radio

568 Articles

Codec2: GNU Low-bitrate Speech Codec

September 23, 2010 by 11 Comments

Low bandwidth speech compression is a desirable concept for amateur radio enthusiasts. Unfortunately there isn’t a great open-source option out there, but that’s changing with the low-bitrate speech compression package called Codec2. It manages to transmit and decode at 2550 bits per second with results comparable to proprietary solutions like MELP and very near the initial goal of 2400 bit/s. [David Rowe], who spearheads the project, has been simulating communications using a Linux box and has posted audio snippets at the first link above for comparison. They’re looking for feedback and testing so if you interested give them a helping hand.

[Thanks Robomo]

Small And Simple FM Radio

September 21, 2010 by 23 Comments

[gpsKlaus] built this little FM radio (translated) based on the AR1010 IC. That chip is controlled via I2C by an ATtiny45 microcontroller. His tuning implementation relies on presetting 16 stations in the firmware and selecting them with the white potentiometer.

The FM chip came on a breakout board from SparkFun. Not bad at around $15 as it includes the crystal, some caps and a few resistors, and you don’t have to try and solder to the fine pitched pads on that minuscule package. We’re a little unsure of the features included in the part as the datasheet is lacking in detail and the reference datasheet that SparkFun includes in the description is obviously for a much more full-featured chip. Still, this would be a fun thing to play around with if you’ve grown tired of blinking LEDs.

If you don’t want to let an integrated circuit do all the heavy lifting try this post for a guide on building your own radio tuner.

1953 Radio Includes Tubes, AM, FM, And MP3

September 7, 2010 by 16 Comments

This vintage radio can play AM, FM, and MP3, all with a classic sound. Inside you’ll find a new AM radio tube-amp, providing the functionality you’d expect from the device. The rest of it comes from a conglomeration of parts; an FM receiver board from another radio and an MP3 player with remote control and USB connector. The classic sound we mentioned above comes from an AM modulator. That’s right, the auxiliary audio boards aren’t connected directly, but are broadcast on the AM band so that your latest MC Lars album has the same sound quality as the traffic report.

Check out this similar project from last year that adds RDS to a vintage radio.

Adding A Microphone Jack To A HAM Radio Handset

August 8, 2010 by 18 Comments

[dajjhman] wrote in to show us how he added a microphone jack to the handset of his Yaesu radio while retaining the DTMF functions. He states that there were some adapters available on the market, but they are non standard and didn’t really fit his needs. The modification itself is pretty simple, especially with his great documentation and clear pictures. For anyone else who might need this setup, this should be a great resource.

Hackaday Links: July 25, 2010

July 25, 2010 by 20 Comments

Radio Receiver

If you never got the chance to build one as a kid [JoOngle] takes you through the steps to build your own radio receiver. Details are a bit scarce but it’s nothing your friend Google can’t help you out with.

Fixing a Blackberry trackball

If your Blackberry trackball stops working well you can try this non-technical fix. Remember when mice used to have a ball in them and you would need to clean out the gunk from time to time? Forcefully skidding your Blackberry across a piece of paper does a similar service.

Linux time lapse

Open source can be a great help to small businesses. Here’s a way to use a Linux machine to make time-lapse movies from surveillance camera feeds. We especially enjoy the use of a desktop wallpaper that has the terminal commands necessary to start recording.

Host a webpage with Dropbox

Here’s a way to host a simple webpage using Dropbox. It’s one of those easy ideas that you wouldn’t come up with yourself. When you place an HTML file in your Dropbox you can get a public URL which will be built as a webpage when visited with a browser.

Inline splicing

To round out the weekend here’s [Osgeld’s] tips on inline wire splicing. We laughed as he recounted spearing himself with stray strands. This is pretty simple stuff but he’s explained it well and who’s to pass up a good tip?

Alternative Morse Code Keys

July 25, 2010 by 18 Comments

Add a bit of interest to your radio equipment with one of these unorthodox CW keys. [OH6DC] has been hard at work posting almost sixty of these hacks. Above you can see an alarm clock whose snooze button acts as the key, and a nail clipper used as a key. There’s a banana , a cross-country ski shoe , and a toaster key. The rest you’ll have to see for yourself. Any of these would work perfectly with that Morse code keyboard you’ve been wanting to build.

Terminal Node Controller In A Router

July 23, 2010 by 17 Comments

[Andrew] used a DSL router to make his own Terminal Node Controller. This will become part of an APRS-IS network, an Internet-based network built by amateur radio operators. The router used here is a Dlink DSL-502T with an AVR based TNC module attached to the serial port header. The phone line connector and its accompanying hardware have been removed to make room for the TNC module, which is supplied with 12V via that red wire. When the router boots up it sends data to the serial port header so the firmware on the TNC needed some tweaking to accommodate this (yay for open source).

Want some more APRS goodness? Check out this AVR APRS tracker.