When the Regency TR-1 transistor radio came out onto the market in the 1950s, it was hailed as a modern marvel of microelectronics. With only four transistors and a handful of other components, the TR-1 was a wonder of modern engineering. [Sprite_tm] may have those old-timers beat, though. He built an FM transmitter with the lowest parts count of any transmitter ever.

Like most of [Sprite_tm]‘s builds, it’s an unimaginably clever piece of work. [Sprite] overclocked the internal RC oscillator of an ATtiny45 to 24 MHz. After realizing the PLL running at four times the frequency of the oscillator was right in the middle of the FM band, he set about designing a tiny FM transmitter.

[Sprite_tm] remembered his work on MONOTONE and made a short song for hit ATtiny. The firmware for the build takes the notes from his song and varies the 96 MHz PLL frequency a tiny bit, thereby serving as a tiny FM transmitter.

Does it work? Well, if you want to compare it to a Mister Microphone, the range is incredibly limited. That being said it works. It’s an FM transmitter built out of a microcontroller and a battery, and that’s very impressive. Check out [Sprite_tm]‘s demo after the break.

[Bradley]‘s workplace was recently put into a position where they needed to install a WIFI network to operate some wireless barcode scanners, which was left open for anyone to connect to. Management thought that the people in the shop, who didn’t really need internet, would get less work done if they had access to it. So they just simply stuck the access point as far away as they could. Problem with that theory is that the signal still reaches a little bit where they don’t want it, and people in the shop really want access, so a repeater is needed.

Of course this repeater cant be just sitting out in the open. so [Bradley] decided to hide the it inside of an old radio. Searching around he finally settled on a 10$ ebay radio from the 1980′s, which is large enough to hold the guts of a WRT54G. The routers AC adapter was popped open and wired into the AC input of the radio, the main board and antennas were epoxied to the back. Once everything is buttoned back up you’re left with a hidden repeater, and a fully functional radio.

Now hopefully none of his bosses read his blog!

[Cjmekeel] spent weeks getting his Halloween display ready this year. The centerpiece of his offering is this full-sized motorized skeleton. But there’s a few other gems that he worked on to compliment it. There’s an old-fashioned radio whose dial moves mysteriously and plays a news flash warning of an escaped mental patient. He also spent a couple of dollars to outfit a crow with some glowing red eyes and a servo motor.

But the creepiness of the skeleton means you might not even notice those other props. He started with a rather boring looking plain plastic head and did some real magic to build up the rotting flesh and gaping wounds. Those penetrating eyes don’t hurt either. The head moves on a few servo motors which use random values and sleep periods for disturbingly jerky movements. Check out the video after the break to get a glimpse at what kept kids away from his house on Halloween.

This is just a build log and unfortunately there’s no post yet showing the finished product. If we can get enough information together we’ll try to run a follow-up.

[Thanks Skater_j10]

[Jose] added several features to a Makita AM/FM jobsite radio, and did such a good job that you can’t tell they weren’t originally part of the design. The original radio has a compartment for a battery pack used with Makita’s line of rechargeable tools, and offers AM/FM radio, as well as auxiliary audio playback via a pair of speakers. [Jose] augmented those speakers by adding a pair of tweeters as well.

Next on his list of features were a couple of power bus add-ons. In the image on the right you can see the results of adding an automotive cigarette lighter to the side of the unit. Opposite this you’ll find a pair of USB ports that are activated by a lighted toggle switch. The ports are part of a USB car charger that is patched into the battery with a flip of that switch.

Finally, there’s a built-in Bluetooth audio receiver that connects to the auxiliary input. As shown in the image on the left, he can now play tunes from his cellphone without the need for a cord. See him showing off the device in the video after the break.

[Thomas] wrote in to tell us about his latest project, the “AlarmTock”. Like many hacks, this was inspired by some outdated hardware, a radio alarm clock from 1992.

After finally getting fed up with his old alarm clock, [Thomas'] wife purchased him a new one for around $10 from a local retail store. Although most likely an improvement, [Thomas] wondered why after so many years he still had to listen to either an annoying “beep” sound or whatever song the DJ on the radio decided to play.

In true hacker form, he decided to do something about it. [Thomas] crammed a [Chumby Hacker Board], which has much of the same hardware as the [Chumby One] device, into his clock radio. RSS-driven text-to-speech was used to tell him exactly what he wanted to know every morning. A sample .wav file is provided as well as the python script used to execute his morning wakeup routine. For another fun hack from [Thomas] check out his Google treadmill hack here!

[Autuin] was worried about having desirable electronics stolen while on the road with his band. He didn’t want to take a laptop along on tour, but he didn’t want to be without his music either. To solve this problem, he built a music player inside of a cheap-looking radio. His write-up covers two different portable MP3 solutions, but it’s the second rendition that catches our attention.

After hollowing out the old radio he filled the void with an Asus WL-HDD 2.5. That hardware is meant to be an easy way to add network storage; it houses a laptop hard drive and has WiFi and Ethernet connectivity. But it also has one USB port, and can be hacked to add a second. [Autuin] did just that, using the two USB connections to add a Bluetooth dongle and a USB sound card. Music is synced with the hard drive via some cat-5 cable that’s hidden in the battery compartment of the vintage box. The NAS runs Linux, and the audio playback software is controlled though a Mobile Java application running on a somewhat broken cellphone. That’s an idea that might find its way into our next project.

Normally when we see an R/C transmitter used in a build we’re prepared for robots, quadcopters, or UAVs. [Alex] found a new use for his Futaba radio – hooking it up to his Super Nintendo.

We’ve seen a lot of builds using game controllers as interfaces to other hardware. The N64 media remote comes to mind, as does the NES iPod dock. Outside of a few builds to automatically win in-game currency for you, we haven’t seen much of anything to control a video game with additional electronics. [Alex]‘s build happily bucks that trend, and technically gives the SNES an analog controller.

The build uses an mBed microcontroller to capture the radio’s button and stick positions. This is sent through a two shift registers to produce the 16-bit packet required of the SNES controller protocol. [Alex] posted all the software for his build, and from the looks of it the code seems pretty portable. [Alex] says he’s working on getting his Sega Saturn running with his Futaba, so we can’t wait to see some Panzer Dragoon action. Check out [Alex] demoing his controller with Gradius III after the break.

Interestingly enough, this device is capable of transmitting in the 100KHz to 480KHz frequencies. The AM band goes from 520 KHz to 1610KHz, so in order to hear this signal, one must actually tune the radio to twice the emitted frequency. This allows one to tune into the harmonic frequency and receive a signal in this range.

Using the harmonic frequency to transmit is an interesting concept by itself. Additionally, the idea that one could build this device with or without the kit in the future should appeal to experienced hackers and those just starting out alike. Check out the “AM Singer” prototype video after the break.

[Demetris] sent in a tip about a project he’s working on: an Open Source Remote Control transmitter. This is one of the most impressive looking RC transmitters we’ve ever seen. The OSRC could be great for a small UAV – just get the GPS position from the aircraft and map it with the transmitter’s screen. There’s also support for a video downlink so flying around New York City is possible with a single device.

The transmitter/receiver combo are more actually referred to as transceivers. According to [Demetris], the radios on both the ‘ground side’ and ‘vehicle side’ can talk to each other on a 115 kbps data link on the 2.4GHz band. Sending commands and getting telemetry to something we’ve seen before, but never in a single integrated package. The expected range is in the neighborhood of 10 – 40 km.  The ground unit is based on a Gumstix board and has a 4.8 inch display. This really isn’t so much an RC transmitter but a computer that happens to control RC airplanes.

[Demetris] has had some success doing some professional development with Gumstix boards, so it looks like he has the skills to build a very nice R/C controller.

[Jeri Ellsworth] has been working on a direct conversion receiver using an FPGA as an oscillator and a PC sound card DSP. Being the excellent presenter she is, she first goes through the history and theory of radio reception (fast forward to 1:30), before digging into the meat of the build (parts 2 and 3 are also available).

Instead of ‘old school’ receiving sets, the functionality of a software-based radio can be changed by just modifying the program. Building one of these receivers doesn’t use many parts, but the math and programming behind the radio can be pretty intense. Everything is fed into an off-the-shelf PC sound card for processing. The 16-bit sound card [Jeri] used covers 22kHz of radio bandwidth, but that can be increased to 48kHz with a 24-bit card.

The build itself is just a small circuit that goes between the antenna, but we have to respect [Jeri]‘s ability to deal with that amount of analog madness. There’s also a  great PDF on software-designed radio that [Jeri] linked to explaining everything in a non-youtube format. This receiver is pretty impressive considering we’ve come a pretty long way over the past century.

[Jay Collett] likes listening to Internet radio stations and decided to build his own standalone hardware that lets him listen without being at his computer. But he wasn’t starting from square one on this project. [Jay] built on the epic instruction set that [Mighty Ohm] published when he first built his own WiFi radio.

Both of these radios used the same method of getting onto the internet; a hacked router. We kind of like this because it means you should be able to use the radio as a bridge for wired Ethernet devices. But we digress. [Jay] departs from the instructions by using an Arduino and its IDE to interface an LCD screen with a different line/column orientation than the original, and to implement a different control scheme. This makes the project a bit more approachable if you prefer not to roll your own electronics.

Take a look at the video after the break. The router takes quite a while to boot, but once it does it seems that the controls are both intuitive and responsive.

[Bill Meara] was watching the International Space Station and the Shuttle Discovery pass overhead a few weeks ago, which rekindled an interest he gave up long ago – sending and receiving radio packets from space.

Years ago, he used to send APRS packets into space with a small rig powered by a 286 computer and HandiTalkie. These packets would drift off into space most of the time, but occasionally they would bounce back to Earth whenever the space station or PC Sat would fly by. The packets were often captured by other ham operators across the globe, who happened to be tuned to 145.825 MHz.

His interest renewed, he dug out his old HandieTalkie and Kantronics Terminal Node, aiming them towards the sky via an antenna situated in his back yard. When he returned 10 hours later, he found that he had collected all sorts of “space packets” from across the globe.

While not exactly a hack, it is definitely a neat exercise in ham radio operation. We can imagine slinging data packets off the space station would be an exciting experience for any budding operator (and OMs as well!)

The ChronoTune is a radio that plays sounds from different eras. This project was developed as an entry for the Redbull Creation Challenge by some members of i3Detroit, a hackerspace in the motor city. It allows a user to turn the dial to tune in a new moment in history, but they can also listen in on the present day. They’ll be greeted with the sounds of a tuning radio, followed by music or audio clips common to the period displayed on the dial.

As you know from the last contest entry, each project must use an Arduino to qualify. It reads a rotary encoder attached to one of the knobs on the front of the case. This doesn’t directly move the tuning needle. Instead, it’s attached to the guts of an inkjet printer to move it back and forth. This lets the radio tune itself if need be.

The audio is played from several sources. There is an MP3 module that allows for longer clips, but there are also some ISD voice recorder chip modules that play back shorter clips. If the dial is tuned to present day, an FM radio module tunes in a station over the air.

Having trouble reading that dial? Don’t worry, there’s a simulated Nixie tube display sticking out the top of the case to provide a digital readout of the currently selected time period. Check out the video after the break to see the team walk us through each part of the ChronoTune.

[Thanks Duncan]

Instructables user [knife141] enjoys restoring vintage electronics in his spare time, especially old radios. AM radios tend to pique his curiosity the most, and in this tutorial, he discusses the restoration of an old radio from the early 1940s.

While people would likely assume that the vacuum tubes in a radio this old are the source of poor performance, he has found that most units he repairs suffer from bad capacitors. He says that the old electrolytic, paper, and wax caps used in these radios were never meant to last more than a few decades, let alone 70 years.

He always starts the process off by discharging the caps and replacing the power cord, both as a safety measure. He was pretty sure the capacitors were bad in this radio, so he swapped all of them out, regardless of condition. All of the internal wiring was then checked over, and any damaged cables were replaced or covered with heat shrink tubing.

With that done, he powered on the radio and was happy to find that the distortion he previously experienced was completely eliminated. With the electronics taken care of, he tackled the radio’s asbestos insulation by encapsulating it with varnish. Attention was then turned to the exterior, where he cleaned and buffed the leather, refinished the face plate, and polished the dial’s cloudy glass.

While it’s not exactly a hack, we always like seeing vintage electronics given new life, and we’re always cool with saving these sorts of things from rotting in a landfill.

Instructables user [Jan] likes listening to music while hacking away in his workshop, but listening to the same CDs gets tired and boring after awhile. He contemplated listening to streaming audio over the Internet, but hated the idea of needing a computer around at all times. After a bit of reading, he found some information about building a WiFi radio, and got started on constructing his own.

Using a guide he found at the MightyOhm, he hacked an Asus router to use OpenWRT, adding a music player daemon to tune in various stations. He added a small LCD display and an ATmega32 to drive it, as well as a rotary encoder to allow him to switch between stations.

The case was built using several layers of  MDF which were cut using a CNC mill, and joined together with glue and wooden dowels. The front and back panels were milled out of  alucobond sheets, with the remainder of the case covered in white wood veneer. The detail that went into this build is great, we especially love the “WiFi Symbol” speaker grilles.

All of his code and schematics are available for download, should you desire to make a WiFi radio of your own. Stick around to see a video of his completed radio in action.

[via MightyOhm]