flexible solution from the local hardware store. It looks reasonable enough…
The shop has its own electric meter, a second-hand one rescued from the junk pile. This one is designed for a much higher current than the humble Oscilloclock lab usually consumes, but it spins fast enough if I turn on enough equipment!
The shop is equipped with no fewer than five different power supply lines, all at the resident frequency of 50Hz:
100V – This may give away the lab’s country of residence…
100V isolated– For testing “hot chassis” devices
117V – Supplied by a massive, nasty 1500VA Variac
200V – Straight from the local power company
240V – Supplied by a massive hand-wound toroidal transformer
Earthed 100V, 117V, and 240V outlets are literally peppered around the workshop, mostly tucked away behind the shelves. Datacentre grade outlet boxes were employed for ultimate safety. The best part? All equipment is plugged in and ready to use at any instant in time!
Of course I also have a variable voltage, variable frequency AC power supply, which I use regularly when spinning up voltage into vintage gear, or when I need to evaluate power circuit performance at anywhere between 40 and 400Hz.
No shop should be without its own set of circuit breakers! Here we see two of the several dedicated switches. These employ earth leakage detection, of course.
A quick flick through the Oscilloclock blog reveals beyond any doubt that I have an extreme passion for vintage electronics. Nowhere is this more visually expressed than in this homey workshop. Every piece of equipment functions, and every piece is actually used at least once a year!
But I shall leave the equipment show-and-tell for another post!
Well, for the fun of course! But in fact, this workshop was built exclusively for the design and construction of exquisite hand-crafted scope clocks. So don’t delay in checking out the fruits of the lab – visit the Gallery right now!