A Tale Of Two (Sub $100) Oscilloscopes

Hi, I’m Al, and I’m an oscilloscope-holic. Just looking around my office, I can count six oscilloscope or oscilloscope-like devices. There are more in my garage. If you count the number of scopes I’ve owned (starting with an old RCA scope with a round tube and a single vertical scale), it would be embarrassing.

On the other hand, if you are trying to corral electrons into doing useful things, a scope is a necessity. You can’t visualize what’s happening in a circuit any better than using an oscilloscope. Historically, the devices were expensive and bulky. I’ve had many Tektronix and HP scopes that stayed in one place, and you brought what you were working on to them (sometimes called a “boat anchor”). It wasn’t that long ago that one of my vintage Tek scopes had its own dedicated cart so I could wheel it to where it was needed.

These days, scopes are relatively cheap, depending on what you have in mind for performance. They are also highly portable, which is nice. In fact, it is an indication of how spoiled I’ve become that my main bench scope–a Rigol DS1104Z–weighs seven pounds, yet I still look for something smaller for quick jobs.

That’s how I came into possession of two cheap scopes I wanted to talk about. They are similar in ways but different in others. Neither are going to replace a real bench scope, but if you want something portable, or you are budget-limited, they might be worth a look.

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I Built Myself A 16×20-Inch Camera In 10 Hours

[Giles Clement] was avoiding work in a bar, nursing a pint, and doodling a sketch for a camera. He looked at his sketch, thought, “gee, that looks better than answering emails,” and called his friend. An hour later they were at home depot buying supplies, and ten hours of furious work later, they had a camera. Nothing gets a project done like avoiding work! (See it all happen before your eyes in the video below the break.)

The camera is built around a 500mm f/4.5 Goerz Dogmar lens from around 1918 and was apparently used for aerial recon out of blimps. The frame of the camera is pine and plywood. [Giles] had heard that building the bellows for these cameras had taken other hobbyists months and thousands of dollars. Rather than elaborately folded fabric, he supported his 6 mil plastic bellows on telescoping rigid rods. To view the image while he’s focusing it, he sanded a plate of glass with 100 grit sandpaper to serve as a view screen.

Once the camera was completed, they prepared the plates and exposed photos. The first step, from what we could tell, was to disregard all chemical safety practices. The second step was pouring a substance called collodion on an unsanded glass plate and tilting the plate back and forth until the whole plate had an even coat on it. Then it was put in a bath of silver nitrate to sensitize. Once sensitized the plate was placed in the frame of the focused camera and an astonishing amount of strobe light emitted. After that it’s back to the chemical baths for more safety hazards. The whole process has to be done under fifteen minutes or the plate cures before it can be used. The photos that come out are seriously cool. It’s no wonder these old styles of photography have seen a comeback.

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Robot Solves Rubik’s Cube In Just One Second

Some of the fastest Rubik’s cube solvers in the world have gotten down to a five second solve — which is quite an incredible feat for a human — but how about one second? Well, [Jay Flatland] and [Paul Rose] just built a robot that can do exactly that.

The robot uses four USB webcams, six stepper motors, and a 3D printed frame. The only modification to the Rubik’s cube are some holes drilled in the center pieces to allow the stepper motors to grip onto them with 3D printed attachments.

The software is running off a Linux machine which feeds the data into a Rubik’s cube algorithm for solving. In approximately one second — the cube is solved.

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