The making of a Vacuum Tube

With the death of Heathkit looming  in our minds it’s high time for a a heartwarming story. [Ronald Dekker] has done a wonderful job documenting the history of the E1T beam counting tube, detailing everything from the work led up to the invention of the tube to the lives of the inventors themselves.

For those who are unaware, the E1T is a rather strange vacuum tube capable counting from 0 to 9. While that’s nothing too special in itself, the tube also displays the numbers on a phosphor screen, much like a miniature cathode ray tube. In fact, this phosphor screen and the secondary emission caused by it is critical to the tubes operation. To put it bluntly, it’s a dekatron and a magic eye tube smashed together with the kind of love only a group of physicists could provide.

Now, who wants to have the honor of transposing Ronald’s story into a wikipedia article?

Hackaday Links: December 25, 2011

Ah, Christmas. That wonderful time of year when you can roll out of bed to the screams and wails of children, grab a hot cocoa, and spend several hours arguing with an 8-year-old about which LEGO set to build first. Simply magical. While you’re waiting for the Doctor Who Christmas special to come on, settle down with these wonderful Christmas-themed builds that came in over the last few weeks.

One step closer to Robot Santa

Here’s an interesting way to spice up your seasonal headwear. [Mark] took a Santa hat and added a string of multicolored LEDs to the brim. The lights were picked up at a drug store for a dollar. Control is through a simple push button connected to an ATtiny13. Press the button, the lights cycle in a different pattern. Very cool, so check out the video.

A holographic holiday tree

[Auger] posted this very cool light up Christmas tree decoration on Instructables. This tree is made up of three pieces of acrylic. Different designs were laser cut into each piece of plastic – candy canes for the ‘red’ piece, stars and tinsel for the ‘yellow’ piece, and the tree for the ‘green’ piece. LEDs of the respective colors are cemented to the bottom of each bit of plastic. It’s called light piping and is used everywhere. This is the first time we’ve seen three colors, though.

This is what nerds do, and it’s awesome

[Rickard Dahlstrand] was playing around with his phone trying to take deliberately fuzzy pictures of his tree. He noticed the dashes produced from the LED Christmas lights must be produced from PCM dimming. Going through the EXIF data in the picture, he found the exposure time was 1/17th of a second. 1/17 of a second = ~ 58 ms / 5 (cycles on the picture) = ~11 ms per cycle = ~100 Hz frequency on the PCM dimming. Of course this is just about 2 times the line frequency in [Rickard]’s native Sweden, so we’ll call this confirmed. There’s no blog post for this, but we’ve never seen a clearer example of applied geekery. Simply awesome.

Yeah, we measured [Rickard] on a nerd meter

In the spirit of giving, [Johannes] decided to tell the entire world exactly how nerdy he is. He built a ‘Nerd Alert’ meter out of an old 1950s Japanese multimeter. The old guts of the meter were chucked, and a simple amp made out of a transistor amplifies the current flowing through the user’s fingers. A neat scale ([Johannes] measures somewhere between Amiga Workbench and Space invaders) replaces the old, boring, number-based one. Again, no write-up, but here’s some awesome build pictures.

Finally a use for all those old radio tubes

[AUTUIN] took apart a vacuum tube with a blow torch and a diamond cutting wheel. Surprisingly, he was able to put it back together, but not before making a wonderful Christmas ornament. There are two copper wires inside the envelope that are the leads to a single orange-red LED. The whole thing is powered by a watch battery. We’ll be sure to reference [AUTUIN] next time we have to take apart a glass bulb, because he managed not to burn, cut or blind himself.

Six things in a links post? It’s a Christmas miracle!

[Darryl] sent in a nice tool to select and display all of the hacker/maker merit badges available from Adafruit. Oh, we’re still trying to figure out who to give 10 badges to. We’re giving away skull ‘n wrench badges to the top ten hacks ever featured here. Leave a note in the comments, or tell us who should win.

Holiday wishes

Now put the computer down and go spend some time with your families, or failing that, strangers. Of course there’s an all day Doctor Who marathon, and that thing isn’t going to watch itself…

Junkyard tube-amp gold!

Why, oh why, oh why do people toss out awesome retro hardware?? Luckily, [Dino] visited the junk depot himself at just the right time. Even though you’re not supposed to take things others have dropped off he poached the retro portable turntable that was just sitting there. He cracked it open and figured out how to turn it into this great tube guitar amp without going to all that much trouble.

The original turntable used to be where the front grates are in the image above. The guitar amp version sits the case on end, which works perfectly since the carrying handle is now on the top. This orientation would have put the amplifier hardware upside down, so [Dino] pulled it out and flipped it around. The speakers for the turntable were made to sit separately and be connected with wires. But they also doubled as a lid for the unit. This makes them the perfect size to fit side-by-side in the void left by the turn table.

[Dino] records his own music for the build video after the break using his new hardware. Sounds great, looks great, and it was saved from being needlessly buried in the ground. Fantastic!

Continue reading “Junkyard tube-amp gold!”

Baking pan tube amp sounds better than you’d expect

baking_pan_tube_amp

A few years back, [Gio] decided to try his hand at building a couple of tube amplifiers.

The first amp was more of an experiment to see how well a DIY single-ended tube amp would sound. The amp is based off the 6T9 design created by Spare Time Gizmos, and incorporates a pair of 6T9 vacuum tubes, hence the name.  He wired things up in an afternoon, then got busy drilling holes in a baking pan, where he mounted the amp. Bear with us for a second, it’s not as bad as it sounds. The amp actually looks pretty good mounted in the dark black steel, and this sort of enclosure is far cheaper than most DIY amp enclosures. He says that he was sure to be extra careful in isolating all of the electronic components from the metal chassis.

The second amp was built to test the performance differences between Pentode-mode and Ultra-Linear mode configurations. While both amps share a substantial amount of the same components, his UL amp benefits from slightly better capacitors and an uprated power supply, not to mention a more conventional case.

Both amps sound great, according to [Gio], but should be paired with efficient speakers for the best experience. He does note that the ultra-linear amp is the better choice, mounting options aside.

[Thanks, Philippe]

[via RetroThing]

Imploding Vacuum tubes for science

The researchers at Brookhaven National Laboratory are looking for a way to harden photomultiplier tubes. In order to make a more durable tube the researchers decided it would be a good idea to first observe how the tubes are failing. So they got their hands on an old torpedo test bay and smashed some bulbs inside of it. Check in after the break for some high fps bulb smashing.

Photomultiplier tubes are used in massive quantities to detect the highly elusive neutrino particle. The problem is when you have 50,000 photomultipliers submerged in pressurized water the the collapse of just a single bulb can cause a shock wave of destruction. This is what happened in japan in 2001 when a maintenance worker unknowingly compromised a single bulb in a 11,000 bulb array. When the tank was repressurized that single compromised bulb caused them to lose 7,000 more.

[via wired]

Continue reading “Imploding Vacuum tubes for science”

Guitar tube-amp from junk hi-fi

[Tristan Chambers] picked up an old speaker box some friends acquired at a yard sale. It didn’t have any inputs, and there weren’t any tuning knobs like a radio would have, so it’s a mystery what this was originally used for. [Tristan] traced out the circuit and figured out where he could input audio signals which allowed him to hook up an iPod, but it was mono and not very loud. He ended building his own vacuum tube preamp from a schematic he found on the Internet so that he could use it with an electric guitar. As the video after the break shows, the box not only puts out some pretty good sound but it’s nice and loud too.

Continue reading “Guitar tube-amp from junk hi-fi”

VFD as a sound amplifier

[Alessandro Lambardi] had some vacuum flourescent displays that he pulled from junked VCRs. His latest project is an experiment to use one of the VFDs as a headphone amplifier. This means he’s trying to use them as vacuum triode amplifiers, aka vacuum tubes. He did get it to work but as he suspected, the output is fairly low power. It may be possible to use this setup as a preamp and build an actual tube amp to use along with it.

Update: Thanks to [Fallen] for mentioning that we’ve covered this concept in the past.

[Thanks Muris]