Using SDR.HU to listen to AM radio sports

The Cubs won the pennant, and the Buckeyes lost to Penn State. I was able to listen to the radio calls of both of these through recievers connected to sdr.hu. The Cubs radio call was from WMVP-AM, ESPN Chicago 1000. I had some practice listening to them through the Farmington Hills, MI SDR run by KB8SPI. That system is a KiwiSDR with a PA0RDT Mini-Whip, and it tunes from 0-30 Mhz including all of the longwave (broadcast AM) band. »

Narrowband IoT (NB-IoT) as a low power cellular data protocol on the u-blox SARA-N2

In the process of looking at embedded radio components, I came across the u-blox SARA-N2, a low power device designed to provide low bandwidth cellular data coverage for Internet of Things devices - “low power consumption and extended coverage” being the operative buzzwords. Speeds are 227 Kbps down and 21 Kbps up, and it’s claimed to be “low power” though no specific power consumption figures are provided. It’s built on NB-IoT standards that are standardized in June 2016 by the 3GPP project and which are codified in their Release 13. »

sdr.hu and the emergence of lots of small wideband SDR receivers

sdr.hu is the home base for OpenWebRX, a remote spectrum monitoring system written by Andras HA7ILM. The system is designed to allow OpenWebRX servers, running on RTL-SDR or HackRF hardware, to share their radio spectrum and allow remote tuning of the available radio bandwidth. A typical installation will allow up to four remote listeners to independently tune in, and the tuning filters allow the listener to independently control the bandwidth of the receiver. »

full stack plane spotting and data analysis

The task at hand is simple. Whenever a particular airplane is visible overhead, send out a tweet with that notice. Don’t repeat yourself with this announcement more than twice an hour, but try not to have too much lag in reporting. The full stack of hardware and software to do this is not particularly complicated to use once you get it all running, but there are a series of issues and observations along the way that add to the complexity. »

Plane finding with dump1090

In March 2015 I wrote briefly about plane spotting with dump1090. In short, many airplanes have ADS-B transponders which squawk out their location, airspeed, and current conditions, and you can pick up those transmissions using an inexpensive RTL-SDR tuner stick and a simple antenna. I’ve been looking into this again to see if I can get a better understanding of how it works as well as to take advantage of a year plus of software development. »

Ann Arbor area APRS network status, January 2016

APRS is the “Automatic Position Reporting Service”, a system for sharing information about the position of participating amateur radio stations. Clients transmit position reports on 144.39 Mhz; digipeaters repeat these reports to other monitoring stations; and various IGate sites monitor transmissions and send their findings to aprs.fi which collects worldwide data. In recent memory there has been an APRS digipeater in Chelsea, Michigan with wide area coverage, good enough to pick up travellers on I-94 west of Ann Arbor. »

Dave New N8SBE to speak at ARROW on Software Defined Radio

Dave New N8SBE will be speaking at the January 2016 meeting of the ARROW radio club on the topic of Software Defined Radio. He will present an introduction to GNU Radio and the GNU Radio Companion visual programming environment, and the HackRF One Software Defined Transceiver from Great Scott Gadgets. The demo will include a disucssion of receiver and transmitter flow graphs, as well as resources to learn more about digital signal processing using the HackRF One and GNU Radio. »

Building a dipole antenna for your SDR tuner stick from an old set of headphones

Some notes before I try to do the build. The parts I have or know I can get: cheap earbud headphones, NooElec NESDR Mini 2 SDR tuner stick with whip antenna, Nokia 635 phone, antenna from an older NESDR Mini SDR tuner stick. Parts I need: a short adapter cable that provides antenna in for the SDR stick as a headphone jack socket. The SDR tuner comes with an antenna, but I want to replace it with a dipole - especially one cut to have a center point for FM broadcast on 88. »

plane spotting; some quick notes on a new software-defined radio setup

A couple of years ago, I got one of the first-generation RTL-SDR USB software defined radio units. These inexpensive devices are originally designed as TV tuners, but clever radio hackers figured out how to turn them into software-defined radios that tune to a broad spectrum of radio. After some experimental use I managed to cook the original unit which in its death throes no longer listened. The vendor (Nooelec) generously offered a modest discount on my next purchase, so I took them up on the 2d generation unit. »

Tune in to Skywarn nets in 50 states when severe weather threatens

This list of Skywarn nets is compiled from a list of Skywarn Twitter feeds and Broadcastify radio feeds. Networks are added when there is confirmed traffic. KE4KMD maintains a similar list, which was used in part to develop this one. There is a national Skywarn directory at Skywarn.org. This list is sorted by state, and from there grouped regionally by National Weather Service forecast office directory. In some cases, NWS forecast areas cross state boundaries, and those are noted. »

decoding radio digital modes without a radio, using WebSDR and fldigi

I’m interested in decoding radio digital modes without actually having a radio. The idea is that by using a web-based software defined radio (to tune in the signals) and the fldigi program (to decode the signals) that I should be able to “listen” to digital modes and start to explore the digital parts of the amateur and broadcast radio bands. I think I have all of the components, but I have yet to be able to get everything to work as expected. »

What the W8UM net looks like in software defined radio

A sample screen grab from tonight's W8UM net on 145.23. Please note that the radio I'm using looks like it's out of tune a little bit, since I'm actually listening here on 145.217. It was a good clear strong signal (the red/yellow line), even with the not very good antenna I have; it should be, since the transmitter is only about a mile from here. »