Teardown

509 Articles

Not A Sewing Machine: A Multimedia Briefcase

May 15, 2025 by 10 Comments

When you think of Singer, you usually think of sewing machines, although if you are a history buff, you might remember they diversified into calculators, flight simulation, and a few other odd businesses for a while. [Techmoan] has an unusual device from Singer that is decidedly not a sewing machine. It is a 1970s-era multimedia briefcase called the Audio Study Mate. This odd beast, as you can see in the video below, was a cassette player that also included a 35mm filmstrip viewer. Multimedia 1970s-style!

The film strip viewer is a bright light and a glass screen with some optics. You have to focus the image, and then a button moves the film one frame. However, that’s for manual mode. However, the tape could encode a signal to automatically advance the frame. That didn’t work right away.

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Inside Starlink’s User Terminal

May 14, 2025 by 31 Comments

If you talk about Starlink, you are usually talking about the satellites that orbit the Earth carrying data to and from ground stations. Why not? Space is cool. But there’s another important part of the system: the terminals themselves. Thanks to [DarkNavy], you don’t have to tear one open yourself to see what’s inside.

The terminal consists of two parts: the router and the antenna. In this context, antenna is somewhat of a misnomer, since it is really the RF transceiver and antenna all together. The post looks only at the “antenna” part of the terminal.

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What’s An LCR Databridge?

May 13, 2025 by 6 Comments

[Thomas Scherrer] has an odd piece of vintage test equipment in his most recent video. An AIM LCR Databridge 401. What’s a databridge? We assume it was a play on words of an LCR bridge with a digital output. Maybe. You can see a teardown in the video below.

Inside the box is a vintage 1983 Z80 CPU with all the extra pieces. The device autoranges, at least it seems as much. However, the unit locks up when you use the Bias button, but it isn’t clear if that’s a fault or if it is just waiting for something to happen.

The teardown starts at about six minutes in. Inside is a very large PCB. The board is soldermasked and looks good, but the traces are clearly set by a not-so-steady hand. In addition to AIM, Racal Dana sold this device as a model 9341. The service manual for that unit is floating around, although we weren’t able to download it due to a server issue. A search could probably turn up copies.

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Tearing Down A Forgotten Video Game

May 11, 2025 by 5 Comments

Remember Video Volley? No? We don’t either. It looks like it was a very early video game console that could play tennis, hockey, or handball. In this video, [James] tears one apart. If you are like us, we are guessing there will be little more than one of those General Instrument video game chips inside.

These don’t look like they were mass-produced. The case looks like something off the shelf from those days. The whole thing looks more like a nice homebrew project or a pretty good prototype. Not like something you’d buy in a store.

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Inside A Selective Voltmeter

May 9, 2025 by No comments

[Martin Lorton] has a vintage Harmon 4200B selective voltmeter that needed repair. He picked it up on eBay, and he knew it wasn’t working, but it was in good condition, especially for the price. He’s posted four videos about what’s inside and how he’s fixing it. You can see the first installment below.

The 4200B is an RMS voltmeter and is selective because it has a tuned circuit to adjust to a particular frequency. The unit uses discrete components and has an analog meter along with an LCD counter.

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Oscilloscope Digital Storage, 1990s Style

May 9, 2025 by 13 Comments

You’re designing an oscilloscope with modest storage — only 15,000 samples per channel. However, the sample rate is at 5 Gs/s, and you have to store all four channels at that speed and depth. While there is a bit of a challenge implied, this is quite doable using today’s technology. But what about in the 1990s when the Tektronix TDS 684B appeared on the market? [Tom Verbure] wondered how it was able to do such a thing. He found out, and since he wrote it up, now you can find out, too.

Inside the scope, there are two PCBs. There’s a CPU board, of course. But there’s not enough memory there to account for the scope’s capability. That much high-speed memory would have been tough in those days, anyway. The memory is actually on the analog board along with the inputs and digitizers. That should be a clue.

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The Owon HDS160 Reviewed

May 8, 2025 by 11 Comments

These days, if you are in the market for a capable digital voltmeter, you might as well consider getting one with an oscilloscope built-in. One choice is the Owon HDS160, which [Kerry Wong] covers in the video below. The model is very similar to the HDS120, but the multimeter in the HDS160 has more counts–60,000 vs 20,000 as you might expect from the model number.

The internal chip is an HY3131, which is rated at 50,000 counts which is odd since the meter is 60,000 counts, but presumably the meter uses some capability of the chip, possibly putting it out of spec. The oscilloscope is the same between the two models. Almost everything else works the same, other than the capacitance measuring feature, as the video shows.

The difference in cost between the two units isn’t much, so if you are shopping, the small extra cost is probably worth it. Not that a 20,000 count meter isn’t perfectly fine for most normal uses.

[Kerry] really likes scopemeters. He gets excited about bench scopes, too.

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