Antique Army Surplus Receiver Restored

June 13, 2020 by Al Williams 16 Comments

If you’ve ever been to a hamfest in the United States, you probably have at least seen an ARC 5 Command set. These were very rugged receivers and there were a ton of them made. Hams have been reworking them for years. In a recent video [Tom N3LLL] shared some of his tips for restoring them.

You might think these are just like a regular old radio, but there are some unique challenges, including capacitors filled with beeswax and strange threaded screws. [Tom] made several custom boards to replace the dynamotor with a solid-state inverter, replace odd capacitors, and provided a faceplate. He also 3D printed some replacement studs to replace the often decayed anti-vibration studs for the dynamotor.

The teardown at the end shows how rugged these things are. Tom’s restoration philosophy is to modernize the set while keeping the outward aesthetics. The receivers perform well, and as you might expect are built like tanks.

If you want to try your hand at restoration, these are not very expensive because there were so many of them made. Often the shipping is about the same price as the radio, but one in good shape can cost a bit more. We think the real fun is getting one that is not in such good shape and making it better.

Everyone has their own style and we know some restorers are more purists, but as a practical matter, [Tom’s] restorations look great, sound great, and preserve these great old radios so that someone might still be using them in another 75 years.

We’ve covered the ARC 5 before, unsurprisingly, and that restoration was a bit more traditional if you prefer it that way. If you need something to listen to on the AM band, try a matching transmitter.

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How CERN Made High Quality Electronics In The 1970s

June 12, 2020 by Jenny List 36 Comments

We’re suckers for some retro electronics here at Hackaday, so we were fascinated when Daniel Valuch wrote to us with some pictures of his findings in his CERN lab’s archive. He works on Linear Accelerator 3, which has had an extended downtime after many decades of continuous operation, for major upgrades and overhauls. Part of the upgrade involves the removal of electronic assemblies dating back as far as the 1970s, and he’s shared his fascination with them as he trawls through dusty filing cabinets in the lab basement.

What it reveals is a world before the CAD and microcontrollers we know, instead here are circuits using the electronic building blocks of logic gates, discretes, and op-amps. PCBs are laid out not with the KiCad that CERN are famous in our community for today, but on acetate, with transfers and tape. A ground plane is even hand-carved from a red sheet. Oddly though it isn’t a world without CNC, because in the pouch with a design from 1974 is a roll of punched paper tape. If you have ever pondered the “Numerical” in “Computer Numerical Control”, here are the numbers in physical form.

For those of us who were trained in this type of electronic design, the convenience of a PCB CAD package and a professionally-made PCB at the click of a mouse is nothing short of miraculous. But seeing personally laid boards of this quality reminds us that seeing the hand of the designer in them is something few engineers today (with the possible exception of Boldport) manage to recreate.

An Open Hardware Modem For The Modern Era

June 9, 2020 by Tom Nardi 39 Comments

Readers of a certain age will no doubt remember the external modems that used to sit next to their computers, with the madly flashing LEDs and cacophony of familiar squeals announcing your impending connection to a realm of infinite possibilities. By comparison, connecting to the Internet these days is about as exciting as flicking on the kitchen light. Perhaps even less so.

But while we don’t use them to connect our devices to the Internet anymore, that doesn’t mean the analog modem is completely without its use. The OpenModem by [Mark Qvist] is an open hardware and software audio frequency-shift keying (AFSK) modem that recalls some of the charm (and connection speeds) of those early devices.

It’s intended primarily for packet radio communications, and as such is designed to tie into a radio’s Push-to-Talk functionality with a standard 3.5 mm jack connector. Support for AES-128 encryption means it will take a bit more than an RTL-SDR to eavesdrop on your communications. Though if you’re really worried about others listening in, the project page says you could even use the OpenModem over a wired connection as you would have in the old days.

If you just want a simple and reliable way to get a secure AFSK communication link going, the OpenModem looks like it would be a great choice. But more than that, it offers a compelling platform for learning and experimentation. The hardware is compatible with the Arduino IDE, so you can even write your own firmware should you want to spin up your own take on this classic communications device.

The OpenModem is the evolution of the MicroModem that [Mark] developed years ago, and it’s clear that the project has come a long way since then. Of course, if you’re more about the look than the underlying technology, you could always just put a WiFi access point into the case of an old analog modem.

[Thanks to Boofdas for the tip.]

Inputs Of Interest: ErgoDox Post-Mortem

June 2, 2020 by Kristina Panos 18 Comments

In the last installment, I told you I was building an open-source, split, ortholinear keyboard called the ErgoDox. I’m doing this because although I totally love my Kinesis Advantage, it has made me want to crack my knuckles and explore the world of split keyboards. Apparently there are several of you who want to do the same, as evidenced by your interest in the I’m Building an ErgoDox! project on IO. Thank you!

Well boys and girls, the dust has settled, the soldering iron has cooled, and the keycaps are in place. The ErgoDox is built and working. Now that it’s all said and done, let me tell you how it went. Spoiler alert: not great. But I got through it, and it keyboards just like it’s supposed to. I’m gonna lay this journey out as it happened, step by step, so you can live vicariously through my experience.

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Build Your Own Dial-Up ISP – Now With Modem Pool!

May 30, 2020 by Lewin Day 54 Comments

When it was the only viable option, the screech and squeal of dial-up internet was an unwelcome headache to many. But now that its time has passed, it’s gained a certain nostalgia that endears it to the technophiles of today. [Doge Microsystems] is just one such person, who has gone all out to develop their very own dial-up ISP for multiple clients.

The retro network is based on an earlier single-device experiment, with a Raspberry Pi 3B acting as the dial-up server. It’s hooked up to four modems, three of which are connected over USB-serial adapters implementing hardware flow control.

Obviously, four analog phone lines are hard to come by in this day and age, so [Doge] uses Asterisk along with a series of Linksys SIP devices to create their own PBX network. Each modem gets a phone line, with four left over for clients to dial in.

To connect, users can either call a certain modem directly, or dial a special number which rings the whole pool. Thanks to mgetty, each modem is set up to answer on a different number of rings to allow the load to be shared. Once connected, a PPP daemon handles connecting the user to the Internet at large.

While it’s unlikely we’ll all be ringing [Doge]’s house to get our next YouTube fix, owning your own dial-up ISP is certainly an admirable feat. We’d love to see it deployed in the field sometime, perhaps at a hacker conference or Burning Man-type event. Of course, if you’ve got your own old-school network pumping data, be sure to let us know! Video after the break.

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Telco Curio Hacked Into Simple Counter

May 26, 2020 by Lewin Day 6 Comments

The tikkenteller was a device used to measure the duration of telephone use. 70 Volts were sent down the telephone line at 50Hz to run an electromechanical counter, and the devices were often used in communal areas where several users shared a single phone. [Charles Babbadge] decided to repurpose the stout 1950s hardware into a simple counter.

The build uses an ATtiny13 to generate pulses for the original hardware, when receiving inputs from the tikkenteller’s buttons. A solid state relay is triggered by the microcontroller, which connects the original solenoid to mains power to jog the counter. An HLK-PM01 5V power supply is used to run the micro, allowing the entire project to run off a single mains supply.

It’s a big, heavy, beautiful hunk of metal, built in a style that we simply don’t see anymore. It’s in no way the cheapest or most efficient counter you could build, but it’s got a charm you can’t find on more modern hardware. You could use such a device to track your Youtube subs, that is… if the API hadn’t broken that for everyone. Video after the break.

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Breathing New Life Into Old School ThinkPad Keyboards

May 26, 2020 by Tom Nardi 6 Comments

The ThinkPad is generally considered the unofficial laptop of hackerdom, so it’s no surprise that we see plenty of projects focused on repairing and modifying these reliable workhorses. But while we usually see folks working on relatively modern incarnations of this iconic line of computers, this project by [Frank Adams] and [Brian Chan] shows that the hacker’s love affair with the ThinkPad stretches back farther than many might realize.

As explained on the project’s Hackaday.io page, the duo have produced an open hardware board that will allow you to take the keyboard and trackpoint from a late ’90s ThinkPad 380ED and use it as a standard USB input device on a modern computer. According to [Frank], the keyboards on these machines are notable for having full-size keys rather than the “chicklet” boards that are so common today.

Now you may be wondering why this is significant. After all, we’ve seen plenty of projects that hook up an old keyboard to a USB-equipped microcontroller to get them speaking the lingua franca. Well, the trick here is that the trackpoint on these older ThinkPads actually required additional circuitry on the motherboard to function. The keyboard features three separate FPC connections for the matrix, the trackpoint buttons, and the analog strain gauges in the trackpoint itself.

After a considerable amount of reverse engineering, [Frank] and [Brian] have developed a board that uses the Teensy 3.2 to turn this plethora of pins into something useful. In the video after the break, you can see the new composite USB device working perfectly on a modern Windows computer.

It will probably come as little surprise to find that [Frank] is no stranger to hacking ThinkPad keyboards. In 2018 we covered a similar adapter he built for the far more modern T61, which was an absolute cakewalk by comparison.

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