The Sony ScopeMan, Possibly The Best Product They Never Made

From the perspective of a later decade it’s sometimes quaint and amusing to look back at the technological objects of desire from times past. In the 1980s for example a handheld television was the pinnacle of achievement, in a decade during which the Walkman had edged out the transistor radio as the pocket gadget of choice it seemed that visual entertainment would surely follow. Multiple manufacturers joined the range of pocket TVs on offer, and Sony’s take on the format used a flattened CRT with an angled phosphor screen viewed from behind through its glass envelope. [Niklas Fauth] took one of these Sony Watchman devices and replaced its TV circuit board with one that turned it into a vector display. The Sony Scopeman was born!

The schematic is deceptively simple, with an ESP32 receiving audio via Bluetooth and driving the deflection coils through a pair of op-amps and a set of driver transistors. These circuits are tricky to get right though, and in this he acknowledged his inspiration. Meanwhile the software has two selectable functions: a fairly traditional X-Y vector ‘scope display and a Lorenz attractor algorithm. And of course, it can also display a vector version of our Wrencher logo.

We like the Scopeman, in fact we like it a lot. There may be some discomfort for the retro tech purist in that it relies on butchering a vintage Watchman for its operation, but we’d temper that with the observation that the demise of analogue broadcast TV has rendered a Watchman useless, and also with the prospect that a dead one could be used for a conversion project.

[Niklas] has had more than one project appear on these pages, a memorable example being his PCB Tesla coil.

Vintage Plotter Handles Chaos With Ease

No lab in almost any discipline was complete in the 70s and 80s without an X-Y plotter. The height of data acquisition chic, these simple devices were connected to almost anything that produced an analog output worth saving. Digital data acquisition pushed these devices to the curb, but they’re easily found, cheap, and it’s worth a look under the hood to see what made these things tick.

The HP-7044A that [Kerry Wong] scored off eBay is in remarkably good shape four decades after leaving the factory. While the accessory pack that came with it shows its age with dried up pens and disintegrating foam, the plotter betrays itself only by the yellowish cast to its original beige case. Inside, the plotter looks pristine. Completely analog with the only chips being some op-amps in TO-5 cans, everything is in great shape, even the high-voltage power supply used to electrostatically hold the paper to the plotter’s bed. Anyone hoping for at least a re-capping will be disappointed; H-P built things to last back in the day.

[Kerry] puts the plotter through its paces by programming an Arduino to generate a Lorenz attractor, a set of differential equations with chaotic solutions that’s perfect for an X-Y plotter. The video below shows the mesmerizing butterfly taking shape. Given the plotter’s similarity to an oscilloscope, we wonder if some SDR-based Lissajous patterns might be a fun test as well, or how it would handle musical mushrooms.

Continue reading “Vintage Plotter Handles Chaos With Ease”