Vintage Telegraph Sounder Clicks Again

April 6, 2017 by Dan Maloney 8 Comments

It’s sad, when you think about it: a retired railroad telegraph operator, who probably once pounded out code at 40 words per minute, with a collection of vintage sounders silently gathering dust on a shelf. [kthrace] decided to do something about that, and built this Morse sender to bring those old sounders back to life.

As archaic as Morse might seem, it’s a life skill, one the 92-year old former brass-pounder for whom this was built was eager to practice again. There are code practice oscillators, of course, but dits and dahs are no substitutes for the electromagnetic clicks and clacks that once filled this old fellow’s days. There’s not much information on the circuit, but it looks like [kthrace] chose a RedBoard to read Morse from an SD card and drive some relays to support up to four sounders; that’ll make a racket! The case is custom made and nicely complements the wood and brass of the J.H. Bunnell and Co. sounder, which still sounds great after all these years.

Test your Morse skills in the video below – copying code is a lot harder from a sounder than from an oscillator. Find yourself in need of practice? We’ve got you covered.

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Ham Goes Nuts For Tiny Transmitter

February 24, 2017 by Dan Maloney 26 Comments

What’s the minimal BOM for a working amateur radio transmitter? Looks like you can get away with seven parts, or eight if you include the walnut. You’ve got to have a walnut.

Some hams really love the challenge of QRP, or the deliberate use of low-power transmitters to provide a challenge to making long-distance contacts. We’ve covered the world of QRP before and noted that while QRP rigs don’t throw a lot of power, it doesn’t mean that they need to be simple. Some get quite complex and support many different modulation schemes, even digital modes. With only a single 2N3904 transistor, [Jarno (PA3DMI)]’s tiny transmitter won’t do much more than send Morse using CW modulation, but given that it’s doing so from inside a walnut shell, we have no complaints. The two halves of the shell are hinged together and hold a scrap of perfboard for the simple quartz crystal oscillator. The prototype was tuned outside the shell, and the 9-volt battery is obviously external, but aside from that it’s nothing but nuts.

We’d love to see [Jarno] add a spring to the hinge and contacts on the shell halves so no keyer is required. Who knows? Castanet-style keying might be all the rage with hams after that.

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A Beautiful Morse Key From A Hard Drive Actuator

December 10, 2016 by Jenny List 19 Comments

Morse code, or CW, is a subject that divides the amateur radio community from top to bottom. For some it’s a faded anachronism, while for others it’s the purest form of the art. With it no longer in significant commercial or military use it is radio amateurs who keep it alive, and those for whom it is a passion devote considerable effort to its continuing use.

With well over a century of history behind it there are a huge array of morse keys available to the CW enthusiast. From vintage telegraph keys through WW2 surplus military keys to sideways “bug” keys and modern boutique handcrafted keys, many operators will amass a collection for the love of it, and regularly use them all.

Just one of the hand-drawn illustrations for this project.

Other operators create their own keys, either crafting them from raw materials or using whatever materials they have at hand. Keys have been made from every conceivable piece of junk that will conduct electricity, and made contacts to all parts of the world.

[H. P. Friedrichs, AC7ZL] has produced such a home-made key from surplus material, but it has nothing of the junkbox about it. He’s used the head actuator from a surplus hard drive as the arm of a straight key, and the result is an item of beauty. The actuator bearing is the pivot point, and the business end of the key replaces the hard drive’s heads. The spring is provided by the repulsive force between magnets, the connection at the rear is provided by a piece of guitar string, and the contacts themselves are taken from a surplus power relay. Even his write-up is a thing of beauty, a compelling read with hand-drawn illustrations. If you are not a Morse enthusiast it’s still an engaging project.

We’ve featured many keys here over the years, and this isn’t the first one using a hard drive actuator, as this mint tin paddle shows. Among others we’ve linked you to a collection of unorthodox keys, and of course shown you a vintage telegraph key with a Raspberry Pi decoder.

The Michigan Mighty-Mite Rides Again

January 29, 2016 by Dan Maloney 12 Comments

One of the best things about having your amateur radio license is that it allows you to legally build and operate transmitters. If you want to build a full-featured single-sideband rig with digital modes, have at it. But there’s a lot of fun to be had and a lot to learn from minimalist builds like this Michigan Mighty-Mite one-transistor 80-meter band transmitter.

If the MMM moniker sounds familiar, it may be because of this recent post. And in fact, [W2AEW]’s build was inspired by the same SolderSmoke blog posts that started [Paul Hodges] on the road to his breadboard and beer can build. [W2AEW]’s build is a bit sleeker, to be sure, but where the video really shines is in the exploration and improvement of the signal quality. The basic Mighty-Mite outputs a pretty dirty signal – [W2AEW]’s scope revealed 5 major harmonic spikes, and what was supposed to be a nice sine wave was full of divots and potholes. There’s only so much one transistor, a colorburst crystal and a couple of capacitors can do, so the video treats us to an explanation of the design of the low-pass filter needed to get rid of the harmonics and clean up the output into a nice solid sine wave.

If your Morse skills aren’t where they should be to take advantage of the Might-Mite’s CW-only mode, then you’ll need to look at other modulations. Maybe a tiny FM transmitter would suit your needs better?

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Hacklet 69 – Morse Code Projects

August 7, 2015 by Adam Fabio 10 Comments

With over 160 years of history under its belt, Morse code is by far the oldest digital signaling system known to man. Originally developed for telegraph systems, [Samuel Morse’s] code has been sent over wires, via radio, and even with flashes of light. Hackers, makers and engineers have been working with Morse code throughout history. For many years, simple code keys and practice oscillators were the “hello world” of hobby electronics. In fact, a company which started out selling a Morse key has gone on to become one of the largest electronic component distributors in the world. The company still bears the name of that project: Digi-Key. This week’s Hacklet is all about some of the best Morse code projects on Hackaday.io!

We start with [voxnulla] and Morse key HID + ugly hack. [voxnulla] found an old key at his favorite thrift store. It was dusty, greasy, and for some reason had been painted hospital green. Once the paint and grime were removed, and the original wooden plate restored, the key actually looked pretty good. [Voxnulla] then decided to turn it into a USB Human Interface Device (HID), emulating the keyboard of his computer. An Arduino converts Morse code characters tapped at the key into keystrokes over USB. As [voxnulla] knows, when butterflies aren’t available, real programmers drive vim with a Morse key!

Next up is [Voja Antonic] with Daddy, I don’t have the key. If you didn’t read [Voja’s] article about Hacking the Digital and Social System, check it out! Many apartments have an intercom system where you have to “buzz” someone in, activating a solenoid lock in the door. [Voja] inserted a Microchip PIC12 series microcontroller between the speaker and the unlock button. All a user has to do is tap out the right Morse code password on the call button in the lobby. If the code is accepted, the PIC unlocks the door, and you’re in!

[kodera2t] took things into the digital age with Stand-alone Tiny Morse code encoder/decoder. This project grew out of his general purpose Portable tiny IoT device project. [kodera2t] rolled his own Arduino-compatible board for this project. The tiny ATmega1284 powered computer allows him to encode and decode Morse code. A smartphone-sized keyboard and a lilliputian OLED display serve as the user interface, while rotary encoder allows for variable code speed. You can even “tap” Morse out on one of the tactile buttons!

Finally, we have [Yannick (Gigawipf)] with Portable (morsing) 100W led flashlight. 100 watt LEDs have gotten quite cheap these days, and they’re perfect when you absolutely, positively have to blind everyone around you. These LEDs can also be switched on and off quickly, which makes them perfect for Morse code. In years past, mechanical shutters had to be used to perform the same feat. [Yannick] used a 5000mAh 5S Zippy Li-Po to supply electrons to this hungry beast, while a 600 Watt constant current boost converter keeps that power under control. An Arduino running Morse code converter software controls the boost convert and LED. [Yannick] uses his computer to send a message over the Arduino’s serial link, and the light does the rest, flashing out the message for all to see.

If you want more Morse goodness, check out our brand new Morse code project list! My Morse is a bit rusty, so if I wasn’t able to copy your transmission and missed your project, don’t hesitate to drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Converting Morse Code To Text With Arduino

February 10, 2015 by Rick Osgood 34 Comments

Morse code used to be widely used around the globe. Before voice transmissions were possible over radio, Morse code was all the rage. Nowadays, it’s been replaced with more sophisticated technologies that allow us to transmit voice, or data much faster and more efficiently. You don’t even need to know Morse code to get an amateur radio license any more. That doesn’t mean that Morse code is dead, though. There are still plenty of hobbyists out there practicing for the fun of it.

[Dan] decided to take a shortcut and use some modern technology to make it easier to translate Morse code back into readable text. His project log is a good example of the natural progression we all make when we are learning something new. He started out with an Arduino and a simple microphone. He wrote a basic sketch to read the input from the microphone and output the perceived volume over a Serial monitor as a series of asterisks. The more asterisks, the louder the signal. He calibrated the system so that a quiet room would read zero.

He found that while this worked, the Arduino was so fast that it detected very short pulses that the human ear could not detect. This would throw off his readings and needed to be smoothed out. If you are familiar with button debouncing then you get the idea. He ended up just averaging a few samples at a time, which worked out nicely.

The next iteration of the software added the ability to detect each legitimate beep from the Morse code signal. He cleared away anything too short. The result was a series of long and short chains of asterisks, representing long or short beeps. The third iteration translated these chains into dots and dashes. This version could also detect longer pauses between words to make things more readable.

Finally, [Dan] added a sort of lookup table to translate the dots and dashes back into ASCII characters. Now he can rest easy while the Arduino does all of the hard work. If you’re wondering why anyone would want to learn Morse code these days, it’s still a very simple way for humans to communicate long distances without the aid of a computer.

A Wireless Web-Connected Morse Code Keyer

January 20, 2015 by Ethan Zonca 10 Comments

[Kevin] recently scored a Morse code keyer/sounder unit from the 1920s on eBay. While many hams would love to use an old keyer for CW, [Kevin] took a different route and repurposed it into a wireless web-connected morse code keyer.

[Kevin] mounted an Arduino Yun under the keyer, which listens for user input and provides web connectivity. The Yun connects to [Kevin]’s open-source web API he calls “morsel,” which allows it to send and receive messages with other morsel users. When a message is keyed in, the Yun publishes it to the API. When another keyer queries the API for incoming messages, the Yun downloads the morse sequence and replays it on the sounder.

[Kevin] also added some copper electrodes to the top of his enclosure, which act as capacitive buttons while keeping the keyer’s old-school appearance. The left button replays the most recently received message, and the right button sets the playback speed. Check out the video after the break to hear and see the keyer in action.

Thanks for the tip, [Jarrod].

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