Retrotechtacular: Putting Pictures On The Wire In The 1930s

April 25, 2023 by Dan Maloney 52 Comments

Remember fax machines? They used to be all the rage, and to be honest it was pretty cool to be able to send images back and forth over telephone lines. By the early 2000s, pretty much everyone had some kind of fax capability, whether thanks to a dedicated fax machine, a fax modem, or an all-in-one printer. But then along came the smartphone that allowed you to snap a picture of a document and send it by email or text, and along with the decrease in landline subscriptions, facsimile has pretty much become a technological dead end.

But long before fax machines became commonplace, there was a period during which sending images by wire was a very big deal indeed. So much so that General Motors produced “Spot News,” a short film to demonstrate how newspapers leveraged telephone technology to send photographs from the field. The film is very much of the “March of Progress” genre, and seems to be something that would have been included along with the newsreels and Looney Tunes between the double feature films. It shows a fictional newsroom in The Big City, where a cub reporter gets a hot tip about an airplane stunt about to be attempted out in the sticks. The editor doesn’t want to miss out on a scoop, so he sends a photographer and a reporter to the remote location to cover the stunt, along with a technology-packed photographic field car. Continue reading “Retrotechtacular: Putting Pictures On The Wire In The 1930s” →

Making Neon Trees The Easy Way With No Oven Pumps Required

April 20, 2023 by Lewin Day 26 Comments

Neon lamps are fun and beautiful things. Hackers do love anything that glows, after all. But producing them can be difficult, requiring specialized equipment like ovens and bombarders to fill them up with plasma. However, [kcakarevska] has found a way to make neon lamps while bypassing these difficulties.

[kcakarevska] used the technique to great effect on some neon tree sculptures.

The trick is using magnesium ribbon, which is readily available form a variety of suppliers. The ribbon is cut into small inch-long fragments and pushed into a borosilicate tube of a neon sculpture near the electrode. Vacuum is then pulled on the tube down to approximately 5 microns of pressure. The tube is then closed off and the electrode is heated using an automotive-type induction heater. In due time, this vaporizes the magnesium which then creates a reactive getter coating on the inside of the tube. This picks up any oxygen, water vapor, or other contaminants that may have been left inside the tube without the need for an oven vacuum pumping stage. The tube is then ready to be filled with neon. After about 24 to 48 hours of running, the getter coating will have picked up the contaminants and the tube will glow well.

It’s a useful technique, particularly for complex neon sculptures that won’t readily fit in an oven for pumpdown. If the glasswork is still too daunting, though, you can always use other techniques to get a similar look. Video after the break.

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Neon Lamps — Not Just For Pilot Lights

September 13, 2022 by Dan Maloney 30 Comments

It’s easy to see why LEDs largely won out over neon bulbs for pilot light applications. But for all the practical utility of LEDs, they’re found largely lacking in at least one regard over their older indicator cousins: charm. Where LEDs are cold and flat, the gentle orange glow of a neon lamp brings a lot to the aesthetics party, especially in retro builds.

But looks aren’t the only thing these tiny glow lamps have going for them, and [David Lovett] shows off some of the surprising alternate uses for neon lamps in his new video. He starts with an exploration of the venerable NE-2 bulb, which has been around forever, detailing some of its interesting electrical properties, like the difference between the voltage needed to start the neon discharge and the voltage needed to maintain it. He also shows off some cool neon lamp tricks, like using them for all sorts of multi-vibrator circuits without anything but a few resistors and capacitors added in. The real fun begins when he breaks out the MTX90 tube, which is essentially a cold cathode thyratron. The addition of a simple control grid makes for some interesting circuits, like single-tube multi-vibrators.

The upshot of all these experiments is pretty clear to anyone who’s been following [David]’s channel, which is chock full of non-conventional uses for vacuum tubes. His efforts to build a “hollow state” computer would be greatly aided by neon lamp circuits such as these — not to mention how cool they’d make everything look.

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Frequency Counter Restoration Impeded By Kittens

August 24, 2022 by Al Williams 12 Comments

We think of digital displays as something you see on relatively modern gear. But some old gear had things like nixies or numitrons to get cool-looking retro digital displays. The HP 521A frequency counter, though, uses four columns of ten discrete neon bulbs to make a decidedly low-tech but effective digital display. [Usagi Electric] has been restoring one of these for some time, but there was a gap between the second and third videos as his workshop became a kitten nursery. You can see the last video below.

In previous videos, he had most of the device working, but there were still some odd behavior. This video shows the final steps to success. One thing that was interesting is that since each of the four columns are identical, it was possible to compare readings from one decade to another.

However, in the end, it turned out that the neon bulbs were highly corroded, and replacing all the neon bulbs made things work better. However, the self-check that should read the 60 Hz line frequency was reading 72 Hz, so it needed a realignment. But that was relatively easy with a pot accessible from the back panel. If you want to see more details about the repair, be sure to check out the earlier videos.

We love this old gear and how clever designers did so much with what we consider so little. We hate to encourage your potential addiction, but we’ve given advice on how to acquire old gear before. If you want to see what was possible before WS2812 panels, you could build this neon bulb contraption.

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Neon, Ukraine, And The Global Semiconductor Industry

February 27, 2022 by Jenny List 34 Comments

On our news feeds and TV channels at the moment are many stories concerning the war in Ukraine, and among them is one which may have an effect on the high-tech industries. It seems that a significant percentage of the world’s neon gas is produced in Ukrainian factories, and there is concern among pundits and electronics manufacturers that a disruption of this supply could be a further problem for an industry already reeling from the COVID-related chip shortage. It’s thus worth taking a quick look at the neon business from an engineering perspective to perhaps make sense of some of those concerns.

As most readers will know from their high school chemistry lessons, neon is one of the so-called inert gasses, sitting in the column at the extreme right of the Periodic table. It occurs in nature as a small percentage of the air we breathe and is extracted from the air by fractional distillation of the liquid phase. The important point from the above sentences is that the same neon is all around us in the air as there is in Ukraine, in other words, there is no strategic neon mine in the Ukrainian countryside about to be overrun by the Russian invaders.

So why do we source so much neon from Ukraine, if we’re constantly breathing the stuff in and out everywhere else in the world? Since the air separation industry is alive and well worldwide for the production of liquid nitrogen and oxygen as well as the slightly more numerous inert gasses, we’re guessing that the answer lies in economics. It’s a bit harder to extract neon from air than it is argon because there is less of it in the air. Since it can be brought for a reasonable cost from the Ukrainians who have made it their business to extract it, there is little benefit in American or Western European companies trying to compete. Our take is that if the supply of Ukrainian neon is interrupted there may be a short period of neon scarcity. After that, air extraction companies will quite speedily install whatever extra plant they need in order to service the demand. If that’s your area of expertise, we’d love to hear from you in the comments.

Here at Hackaday we are saddened beyond words at what has happened in Ukraine, and we hope our Ukrainian readers and those Ukrainian hackers whose work we’ve featured make it through safely. We sincerely hope that this madness can be ended and that we can mention the country in the context of cool hacks again rather than war.

If you are interested in the strategic value of inert gasses, have a read about the global helium supply.

Header image: Lestat (Jan Mehlich), CC BY-SA 3.0.

NE-2 neon lamp illuminated side-by-side with non-illuminated

The Humble NE-2 Neon Lamp Has A New Trick

October 24, 2021 by Dave Rowntree 43 Comments

Ah, the humble neon lamp. The familiar warm orange glow has graced the decks of many a DIY timepiece, sometimes in a purely indicating duty, and sometimes forming a memory element in place of a more conventional semiconductor device. Capable of many other tricks such as the ability to protect RF circuits from HV transients, its negative resistance operating region after it illuminates gives us usable hysteresis which can used to form a switching element and the way the pair of electrodes are arranged give it the ability to indicate whether a voltage source is AC or DC. Now, due to some recent research by [Johan Carlsson] and the team at Princeton University, the humble NE-2 tube has a new trick up its sleeve: acoustic transduction.

The idea is not new at all, with some previous attempts at using electric discharge in a gas to detect audio, going back to the early part of last century, but those attempts either used atmospheric pressure air or other non-sealed devices that exhibited quite a lot of electrical noise as well as producing noxious gases. Not ideal.

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The History Of Neon Lights

May 17, 2021 by Al Williams 12 Comments

We always enjoy history videos from [The History Guy] but they don’t always cover technology history. When they do, though, we enjoy them twice as much as with the recent video he posted on the history of neon signs. Of course, as he points out, many neon lights don’t have actual neon in them — they use various noble gasses depending on the color you want. Sure, some have neon, but the name has stuck.

The back part of the video is more about the signs themselves, but the early portion talks about [William Ramsay], a Scot chemist who started extracting component gasses out of the atmosphere. The first one found was argon and then helium. Krypton and neon were not far behind. The other noble gas, Xenon, also fell to his experiments. He and another scientist won the Nobel for this work.

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