m0xpd writes: I’ve been playing with a new RF generator for the IoT beacon… Actually, I do myself a disservice, because I’ve done rather more than just play with the RF generator. First, I’ve replaced the little USB to serial dongle which I used to program the original system and built a complete interface, using the […]
Category Archives: RF
Georges F6DFZ’s very stylish homebrew version of the Scout Regen receiver
Dave Richards AA7EE has published an article about Georges F6DFZ’s homebrew regen receiver: Several months ago, Georges F6DFZ sent me pictures of a Manhattan project he had just completed, using Rex’s MeSQUARES, and I have waited far too long to share it with you. It began life as a copy of the Ten Tec 1253 regen, but […]
LDMOS amplifiers
Pete (N6QW) writes: This project encompasses proving an Arduino Control of a hi Power Linear Amplifier. It is a new departure for N6QW as it has extensive I/O requirements which required moving to the Mega 2560 a Arduino variant that has 56 Digital I/O and 16 Analog Inputs. The on board memory is 256K The […]
Tracker for thing, APRS tracker with DRA818V
Tony G from Weird-Lab writes, “The idea of this project was to build a trackuino board with small gps module, low power arduino pro mini (3.3v @8mhz), a VHF transceiver DRA818V, and power management integrated.” Project info at Weird-Lab site.
Crystal motional parameters
Craig writes: Ever tried searching through your datasheets for the motional parameters of that quartz crystal you just bought? Good luck! Vendors simply don’t specify these parameters to general end users, and for most applications that’s OK. But for high Q oscillator and filter design, measuring and matching crystals can be important. This video discusses […]
Simple crystal tester
Dilshan Jayakody writes: This is simple Colpitts oscillator to test commonly available passive crystals which range between 2MHz to 27MHz. This unit must connect to an oscilloscope and/or frequency counter to get the frequency of the crystal. This circuit is design to work around 9V to 12V DC power source. Both 2SC930 transistors can replace […]
Building a better RTL-SDR TCXO
Craig posted an article describing how he built a 28.8MHz RTL-SDR TCXO, that is available on github: Here’s a scratch-built 28.8MHz TCXO capable of +-1ppm stability from 0C-55C; best of all, it’s not only easy to build, but is designed entirely from readily available and inexpensive components. For improved temperature stability, the main oscillator can […]
14 GHz Ku Band Block UpConverter
Sebastian (a.k.a KF5OBS) writes, “A quick look at what it takes to make a Block UpConverter (BUC) for the 14 GHz Ku-Band satellite uplink band work. A BUC is used in professional Broadcast TV environments to convert a video signal from a L-Band intermediate frequency to the 14 GHz range to be received by broadcast […]
The Sproutie “SPT” Beacon – A legal, unlicensed HiFER beacon
Dave Richards (a.k.a. AA7EE) has written an article detailing his “SPT” Sproutie HiFer beacon project: My first “proof of concept” at putting together a beacon for this band was to connect an N0XAS PicoKeyer in beacon mode to my Pixie 2 transmitter. With the PiicoKeyer, if you insert the prosign BN at the end of stored […]
TI Design Contest: Envision the ultimate NFC wearable
TI has announced a contest for NFC based wearable designs. Do you dream of creating a solution to make monitoring health and fitness activities easier? Using near field communication (NFC) in your designs can help! We want to hear your ideas for the next wearable design based on our RF430FRL15xH NFC sensor transponder in our […]
Sniffing Crazyflie’s radio with HackRF blue
arnaud acquired a HackRF Blue and has been busy coding up a GNURadio project for analyzing Crazyflie radio transmissions. Crazyflie is a nano quadcopter/drone controlled over a wireless link. The Crazyradio is the official radio dongle for the Crazyflie Nano Quadcopter. It is a 2.4GHz USB radio dongle based on the nRF24LU1+ chip from Nordic […]
YOUSDR remote RTL-SDR software
Sixuniform has released YOUSDR v0.1 Alpha, an RTL-SDR webinterface for Raspian / Raspberry Pi. This is a web-wrapper for the rtl-sdr softwares. Currently it commands rtl_fm, rtl_tcp and dump1090. The software can be downloaded from its GitHub. The instructions on the GitHub page show how to set it up on a Raspberry Pi running Raspbian, […]
Arduino compatible LightBlue Bean adds Node-RED support
Tektronix RSA 306 – GPS receiver and clock reference
KF5OBS writes, “The Tektronix RSA 306 is a great low-cost USB 3.0 spectrum analyzer for up to 6 GHz in an ultra low-profile format. If paired with the RSA Map function of SignalVu-PC and a GPS receiver, it becomes an extremely powerful tool for interference hunting and signal strength mapping. This article shows a possible way […]
OpenSprinkler Firmware 2.1.1 new feature: Control remote power sockets
We previously covered Ray’s OpenSprinkler. Now it has added a new feature to remotely toggle radio frequency power sockets: This allows OpenSprinkler to not only switch sprinkler valves, but also easily control powerline devices such as lights, heaters, pumps, fans. Looking for a programmable way to control Christmas lights? Look no further! This feature is […]
Reverse engineering a Verisure wireless alarm
Here’s an informative two-part series of posts over at FunOverIP detailing how to reverse engineer a Verisure wireless alarm. Part 1 details the beginning steps such as finding the modules radio frequency and modulation type, analyzing the chipset datasheet and using GNU Radio.
Viewing a VHS tape using RTL-SDR and TV Sharp software
Here’s a different and unconventional way to view a VHS tape (as if VHS tapes aren’t considered unusual enough today). DogsRNiceMineCraft posted this video on YouTube showing video received using an RTL-SDR dongle. I got a VCR today and wanted to see if I could receive the signal from the RF out using TV sharp. […]
Introducing RFToy, an Arduino-compatible gadget for radio frequency modules
Ray Wang from RaysHobby has informed us of his latest open-source project called RFToy: it’s an Arduino-compatible microcontroller board for interfacing with radio frequency (RF) modules, such as the popular 433/315MHz transmitter/receiver, and the nRF24L01 transceiver. The RFToy has a built-in ATmega328, USB-serial converter (CH340G), 128×64 OLED display, three buttons, and a coin battery holder. Programming […]
Video: FlexRadio open API
During the TAPR/ARRL Digital Communications Conference in Austin last September, Stephen Hicks N5AC gave this presentation on interfacing with FlexRadio using their open API. Part II of this presentation was given by Graham Haddock KE9H, and discussed the FlexRadio wavefrom API. It is available from HamRadioNow. FlexRadio produces a series of high-end SDR’s, with the […]
Project: extracting and geographically plotting DTRS site information
Lui Gough has been researching the Australian railroad system’s new digital radio system and has posted detailed observations: As a radio enthusiast, and highly observant public transport user, I’ve made many notes about the deployment of the new Digital Train Radio System (DTRS) sites. This new system is based upon GSM-R in the 1800Mhz band, […]