Rebuilding a 1940s TV

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There’s a lot of cool stuff to be found under piles of trash in an antique store. [dijt] discovered this when he found a tiny 7″ Motorola television from the 1940s under a stack of trinkets from earlier eras. We can understand [dijt]‘s impulse buy, and the trials of rebuilding this ancient TV more than qualifies it as a hack.

If you know where to look, there are hundreds of resources available for old televisions, Hi-Fis, and radio equipment from the dawn of the electrical era to the modern day. After consulting with a few forums, [dijt] got his hands on a schematic for his television set and began work on diagnosing what was wrong with it.

It turned out the original ballast tube in this set had long since given up the ghost. Luckily, this is a common problem in old TVs, and after consulting some forums [dijt] had a schematic to replace this ballast tube with some newer caps and resistors.

After constructing the circuit and testing it out, [dijt] mounted it in the old ballast tube to replicate the original look and feel of the 1949 television. Interestingly, this is the second time this TV had been restored; the 1960s-era caps and resistors told [djit] this TV had once went into a television repair shop. Let’s just hope [djit] remembered to glue the schematics to the inside of the chassis this time.

HDTV antenna of a different color

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We’ve seen our share of commercially available HDTV antennas that work really poorly. For at least four years now we’ve gone without cable television, using a coat hanger antenna we made ourselves to record over-the-air broadcasts. But it’s a pretty ugly beast — we’re lucky enough to have an attic in which it can be hidden. If you’re in need of free television and don’t want an eyesore of a an antenna try building this foil and cardboard version. Even it if doesn’t work at all you’re only out about ten bucks.

The expensive part is the matching transformer which converts screw terminals to a coaxial cable connection so that it may be connected to your HDTV. You’ll need a few nuts and bolts, but we assume you can beg, borrow, or steal the tin foil, cardboard, and glue that round out the parts list. Glue, measure, cut, fold, fasten, finished! You’ll be watching horrible summer TV in no time!

If it doesn’t perform as expected just reuse that connector and try your luck with a fractal antenna.

Chromebook hack controls your television

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[Michael Kohn] only accomplished about half of what he set out to, but we still think his TV channel switcher from a Chromebook turned out nicely. When starting the project he wanted to include a grid of listing so that he could choose a specific program, but decided that scraping the data was too much work for this go-round.

The Chromebook doesn’t include an IR transmitter so he built one using an MSP430 chip. He had previously built a little transmitter around an AVR chip and was surprised to find that the internal oscillator on that was quite a bit more accurate than on the MSP430. Timing is everything with the Manchester encoded signals used for IR remote controls so he used his oscilloscope to tune the DCO as accurately as possible.

The app shown on the screen was written in Javascript. Google published some example code on using RS232 with the computer; [Michael] used this resource to provide communications between the computer and the microcontroller.

[Read more...]

Ask Hackaday: Hacking lingo fails

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Ah, CSI. What other television show could present digital forensics with such two-bit dialogue?

It’s time once again to put on your hacker hats – a red fedora, we guess – and tell us the worst hacker dialogue you’ve seen in movies or TV. We’ve seen a ton of shows and movies where writers and directors spend zero time doing any sort of research in whatever technology they’d like to show off in the story they’re trying to convey. Usually this results in lines like, “I’ll create a GUI interface using Visual Basic. See if I can track an IP address.” It’s technobabble at its best, and horribly misinformed at its worst.

We’re wondering what you, the readers of Hackaday, think are the worst examples of hacker lingo fails. Anything from, ‘Enhance!’ to the frightening real-life quote, “the Internet is not a big truck. It’s a series of tubes.”

We’ll compile your suggestions in a later post, but I’m betting something from Star Trek: Voyager will make the #1 technobabble/hacking lingo fails. There’s just too much in that show that isn’t internally consistent and doesn’t pay any heed to the laws of (fictional) physics. Warp 10, I’m looking at you. Of course there was the wonderful Habbo reference in last week’s Doctor Who, but I’m betting that was intentional as [Moffat] seems pretty up to speed on the tropes and memes of the Interwebs.

About a month ago, we asked you for your take on the worst hacking scenes ever shown on TV or film. The results made for good viewing, albeit with a surprising absence of Lawnmower Man. Now we want some dialogue to go with these horrendous hacking scenes. So, what say you, Hackaday? What are the worst hacking lingo fails you’ve seen or heard? Please be specific about what movie/TV show you’re referencing. Last time some good stuff probably slipped by because people just said a few words without context assuming we’d know exactly what they were referring to.

Automatic volume control puts the kibosh on loud TV commercials

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If you’re having a hard time tuning out those loud commercials why not let your electronics project do it for you? This is an Arduino-based setup which adjusts television volume when it goes above a certain threshold. It uses a microphone, rather than a direct audio signal, so you can set it based on what is actually heard in the room.

The control scheme uses the IR LED and IR receiver seen on the breadboarded circuit above. The receiver lets you teach your volume up and down buttons from your remote control to the system. The one failing we see in the design is that the volume level is hard-coded, requiring you to flash new code to make adjustments (perhaps an enterprising reader could add a potentiometer for making easy adjustments?).

We can’t help but be reminded of the setup which reads the closed caption info to mute topics you’ve added to a blacklist.

Scavenged tube television makes a nice fish tank

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[McCaulsey] found an old TV waiting for garbage pick-up on the side of the curb. He brought it home and gave it a new life as an aquarium.

His technique is a little rough, but the finished look is exactly what he was going for. He picked up the cheapest aquarium set he could find at the pet store. It just happens to have a curved front to it which helps to recreate the look of the original CRT. After removing most of the electrical components he went to work on the plastic fins that were used to mount them. Having somehow misplaced his Dremel tool the work was done with a drill and a 1/4″ paddle bit.

Once the demolition was over he started the rebuild by placing a backer in the tank. This is an underwater image that will save him from having to look at the inside of the TV case through the water. A piece of Styrofoam was used as a base to properly frame the front of the tank. The only thing we can’t tell from the build album is how he will manage to feed the fish without taking everything apart again.

[via Reddit]

Decades old TV gets sleep function thanks to 7400 family of chips

[Viktor] dredged up a hack he pulled off years ago. His grandfather likes to end the day in front of the TV, but he falls asleep soon after sitting down. Rather than tick away the electricity meter all night, [Viktor] built an automatic shutoff which is akin to a modern TV’s sleep feature.

At the time microcontrollers were not as easy to source as they are now. So [Viktor] used a circuit based on the 7400 family of logic chips. It uses a multivibrator to feed some binary counter chips. These are used to divide the oscillations to establish the desired timing. He tuned the system to be about 15 minutes, but that can be adjusted using a potentiometer built into the multivibrator. When time is about the run out an LED next to the TV comes on. This way if [Viktor's] grandfather is still awake he can press a button next to his chair to reset the counter. But if he’s already snoozing the counter will eventually switch off the television.