Laser-Engraving Hairlines: When A Line Isn’t A Line

When is a line not a line? When it’s a series of tiny dots, of course!

The line is actually tiny, laser-etched craters, 0.25 mm center-to-center.

That’s the technique [Ed Nisley] used to create a super-fine, colored hairline in a piece of clear plastic — all part of his project to re-create a classic Tektronix analog calculator from the 1960s, but more on that in a moment.

[Ed] tried a variety of methods and techniques, including laser engraving a solid line, and milling a line with an extremely tiny v-tool. Results were serviceable, but what really did the trick was a series of tiny laser-etched craters filled in with a red marker. That resulted in what appears — to the naked eye — as an extremely fine hairline. But when magnified, as shown here, one can see it is really a series of small craters. The color comes from coloring in the line with a red marker, then wiping the excess off with some alcohol. The remaining pigment sitting in the craters gives just the right amount of color.

This is all part of [Ed]’s efforts to re-create the Tektronix Circuit Computer, a circular slide rule capable of calculating all kinds of useful electrical engineering-related things. And if you find yourself looking to design and build your own circular slide rule from scratch? We have you covered.

Cardboard Models Trace Design Process Of Vintage Tektronix Miniscopes

There aren’t many brands that inspire the kind of passion and fervency among its customers as Tektronix does. The venerable Oregon-based manufacturer of top-end test equipment has produced more collectible gear over the last 75 years than just about anyone else.

Over that time they have had plenty of innovations, and in the 1970s they started looking into miniaturizing their flagship oscilloscopes. The vintageTEK museum, run by current and former employees, has a review of the design process of the 200 series of portable oscilloscopes that’s really interesting. At a time when scopes were portable in the way a packed suitcase is portable, making a useful instrument in a pocketable form factor was quite a challenge — even for big pockets.

The article goes into great detail on the back-and-forth between the industrial designers, with their endless stream of models, and the engineers who would actually have to stuff a working scope into whatever case they came up with. The models from the museum’s collection are wonderful bits of history and show where the industrial designers really pushed for some innovative designs.

Some of the models are clearly derived from the design of the big bench scopes, but some have innovative flip-down covers and other interesting elements that never made it to production. Most of the models are cardboard, but some were made of aluminum in the machine shop and sport the familiar “Tek blue” livery. But the pièce de résistance of the collection is a working engineering model of what would become the 200-series of miniscopes, a handmade prototype with a tiny round CRT and crudely labeled controls.

The vintageTEK museum sounds like another bucket-list stop for computer and technology history buffs. Tek has been doing things their own way for a long time, and stopping by the museum is sure to be a treat.

Thanks to [Tanner Bass] for the tip.

Inside A $30,000 8 GHz Scope

One of the best things about the Internet — especially the video part — is that you can get exposed to lots of things you might otherwise not be able to see. Take oscilloscopes, for example. If you were lucky, you might have one or two really nice instruments at work and you certainly weren’t going to be allowed to tear them open if they were working well. [The Signal Path], as a case in point, tears down a $30,000 MSO6 8 GHz oscilloscope.

Actually, the base price is not quite $30,000 but by the time you outfit one, you’ll probably break the $30K barrier. Compared to the scopes we usually get to use, these are very different. Sure, the screens are larger and denser, but looking at the circuit boards they look more like some sort of high-end computer than an oscilloscope. Of course, in a way, that’s exactly what it is.

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Upgrading The RAM In A 25 Year Old Oscilloscope

From reading his extensive write-ups on the subject, there’s one thing we know for sure: [Tom Verbeure] loves his Tektronix TDS 420A oscilloscope. While it might be older than some of the people reading this, it’s still an impressive piece of hardware with more than enough bells and whistles to keep the average hacker occupied. Especially if you’re willing to perform some hardware modifications.

Note the battery to retain calibration data.

[Tom] already knew how to tickle the scope into unlocking software features, a process not unlike what we’ve seen done on more modern scopes. But there’s only so far you can get by toggling software flags.

Some of the more advanced features that are turned off in the firmware actually need additional hardware to function. Simply bumping the sample points to 120,000 in software wasn’t enough, the scope actually needs the memory to hold them in.

Now logically, if there’s a software option to increase the number of samples, there must be a hardware upgrade that goes along with it. Sure enough, [Tom] found there were 6 open spots next to the scope’s existing M5M51008 static RAM ICs.

As luck would have it the chips are still available, albeit from a different manufacturer and a bit faster than the original parts. Digikey wouldn’t sell fewer than 100 of them, but UTSource was happy to sell him 10. In this case, the parts were cheaper than the shipping cost. Installation was about as straightforward as it gets, though [Tom] does note that he had to keep the board powered up during the operation or else the scope would have lost its calibration data.

Squeezing more features out of modern scopes like the Rigol DS2072A just takes a USB cable and some software. Sometimes it’s only a matter of tapping in a code. But we certainly appreciate [Tom] putting in a little extra effort to get the most out of this classic piece of hardware.

Tubes Have Character With A Tek 570

When tubes were king, you could go to a drugstore with a box full of them from your TV. There would be a tester that would tell you what tubes were bad and, of course, you could buy the replacements for them. That kind of tube tester was pretty simple. If you wanted to really know how to design with a tube or test its parameters, you were much better off with a curve tracer like the Tektronix 570 that [tomtektest] shows off in two recent videos that you can see below.

That piece of kit fell into [Tom’s] lap thanks to an observant delivery driver. The 1955 instrument is very similar to a semiconductor curve tracer but, of course, has the ability to provide much higher voltage for the tubes. The basic idea is that the X axis sweeps from a few volts up to 100s of volts. The vertical scale will show the plate, screen, or grid current. From those curves you can learn a lot about the characteristics of the tube.

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Recreating Fast Oscilloscopes Is A Slow Process

If you want to do something you’ve never done before, there are two broadly-defined ways of approaching it: either you learn everything you can about it and try to do it right the first time, or you get in there and get your hands dirty, and work out the details along the way. There’s a lot to be said for living life by the seat of your pants. Just ask anyone who found inspiration in the 11th hour of a deadline, simply because they had no other choice.

Ted Yapo didn’t have a lot of high-speed design knowledge when he set out to build an open-source multi-GHz sampling oscilloscope, but he didn’t let that stop him. Fast forward a year or so, and Ted’s ready to build his third prototype armed with all the hands-on practical knowledge he’s gained from building the first two.

At the 2019 Hackaday Superconference, Ted gave a talk about his journey into the high-stakes world of high-speed design. It’s an inspiring talk, and Ted gives a good look into everything he’s learned in trying to build a sampling ‘scope. We think you’ll appreciate not only Ted’s work, but also the ease with which he explains it all.

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Incredibly Heavy Ornament Likely Inappropriate To Hang On Tree

It’s that time of year again, and the Christmas hacks are flooding in thick and fast. To get into the Christmas spirit,  the FoxGuard team wanted a custom ornament to hang from the tree. They may have gotten more than they bargained for.

It’s a simple build that demonstrates the basic techniques of working with DACs and scopes in a charming holiday fashion. A Tektronix T932A analog oscilloscope is pressed into service as a display, by operating in XY mode. A Teensy 3.5 was then chosen for its onboard digital to analog converters, and used to output signals to draw a Christmas tree and star on the screen.

Old-school coders will appreciate the effort taken to plot the graphics out on graph paper. While the hack doesn’t do anything cutting edge or wild, it’s impressive how quick and easy this is thanks to modern development methods. While the technology to do this has existed for decades, a hacker in 1998 would have spent hours breadboarding a PIC microcontroller with DACs, let alone the coding required. We’ve come a long way.

It’s a bit of fun, but we highly recommend you don’t try and hang an analog scope off your tree at home. These WiFi-controlled ornaments are perhaps more suitable. Video after the break. Continue reading “Incredibly Heavy Ornament Likely Inappropriate To Hang On Tree”