Tagged: beacons

SDRAngel Features Overview: ADS-B, APT, DVB-S, DAB+, AIS, VOR, APRS, and many more built-in apps

SDRAngel is a general purpose software defined radio program that is compatible with most SDRs including the RTL-SDR. We've posted about it several times before on the blog, however we did not realize how much progress has occurred with developing various built in plugins and decoders for it.

Thanks to Jon for writing in and sharing with us a demonstration video that the SDRAngel team have released on their YouTube channel. From the video we can see that SDRAngel now comes stock with a whole host of built in decoders and apps for various radio applications making it close to an all-in-one SDR platform. The built in applications include:

  • ADS-B Decoder: Decodes aircraft ADS-B data and plots aircraft positions on a map
  • NOAA APT Decoder: Decodes NOAA weather satellite images (in black and white only)
  • DVB-S: Decodes and plays Digital TV DVB-S and DVB-S2 video
  • AIS: Decodes marine AIS data and plots vessel positions on a map
  • VOR: Decodes VOR aircraft navigational beacons, and plots bearing lines on a map, allowing you to determine your receivers position.
  • DAB+: Decodes and plays DAB digital audio signals
  • Radio Astronomy Hydrogen Line: With an appropriate radio telescope connected to the SDR, integrates and displays the Hydrogen Line FFT with various settings, and a map of the galaxy showing where your dish is pointing. Can also control a dish rotator.
  • Radio Astronomy Solar Observations: Similar to the Hydrogen line app, allows you to make solar measurements.
  • Broadcast FM: Decoding and playback. Includes RDS decoding.
  • Noise Figure Measurements: Together with a noise source you can measure the noise figure of a SDR.
  • Airband Voice: Receive multiple Airband channels simultaneously
  • Graves Radar Tracker: For Europeans, track a satellite and watch for reflections in the spectrum from the French Graves space radar. 
  • Radio Clocks: Receive and decode accurate time from radio clocks such as MSF, DCF77, TDF and WWVB.
  • APRS: Decode APRS data, and plot APRS locations and moving APRS enabled vehicles on a map with speed plot.
  • Pagers: Decode POCSAG pagers
  • APRS/AX.25 Satellite: Decode APRS messages from the ISS and NO-84 satellites, via the built in decoder and satellite tracker.
  • Channel Analyzer: Analyze signals in the frequency and time domains
  • QSO Digital and Analog Voice: Decode digital and analog voice. Digital voice handled by the built in DSD demodulator, and includes DMR, dPMR and D-Star.
  • Beacons: Monitor propagation via amateur radio beacons, and plot them on a map.

We note that the video doesn't show the following additional features such as an analog TV decoder, the SDRAngel "ChirpChat" text mode, a FreeDV decoder and several other features.

Using an Airspy HF+ Discovery to Hunt for HF Beacons

Over on YouTube Tech Minds has posted a video of him using an Airspy HF+ Discovery to hunt for signals like non-direction beacons (NDB's) and other morse code CW beacons. The Airspy HF+ Discovery is a new software defined radio that builds upon the already excellent original Airspy HF+.

One key improvement that many people have been experimenting with is it's improved VLF and LF capabilities, which is where most beacons are. It is capable of tuning down to 0.5 kHz (500 Hz). Over on Twitter, @prog (creator of these Airspy products) has been experimenting with simple and small ferrite loop antennas for VLF/LF and finding excellent results due to the low noise figure and good impedance matching of the HF+ Discovery.

Hunting LF/MF/HF Beacons With An Airspy HF+ Discovery

Receiving Satellite TV Beacons with an RTL-SDR and LNB

Thank you to an anonymous contributor for sharing his experiences with trying to receive satellite TV beacons with his RTL-SDR. Satellite TV is typically up at 10.7 to 11.7 GHz which is far too high for an RTL-SDR to receive. So to receive these frequencies with the RTL-SDR he uses a satellite TV LNB (an LNB is essentially a downconverter and satellite dish feed), a DIY Bias T and a 90 cm dish. He writes:

Almost all television satellites have a special frequency for transmitting a beacon signal. The beacon signal is a reference signal with fixed frequency, power and [maybe] without modulation that is sent usually by satellites. One of the most important techniques used for satellite wave propagation studies is satellite beacon signal measurement. (http://eej.aut.ac.ir/article_433.html)

I used an universal LNB, DIY bias-T and a fixed 90cm dish pointed at 26 degrees East. By connecting 18 volts DC to LNB I am able to activate the 9750 Mhz local oscillator and horizontal operating mode of LNB.

Means that anything received with LNB between 10.7-11.7 GHz can be easily seen in 950-1950 MHz range, using RTL-SDR.

I used this set-up to receive the GEO satellites beacons. A list of beacon frequencies" http://frequencyplansatellites.altervista.org/Beacon-Telemetry_Europe-Africa-MiddleEast.html.

It is useful for measuring attenuation caused by heavy rain in Ku band or accurate dish positioning or even measuring frequency drift in LNB local oscillator caused by wind and temp change during a timespan.

It seems that the right signal is Eutelsat 21B and left Es'hail 1.

In picture 4 signal captured immediately after turning on LNB. but all others are captured after at least 5 hours of warming up.

MAYBE oscillator needs a stabilize time or temp change may caused the drift.

If you are interested in receiving these beacons, Daniel Estevez has also performed similar experiments with his RTL-SDR and an LNB as well, and has written about it on his blog.

Below we show some images of beacons shown in SDR# that the anonymous contributor received with his setup.

SDRAngel Features Overview: ADS-B, APT, DVB-S, DAB+, AIS, VOR, APRS, and many more built-in apps

SDRAngel is a general purpose software defined radio program that is compatible with most SDRs including the RTL-SDR. We've posted about it several times before on the blog, however we did not realize how much progress has occurred with developing various built in plugins and decoders for it.

Thanks to Jon for writing in and sharing with us a demonstration video that the SDRAngel team have released on their YouTube channel. From the video we can see that SDRAngel now comes stock with a whole host of built in decoders and apps for various radio applications making it close to an all-in-one SDR platform. The built in applications include:

  • ADS-B Decoder: Decodes aircraft ADS-B data and plots aircraft positions on a map
  • NOAA APT Decoder: Decodes NOAA weather satellite images (in black and white only)
  • DVB-S: Decodes and plays Digital TV DVB-S and DVB-S2 video
  • AIS: Decodes marine AIS data and plots vessel positions on a map
  • VOR: Decodes VOR aircraft navigational beacons, and plots bearing lines on a map, allowing you to determine your receivers position.
  • DAB+: Decodes and plays DAB digital audio signals
  • Radio Astronomy Hydrogen Line: With an appropriate radio telescope connected to the SDR, integrates and displays the Hydrogen Line FFT with various settings, and a map of the galaxy showing where your dish is pointing. Can also control a dish rotator.
  • Radio Astronomy Solar Observations: Similar to the Hydrogen line app, allows you to make solar measurements.
  • Broadcast FM: Decoding and playback. Includes RDS decoding.
  • Noise Figure Measurements: Together with a noise source you can measure the noise figure of a SDR.
  • Airband Voice: Receive multiple Airband channels simultaneously
  • Graves Radar Tracker: For Europeans, track a satellite and watch for reflections in the spectrum from the French Graves space radar. 
  • Radio Clocks: Receive and decode accurate time from radio clocks such as MSF, DCF77, TDF and WWVB.
  • APRS: Decode APRS data, and plot APRS locations and moving APRS enabled vehicles on a map with speed plot.
  • Pagers: Decode POCSAG pagers
  • APRS/AX.25 Satellite: Decode APRS messages from the ISS and NO-84 satellites, via the built in decoder and satellite tracker.
  • Channel Analyzer: Analyze signals in the frequency and time domains
  • QSO Digital and Analog Voice: Decode digital and analog voice. Digital voice handled by the built in DSD demodulator, and includes DMR, dPMR and D-Star.
  • Beacons: Monitor propagation via amateur radio beacons, and plot them on a map.

We note that the video doesn't show the following additional features such as an analog TV decoder, the SDRAngel "ChirpChat" text mode, a FreeDV decoder and several other features.

Using an Airspy HF+ Discovery to Hunt for HF Beacons

Over on YouTube Tech Minds has posted a video of him using an Airspy HF+ Discovery to hunt for signals like non-direction beacons (NDB's) and other morse code CW beacons. The Airspy HF+ Discovery is a new software defined radio that builds upon the already excellent original Airspy HF+.

One key improvement that many people have been experimenting with is it's improved VLF and LF capabilities, which is where most beacons are. It is capable of tuning down to 0.5 kHz (500 Hz). Over on Twitter, @prog (creator of these Airspy products) has been experimenting with simple and small ferrite loop antennas for VLF/LF and finding excellent results due to the low noise figure and good impedance matching of the HF+ Discovery.

Hunting LF/MF/HF Beacons With An Airspy HF+ Discovery

Receiving Satellite TV Beacons with an RTL-SDR and LNB

Thank you to an anonymous contributor for sharing his experiences with trying to receive satellite TV beacons with his RTL-SDR. Satellite TV is typically up at 10.7 to 11.7 GHz which is far too high for an RTL-SDR to receive. So to receive these frequencies with the RTL-SDR he uses a satellite TV LNB (an LNB is essentially a downconverter and satellite dish feed), a DIY Bias T and a 90 cm dish. He writes:

Almost all television satellites have a special frequency for transmitting a beacon signal. The beacon signal is a reference signal with fixed frequency, power and [maybe] without modulation that is sent usually by satellites. One of the most important techniques used for satellite wave propagation studies is satellite beacon signal measurement. (http://eej.aut.ac.ir/article_433.html)

I used an universal LNB, DIY bias-T and a fixed 90cm dish pointed at 26 degrees East. By connecting 18 volts DC to LNB I am able to activate the 9750 Mhz local oscillator and horizontal operating mode of LNB.

Means that anything received with LNB between 10.7-11.7 GHz can be easily seen in 950-1950 MHz range, using RTL-SDR.

I used this set-up to receive the GEO satellites beacons. A list of beacon frequencies" http://frequencyplansatellites.altervista.org/Beacon-Telemetry_Europe-Africa-MiddleEast.html.

It is useful for measuring attenuation caused by heavy rain in Ku band or accurate dish positioning or even measuring frequency drift in LNB local oscillator caused by wind and temp change during a timespan.

It seems that the right signal is Eutelsat 21B and left Es'hail 1.

In picture 4 signal captured immediately after turning on LNB. but all others are captured after at least 5 hours of warming up.

MAYBE oscillator needs a stabilize time or temp change may caused the drift.

If you are interested in receiving these beacons, Daniel Estevez has also performed similar experiments with his RTL-SDR and an LNB as well, and has written about it on his blog.

Below we show some images of beacons shown in SDR# that the anonymous contributor received with his setup.

A Homemade PCB Log-Periodic Antenna

Ham radio enthusiast and RF designer Marco Cardelli (IZ5IOW) recently wrote in and wanted to share his PCB log periodic antenna design which he has been using together with RTL-SDR dongles. Log periodic’s are very wideband directional antennas that can easily be printed onto a circuit board.

Marco’s antenna covers a frequency range of 900 MHz – 2600 MHz.  The original principal focus was for EMI/EMC measurements, but Marco writes that it works perfectly fine for microwave experiments on the 23 and 13cm bands of wi-fi links. Marco currently uses this antenna for reception of microwave beacons. Currently there are no designs or plans on his website for the antenna, but we suspect that he will put them up soon.

If you’d rather purchase an antenna like this instead building one, then we’ve seen in the past good reviews from the PCB antennas available from wa5vjb at www.wa5vjb.com.

The wideband PCB log-periodic antenna.
The wideband PCB log-periodic antenna.
Return Loss of the PCB Log Periodic antenna.
Return Loss of the PCB Log Periodic antenna.