Tagged: beacons

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 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.

sattv_beacon_3
sattv_beacon_4
eutelsat-21b-beacon-zoomed-in
signal-drifted-after-1-hour-passed
Loading image... Loading image... Loading image... Loading image...

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 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.

sattv_beacon_3
sattv_beacon_4
eutelsat-21b-beacon-zoomed-in
signal-drifted-after-1-hour-passed
Loading image... Loading image... Loading image... Loading image...

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.