David writes: I’m developing an open source data mode using a FSK modem and powerful LDPC codes. The initial use case is the Open IP over UHF/VHF project, but it’s available in the FreeDV API as a general purpose mode for sending data over radio channels. Via Rowetel.
Tag Archives: radio
M17 open source radio
Wojciech Kaczmarski (SP5WWP) and his team have been working on the M17 open source digital radio project: Open source handheld for a novel digital communication standard called M17. The goal here is to kick the proprietary protocols off the airwaves. To do that, it’s not just good enough to be open, it has to be […]
DC40 receiver
Michael LeBlanc has a nice write-up on building a direct conversion radio receiver: In the late winter of 2018-19, I decided to build a receiver that would provide a performance improvement to the regen I built a couple of years ago. I wanted the radio to receive AM and SSB signals between 160m and 20m […]
DIY Arduino FM radio
Nick over at educ8s.tv shared detailed instructions of how to build this DIY Art Deco style FM Radio project using Arduino: Let’s see what we are going to build today! As you can see, we are going to build an Art Deco style FM radio receiver. The design of this radio is based on this […]
Two transistor superheterodyne shortwave receiver
Dilshan Jayakody writes: This is two transistor and two IF transformer based superheterodyne receiver which is designed to receive 13m to 41m bands. With quiet good external antenna this receiver performs similar to commercially available shortwave receiver and its audio quality is in very satisfactory level. This receiver can be constructing on PCB, breadboard or […]
VHF Aircraft radio communications receiver
Dilshan Jayakody published a new build, a VHF Aircraft radio communications receiver: This is simple radio receiver project which is capable to receive aviation radio voice signals which are transmit between 118MHz to 138MHz in AM (A3E). We got initial idea of this project by reading Sverre Holm’s (LA3ZA) article about “cheap VHF receiver project”. Like […]
FBI radio teardown – Motorola Spectra
KF5OBS did a teardown of a former FBI radio a Motorola Spectra: Tearing down a former FBI Radio, a 110 Watt FM / APCO25 (P25) VHF Motorola Spectra T99DX with DES hardware encryption module.
RadioduinoWRT – a do it yourself webradio
Raffael Herrmann wrote in to let us know about his latest project the RadioduinoWRT – a do it yourself webradio: In the last weeks I built a webradio by myself. It made from an Arduino, an hacked TP-Link WR703N router and some interface parts. It’s fitted into a beautiful Yamaha enclosing and supports the original Yamaha interface, […]
Bus Pirate script to recover bricked radio
Koolatron over at the Bitcraze forum re-program the Crazyradio over SPI using the BusPirate and this script, available at github: I’ve knocked together a perl script to reflash a busted crazyradio over SPI using a Bus Pirate. This saved me from a firmware upgrade gone bad. Get an assembled Bus Pirate for $30, including world-wide shipping. Also available from our […]
Futaba 10C radio hacked to accept a Spektrum DSM module
Futaba 10C radio hacked to accept a Spektrum DSM module: Tom from Damage Designs has Hacked his Futaba 10C Radio to accept a Spektrum DSM Module. Turns out these were not designed to function together but with a bit of effort Tom got them to work just fine. The actual protocol seems to be the […]
iPod FM transmiter
Electronics-DIY has instructions on how to build a simple portable FM transmitter that would allow your iPod to broadcast music over radio waves. It is simple to build and fits into a mouse case. It works quite easy, there is a power switch on the bottom to turn it on and tune your radio and […]
7400 competition entry: AM radio
Jason entered his AM radio into the Open 7400 Logic Competition: One unusual use for a logic chip is as an analog amplifier. Most logic with inverting outputs can be used this way. In order to demonstrate this functionality, I’ve built an AM radio with a 74HCU04 inverter. The inverters are used both as RF […]
App note: Intro to digital communications systems
Digital modulation techniques are seeing increasing use worldwide. In the US, the FCC is actually mandating narrowband digital mobile radio (DMR) for certain Land Mobile Radio (LMR) users as explained in this Digital Mobile Radio Association white paper. Datasheets for various chips increasingly made reference to acronyms like GMSK, FSK and others. Agilent has published […]
Barcode challenge for radio operators
Clearing out old posts before the new year, some of these might seem ancient. How to hand decode a QR code transmitted over HAM radio slow scan TV. Via Hack a Day. http://www.swharden.com/blog/2010-11-11-deciphering-qr-code-from-radio-spectrograph/
Marine AIS data transmissions
If you live near naviagable waterways, you may want to tune your FM monitor receiver to 161.975 MHz and 162.025 MHz FM. If you hear data bursts, you are able to receive ships sending messages using the Automatic Identification System (AIS). These data transmissions are sent using GMSK modulation, and can be decoded for readout […]
Peer to peer control network uses TV spectrum white space
New patent application #20100309806 describes a peer to peer radio system designed to utilize the “white space” between TV channels. The system receives data from RF and geolocation sensors and processes them along with information from the FCC’s white space database to assign operating frequencies on a dynamic basis.