Hacking A Vintage TV Into An Oscilloscope

April 6, 2017 by Manuel Rodriguez-Achach 15 Comments

Do you still have an old analog CRT television lying around? With the advent of digital signals, analog TV´s are going to the dumpster or the recycling center. But you can still put them to good use, just as [GreatScott!] did, by converting the TV into a crude oscilloscope.

The trick is to take control of the two deflection coils that move the electron beam inside the CRT in the horizontal and vertical directions. The video describes in detail the process of identifying the coils and using an Arduino nano in combination with a DAC to amplify the input signal in order to get the waveform in the TV screen. Step by step explanations and great editing make this project delightful to watch.

Even if you do not follow [GreatScott!]´s steps to build a simple oscilloscope, don´t throw away that vintage TV!, it is a great source of analog parts. The flyback transformer can be used to make a high voltage power supply, and you also get some nice high voltage capacitors (both electrolytic and mylar ones), the horizontal output transistor which is a high voltage one, ferrite transformers, magnet wire, plus a lot of other small parts. Other uses for old TV sets that you may want to try is to convert your TV into a gaming console, or an audio synthesizer controlled by drawing with a light-sensitive pen on a CRT television.

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A Walk-In Broadcast Transmitter

April 5, 2017 by Dan Maloney 20 Comments

[Mr. Carlson] likes electronics gear. Mostly old gear. The grayer the case, the greener the phosphors, and the more hammertone, the better. That’s why we’re not surprised to see him with a mammoth AM radio station transmitter in his shop. That it’s a transmitter that you can walk into while it’s energized was a bit of a surprise, though.

As radio station transmitters go, [Mr. Carlson]’s Gates BC-250-GY broadcast transmitter is actually pretty small, especially for 1940s-vintage gear. It has a 250 watt output and was used as a nighttime transmitter; AM stations are typically required to operate at reduced power when the ionosphere is favorable for skip on the medium frequency bands. Stations often use separate day and night transmitters rather than just dialing back the daytime flamethrower; this allows plenty of time for maintenance with no interruptions to programming.

If you enjoy old broadcast gear, the tour of this transmitter, which has been rebuilt for use in the ham bands, will be a real treat. Feast your eyes on those lovely old bakelite knobs and the Simpson and Westinghouse meters, and picture a broadcast engineer in white short sleeves and skinny tie making notations on a clipboard. The transmitter is just as lovely on the inside — once the plate power supply is shut down, of course, lest [Mr. Carlson] quickly become [the ~~former~~ late Mr. Carlson] upon stepping inside. Honestly, there aren’t that many components inside, but what’s there is big – huge transformer, giant potato slicer variable caps, wirewound resistors the size of paper towel tubes, and five enormous, glowing vacuum tubes.

It’s a pretty neat bit of broadcasting history, and it’s a treat to see it so lovingly restored. [Mr. Carlson] teases us with other, yet larger daytime transmitters he has yet to restore, and we can’t wait for that tour. Until then, perhaps we can just review [Mr. Crosley]’s giant Cincinnati transmitter from the 1920s and wait patiently.

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VCF: Popular Electronics And Southwest Technical Products Corporation

April 5, 2017 by Brian Benchoff 35 Comments

Hackaday owes a lot to the hobbyist electronics magazines of yesteryear. Back in the day, Popular Electronics and Radio-Electronics would publish projects and articles about DIY electronics – more or less the same editorial purview we hold today. Some of these projects would become full-fledged products, and you need only look at the Altair for what can happen at this confluence of publishing and engineering.

One of the more popular companies to come out of these hobbyist trade magazines was SWTPC, or Southwest Technical Products Corporation. This was the company that brought one of the first microcomputers to the masses with the SWTPC 6800. This wasn’t just a homebrew microcomputer company – there were Nixie clocks, test gear, and stereo preamplifiers – all things that could easily find a place on the pages of Hackaday today.

This year at the Vintage Computer Festival East, [Michael Holley] brought out the test gear he’s been collecting for the past few decades. These are machines that wouldn’t be out of place on any DIY electronics blog today. This is by all accounts the pre-history of the maker movement.

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The Other Way To Brick A Mac Classic

April 5, 2017 by Dan Maloney 7 Comments

Why would you build a mini Mac Classic using LEGO and a Raspberry Pi? Well, why wouldn’t you?

[Jannis Hermanns] couldn’t find a reason to control this outburst of nostalgia for the good old days of small, expensive computers and long hours spent clawing through the LEGO bin to find The Perfect Piece to finish a build. It turns out that the computer part of this replica was the easy part — it’s just an e-paper display driven by a Raspberry Pi Zero. Building the case was another matter, though.

After a parti-colored prototype with whatever bricks he had on hand, a session of LEGO Digital Designer led him to just the right combination of bricks to build an accurate case, almost. It turns out that the stock selection of bricks in LDD won’t allow for the proper proportions for the case, so he ordered the all-white bricks and busted out the Dremel. LEGO purists may want to avert their eyes from the ABS gore within, but in the end the case worked out and the whole build looks great.

Fancy a full-size Mac Classic reboot? How about this iPad docking station? Or if tiny and nostalgic is really your thing, this retro-future terminal build is pretty keen too.

[via r/raspberry_pi]

Project 54/74 Maps Out Logic ICs

April 4, 2017 by Lewin Day 4 Comments

Integrated circuits are a fundamental part of almost all modern electronics, yet they closely resemble the proverbial “black box” – we may understand the inputs and outputs, but how many of us truly understand what goes on inside? Over the years, the process of decapping ICs has become popular – the removal of the package to enable peeping eyes to glimpse the mysteries inside. It’s an art that requires mastery of chemistry, microscopy and photography on top of the usual physics skills needed to understand electronics. Done properly, it allows an astute mind to reverse engineer the workings of the silicon inside.

There are many out there publishing images of chips they’ve decapped, but [Robert Baruch] wants more. Namely, [Robert] seeks to create a database of die images of all 5400 and 7400 series logic chips – the eponymous Project 54/74.

These chips are the basic building blocks of digital logic – NAND gates, inverters, shift registers, decade counters and more. You can build a CPU with this stuff. These days, you may not be using these chips as often in a production context, but those of you with EE degrees will likely have toyed around a few of these in your early logic classes.

There’s only a handful of images up so far, but they’re of excellent quality, and they’re also annotated. This is a great aid if you’re trying to get to grips with the vagaries of chip design. [Robert] is putting in the hard yards to image as many variations of every chip as possible. There’s also the possibility of comparing the same chip for differences between manufacturers. We particularly like this project, as all too often manufacturing techniques and technologies are lost and forgotten as the march of progress continues on. It looks like it’s going to become a great resource for those looking to learn more about integrated circuit design and manufacture!

VCF East: Enigma Machines In The Flesh

April 3, 2017 by Brian Benchoff 13 Comments

At the end of World War II, the Germans ordered all Enigma cipher machines destroyed. Around the same time, Churchill ordered all Enigma cipher machines destroyed. Add a few decades, neglect the efforts of Polish codebreakers, and make a movie about Alan Turing and an offensively historically incorrect love interest, and you have a mystique around these rare, innovative cipher machine.

At the Vintage Computer Festival East, I was privy to what is probably the largest collection of Enigma machines on the planet. The exhibit comes from [Tom] and [Dan Perera] of Enigma Museum. Right now, they’re they only place where you can go out and simply buy a real, wartime Enigma machine. The price? Well, there is a pair of million-dollar Apple I boards at VCF. The Enigmas go for about a fifth of an Apple I.

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Command Alexa With A Completely Mechanical Vintage Remote Control

April 2, 2017 by Cameron Coward 10 Comments

Anyone with grandparents already knows that in ye olden days, televisions did not have remote control. Your parents probably still complain about how, as children, they were forced to physically walk over to the TV in order to switch between the three available channels. In these modern times of technological wonder, we have voice control, programmable touch screen remotes, and streaming services that will automatically play an entire season of the show you’re binge watching. However, before these, and before the ubiquitous infrared remote, television manufacturers were experimenting with ways to keep kids from having to run across the living room every time the channel needed to be changed.

Early remote controls were simply wired affairs — nothing too surprising there. But, it wasn’t long before methods of wireless control were being introduced. One early effort called the Flashmatic would shine light onto a photoelectric cell on the television set to control it. Of course, it might also be controlled by unintended light sources, and users had to have good aim to hit the sensor. These issues soon led to the introduction of the Zenith Space Command remote control, which used ultrasonic frequencies to control the TV.

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