Vector Network Analyzer Demo And Teardown

October 18, 2023 by Donald Papp 10 Comments

[Kerry Wong], ever interested in trying out and tearing down electrical devices, demonstrates and examines the SV 6301a Handheld Vector Network Analyzer. He puts the machine through its paces, noting that the 7 inch touchscreen is a pretty nice feature for those whose eyesight isn’t quite what it used to be.

The internals are similar to the nanoVNA-F V3, but not identical.

What’s a Vector Network Analyzer (VNA)? It’s not for testing Ethernet or WiFi. It’s aimed at a more classical type of “network”. The VNA tests and evaluates characteristics of electrical networks, especially as related to RF and microwave.

It provides detailed information about properties across a specified frequency range, making it an indispensable tool for advanced work. Tektronix has a resource page that goes into detail about exactly what kinds of things a VNA is good for.

[Kerry] shows off a few different features and sample tests before pulling the unit apart. In the end, he’s satisfied with the features and performance of the device, especially the large screen and sensible user interface.

After all, not every piece of test equipment does a great job at fulfilling its primary function, like the cheap oscilloscope that was a perhaps a little too cheap.

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Turning Soviet Electronics Into A Nixie Tube Clock

August 27, 2023 by Donald Papp 17 Comments

Sometimes you find something that looks really cool but doesn’t work, but that’s an opportunity to give it a new life. That was the case when [Davis DeWitt] got his hands on a weird Soviet-era box with four original Nixie tubes inside. He tears the unit down, shows off the engineering that went into it and explains what it took to give the unit a new life as a clock.

Each digit is housed inside a pluggable unit. If a digit failed, a technician could simply swap it out.

A lot can happen over decades of neglect. That was clear when [Davis] discovered every single bolt had seized in place and had to be carefully drilled out. But Nixie tubes don’t really go bad, so he was hopeful that the process would pay off.

The unit is a modular display of some kind, clearly meant to plug into a larger assembly. Inside the unit, each digit is housed in its own modular plug with a single Nixie tube at the front, a small neon bulb for a decimal point, and a bunch of internal electronics. Bringing up the rear is a card edge connector.

Continues after the break…

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Tivoli Teardown Disappoints

July 25, 2023 by Chris Lott 32 Comments

[Fran] has been curious about the innards of Tivoli Audio’s Model One radio, but was reluctant to shell out $200 just to tear it apart. But she found one recently on eBay, won the auction, and proceeded to do a review and teardown. Spoiler alert, she was disappointed.

Physically speaking, the radio looks great and has quite an array of I/O connections. The geared tuning knob looks cool, but is heavily damped which [Fran] isn’t keen about. Turning it on, a few more quirks are discovered. The volume control is out-of-whack — it appears they substituted a linear taper potentiometer where a logarithmic taper was called for.

Another problem, at least in the RF-dense metropolitan areas like Philadelphia, is the FM tuner’s station-lock feature. It is so strong that it can be impossible to tune in weak stations. This is especially ironic since, according to Wikipedia, that was one of audio engineer Henry Kloss’s main goals when founding Tivoli Audio back in 2000:

Their first product was the Model One, a simple to use mid-century modern designed table top radio with a high-performance tuner, receiving FM radio in congested urban locations, while maintaining the ability to pick out distant or low power stations. Kloss had noted that the mid 60’s wave of Japanese radios lacked the ability to receive FM stations in congested locations, and this became a defining goal of his radio designs throughout his career.

Interestingly, many folks in the YouTube comments say their Model One radios have none of these issues. We wonder if [Fran] has obtained a damaged radio, or maybe a newer version produced with less attention to detail. If you have a broken Model One radio, before tossing it, consider the hack we wrote about last year, turning it into an internet radio.

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Tearing Down And Improving A Professional Power Supply

July 11, 2023 by Al Williams 11 Comments

[OZ2CPU] has an HP power supply that is about 30 years old. It looks brand new, though, and has three outputs and includes tracking for the adjustable positive and negative supply. After a quick demo of the unit’s features, he tears it all down so we can see inside. You can catch the video below.

Some similar supplies offer a 10-turn adjustment knob, but this one doesn’t. Inside is a beefy transformer and quite a few through-hole components. There was room to change the main adjusted pot to a 10-turn unit, so he made the mod.

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Teardown Of An Aircraft Video Symbol Generator

June 19, 2023 by Dave Rowntree 17 Comments

[Adrian Smith] recently scored an avionics module taken from a British Aerospace 146 airliner and ripped it open for our viewing pleasure. This particular aircraft was designed in the early 1980s when the electronics used to feed the various displays in the cockpit were very different from modern designs. This particular box is called a ‘symbol generator’ and is used to generate the various real-time video feeds that are sent to the cockpit display units. Various instruments, for example, the weather radar, feed into it, and it then reformats the video if needed, mixing in any required additional display.

Top view of the symbol generator instrument rack

There are many gold-plated chips on these boards, which indicates these may be radiation-hardened versions of familiar devices, most of which are 54xx series logic. 54xx series logic is essentially the same functionally as the corresponding 74xx series, except for the much wider operating temperature range mandated by military and, by extension, commercial aviation needs. The main CPU board appears to be based around the Intel 8086, with some Zilog Z180 compatible processors used on the two video display controller boards. We noted the Zilog Z0853604, which is their counter/timer/GPIO chip. Obviously, there are many custom ASICs produced by Honeywell as well as other special order items that you’ll never find the datasheet for. Now there’s a challenge!

Finally, we note the standard 400 Hz avionics-standard power supply, which, as some may know, is the standard operating frequency for the AC power system used within modern aircraft systems. The higher frequency (compared to 50 or 60 Hz) means the magnetic components can be physically smaller and, therefore, lighter for a given power handling capability.

We see a lot of avionics teardowns, likely because they’re fascinating. Here’s some more British military gear, an interesting RF distance measuring box from the 1970s, and finally, some brave soul building their own avionics gear. What could possibly go wrong?

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Google Nest Hub Teardown

May 29, 2023 by Matthew Carlson 16 Comments

Seeing the guts of devices is a fascination that many hackers share. [Txyz] tore down a 2nd gen Google Nest Hub for all of us to enjoy. The video after the break is well produced and relaxing to watch as various heat shields are removed and debug cables are soldered on.

The main SOC is an Amlogic S905D3G, a 4-core A55-based SoC. The important chips are meticulously documented, and it’s a fascinating look inside a device common in many people’s homes. One chip that’s of note is the BGT60TR13C, otherwise known as Project Soli. It is an 8x10mm chip that uses radar to detect movement with sub-millimeter accuracy. This allows the device to measure your sleep quality or recognize gestures. Luckily for us, [Txyz] has included a datasheet and a block diagram. First, the chip fills a FIFO with data samples. Once full, it will issue an interrupt to the main SoC, which empties the buffer via SPI.

The debug cables allowed him to capture traces of the SPI commands to the BGT60TR13C. [Txyz] focused on decoding the various data blocks and the configuration registers. Unfortunately, only a few registers are documented in the datasheet, and it isn’t apparent what they do.

If a hardware teardown isn’t enough for you, perhaps a software teardown to bypass Secure Boot might sate your interest.

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A Mobile Phone From 1985

May 25, 2023 by Bryan Cockfield 6 Comments

It might seem quaint through the lends of history we have the luxury of looking through, but in the mid 1980s it was a major symbol of status to be able to communicate on-the-go. Car phones and pagers were cutting-edge devices of the time, and even though there were some mobile cellular telephones, they were behemoths compared to anything we would recognize as a cell phone today. It wasn’t until 1985 that a cell phone was able to fit in a pocket, and that first device wasn’t just revolutionary because of its size. It made a number of technological advancements that were extremely impressive for its time, and [Janus Cycle] takes us through some of those in this teardown video.

The Technophone came to us from Great Britain by way of a former Ericsson engineer named Nils Mårtensson. It was able to achieve its relatively small stature using a surface-mount PCB, which was a cutting-edge manufacturing process for the time. Not only did it use surface-mount components and boards, but the PCB itself has 12 layers and two sides and hosts two custom Technophone chips. The phone is relatively modular as well, with the screen, battery pack, and other components capable of easily disconnecting from the main board. Continue reading “A Mobile Phone From 1985” →