Tagged: rtl-sdr

Android App Aerial TV Banned from Google Play – Now Available on Amazon

Aerial TV is an Android app that allows you to watch DVB-T TV with an RTL-SDR on a mobile device. We posted about Aerial TV back in April and it was available on the Google Play store back then. Unfortunately Aerial TV has recently been banned from the Google Play store as apparently the app can be used to display copyrighted material from TV. The author writes the following on a Facebook post:

Google Play has suspended Aerial TV due to “[Aerial TV] claims to provide copyrighted contents from TV channels”. According to Google apps that display live TV are of “questionable nature”. I am trying to clarify what they mean. I would like to apologize to all affected users. If you have any concerns, feel free to get in touch with Google directly.

This is quite odd and probably a mistake. But if you are looking for Aerial TV it is now available on the Amazon app store with a current 35% discount. If you bought the app on the Google Play store then to get new updates you will need to uninstall it, contact the developer for a refund, and then purchase it again on the Amazon store. More info about that is available on the Facebook page. Updates about it’s availability will always be provided on the official website at aerialtv.eu.

Asking an Amazon Echo to Spot Planes with help from an RTL-SDR and Raspberry Pi

Amazon Echo is a smart home device which is essentially a hands free speaker that responds to voice commands in a similar way to ‘Okay Google’ and Siri does on your phone. With voice commands you can ask it to do things like play music, make a call or send a message, answer any question, control smart home devices like fans and locks and order items from Amazon.

Over on his blog Nick Sypteras has written about teaching his Amazon Echo a new ‘skill’ which allows it to automatically detect and read out what aircraft is flying outside his window, and where it is going. A skill is basically a plugin that you can code up to give your Amazon Echo new voice command functions and behavior.

The Echo skill gathers the live local ADS-B plane data via dump1090’s json output which runs on a networked Raspberry Pi with RTL-SDR dongle attached. The data is loaded into a database, which is then queried for the closest plane to the Echo’s location. Finally the program scrapes the closest flights departure and arrival data from FlightRadar24 before speaking it through the Echo’s speaker. Nicks code is freely available over on his GitHub page.

This project reminds us of a previous post where we posted about Simon Aubury’s work in creating a Raspberry Pi and RTL-SDR based aircraft camera tracking system. Simon’s system used live ADS-B data to point a camera directly at aircraft as they passed over his house.

It also reminded us of this British Airways video billboard that was popular a few years ago. The ad featured a young boy who would point directly at passing aircraft with text displaying the flight information. They used a commercial networked ADS-B device to gather live ADS-B data (internet based ADS-B data from sites like flightradar24.com has a time lag, so it is not suitable for time sensitive applications like this), and whenever a passing British Airways aircraft was detected the ad would play.

Video Tutorials: Setting up an RTL-SDR and HackRF with SDR-Console V3, Using the HackRF to find your Cellphone Signal and more

Over on his YouTube channel user Corrosive has uploaded a set of videos that show how to install and get started with an RTL-SDR or HackRF with SDR-Console V3.  The video series starts from the very beginning with installing the drivers via zadig, and then goes on to show how to download, install and use SDR-Console V3.

In one of his later videos Corrosive also shows how to optimally configure the settings in SDR-Console V3 and SDR# for optimal reception and viewing.

In a newer video he also shows how he uses the HackRF as a spectrum analyzer to find his cellphone signal. Regarding this video, Corrosive wrote in to us and said the following:

For a while now I’ve been trying to find the frequency of my cell phone, looking frequencies up online and trying to find an app that would tell me my current frequency. None of these things seem to work and scanning the band manually I always came up dry because I wasn’t 100% sure where I needed to look.

Further videos on his channel also show how to receive ADSB data with an RTL-SDR and Android phone, and how he repurposed a rabbit ears antenna into a V-dipole antenna for receiving Satcom pirates.

Corrosive has done a good job putting out SDR and radio related videos over the past couple of weeks so it may be a channel to subscribe to if you are interested in this type of content.

Using National Weather Service Stations for Forward Scatter Meteor Detection

Over on his blog Dave Venne has been documenting his attempts at using National Weather Service (NWS) broadcasts for forward scatter meteor detection with an RTL-SDR. Forward scatter meteor detection is a passive method for detecting meteors as they enter the atmosphere. When a meteor enters the atmosphere it leaves behind a trail of highly RF reflective ionized air. This ionized air can reflect far away signals from strong transmitters directly into your receiving antenna, thus detecting a meteor.

Typically signals from analog TV and broadcast FM stations are preferred as they are near the optimal frequency for reflection of the ionized trails. However, Dave lives in an area where the broadcast FM spectrum is completely saturated with signals, leaving no empty frequencies to detect meteors. Instead Dave decided to try and use NWS signals at 160 MHz. In the USA there are seven frequencies for NWS and they are physically spaced out so that normally only one transmitter can be heard. Thus tuning to a far away station should produce nothing but static unless a meteor is reflecting its signal. Dave however does note that the 160 MHz frequency is less than optimal for detection and you can expect about 14 dB less reflected signal from meteors.

So far Dave has been able to detect several ‘blips’ with his cross-dipole antenna, RTL-SDR and SDR#. He also uses the Chronolapse freeware software to perform timelapse screenshots of the SDR# waterfall, so that the waterfall can be reviewed later. Unfortunately, most of the blips appear to have been aircraft as they seem to coincide with local air activity, and exhibit a Doppler shift characteristic that is typical of aircraft. He notes that the idea may still work for others who do not live near an airport.

A possible meteor detection in SDR#.
A possible meteor detection in SDR#.
Aircraft detection doppler
Aircraft detection doppler

We note that if you are interested in detecting aircraft via passive forward scatter and their Doppler patterns, then this previous post on just that may interest you.

Talking to Ghosts with an RTL-SDR Dongle

Back in November of last year we posted about Doug Haber’s gqrx-ghostbox which is software that turns your RTL-SDR into an electronic voice phenomenon (EVP) tool, or in other words a ‘ghost box’ or ‘spirit box’. A ghost box is essentially a device that rapidly tunes between broadcast radio stations, creating mismashed audio of multiple stations. Paranormal researchers believe that such a tool can be used to communicate with ghosts or spirits. Over on Amazon commercial ghost boxes/spirit boxes seem to retail for anywhere from $70 USD to $140 USD so an RTL-SDR can be a budget way to get into paranormal research.

Over on her blog paranormal investigator shielaaliens has uploaded a post and video demonstrating an RTL-SDR based ghost box in action. Sheila actually doesn’t use the grqx-ghostbox software, but instead she just uses SDR# with a frequency scanner plugin set to rapidly scan through the broadcast band. In the video she asks the SDR# ghost box a few control questions such as “can you say kitty cat” and “can you say Nantucket”. In response the SDR# ghost box appears to respond with those exact words. Her Facebook post with the video can be found here.

Of course this might all sound pretty far fetched for most readers of this blog, but it is an application that the RTL-SDR is now being used for nonetheless!

SDR-Console V3 Latest Update: Signal History & Receiver Panes

SDR-Console is a popular RTL-SDR compatible multi purpose SDR software package which is similar to programs like SDR#, HDSDR and SDRuno. Currently SDR-Console V2 is the stable version and SDR-Console V3 is in a beta state. A few days ago SDR-Console V3 Preview 6 was released. It comes with some very interesting new features including a built in Airspy server, a recording scheduler, a new feature called signal history and a new receivers pane.

Over on his blog Nils Schiffhauer (DK8OK) has been reviewing the new release of SDR-Conosle V3 and writes the following information about some of the new features:

  • “Signal History” takes the signal strength of the given bandwidth each 50 milliseconds, which can be saved in a CSV file. It is also shown in three different speeds on a display.
  • “Receivers’ Pane” shows up to six combos of spectrum/spectrogram of the complete up to 24 parallel demodulators (they additionally can be shown in the Matrix, as in former versions).

“Signal History” offers many applications, to name just three:

  • analyze fading and its structure with an unsurpassed time resolution of 50 ms
  • document fade-in and fade out
  • measure signal-to-noise ratio of signals

In addition Nils has also uploaded a very useful 19 page PDF where he writes step by step instructions and shows numerous examples of the new signal history tool.

DK8OK's SDR-Console V3 P6 Screenshot. Showing multiple receiver panes and the new signal history feature.
DK8OK’s SDR-Console V3 P6 Screenshot. Showing multiple receiver panes and the new signal history feature.
DK8OK's screenshot of the signal history toolbox.
DK8OK’s screenshot of the signal history toolbox.

Testing the Outernet Dreamcatcher: Linux Based ARM PC with Built in RTL-SDR

Last week we posted about Outernet’s new Dreamcatcher unit which is an RTL-SDR + L-band LNA + computing board all on the same PCB. The Dreamcatcher comes with a new active ceramic L-band patch antenna, costs $99 USD (plus shipping) and can be bought directly from their store. Outernet were kind enough to send us a review unit, and we’ve been testing it for the past few weeks. This post is a review of the unit.

Background

Outernet is a free data service that uses L-band satellites to beam down information like news, weather updates, Wikipedia articles, books and more.

In the past Outernet have used the $9 USD C.H.I.P computing board, an RTL-SDR dongle and an external LNA as the receiving hardware for their data service. However, popularity of the Outernet service has been severely hindered by the huge supply shortages of the C.H.I.P. Over the past year or so it has been almost impossible to get a hold of a C.H.I.P unit if you did not back the Kickstarter or buy one from Outernet’s first initial stock. By manufacturing their own PCB including the computing hardware, Outernet must be hoping to be able to control their stock situation, and not rely on third parties who may not be able to deliver.

At the moment the Dreamcatcher can only be run on their new Armbian image. The older Skylark image has been removed from their servers presumably because the Outernet signal is going to change in the near future and the old demodulator on Skylark may no longer work. The Armbian image is basically just standard Armbian and at the moment does not actually run any Outernet software, and cannot decode their signal, but this is being worked on. Eventually they hope to replace Skylark with a standard decoding app that runs on Armbian.

In this post we’ll review the Dreamcatcher with Armbian and consider it as a general purpose receiver (not just for Outernet), and we’ll also review the new active ceramic patch antenna as well.

Dreamcatcher Overview

The Dreamcatcher is a single PCB that combines an RTL-SDR, Linux (Armbian) based computing hardware, and an L-band LNA and filter. 

On first impressions we noticed that the PCB is relatively large square at about 12 cm by 12 cm. The most prominent chip is the Allwinner A13 SoC. The RTL-SDR circuitry is positioned in the upper right with the RF sections (R820T and LNA) both covered with RF shielding cans. There is no onboard WiFi circuitry, but a small ‘EDUP’ branded WiFi dongle is included and plugs into one of the USB ports on the PCB.

We measured the Dreamcatcher to be using about 400 mA – 600 mA while idle and 800 mA while utilizing the RTL-SDR and 100% CPU. Heat is not an issue as the Dreamcatcher stays relatively cool during its operation even at 100% CPU with the CPU only getting up to about 45 degrees C.

Continue reading

Android App Aerial TV Banned from Google Play – Now Available on Amazon

Aerial TV is an Android app that allows you to watch DVB-T TV with an RTL-SDR on a mobile device. We posted about Aerial TV back in April and it was available on the Google Play store back then. Unfortunately Aerial TV has recently been banned from the Google Play store as apparently the app can be used to display copyrighted material from TV. The author writes the following on a Facebook post:

Google Play has suspended Aerial TV due to “[Aerial TV] claims to provide copyrighted contents from TV channels”. According to Google apps that display live TV are of “questionable nature”. I am trying to clarify what they mean. I would like to apologize to all affected users. If you have any concerns, feel free to get in touch with Google directly.

This is quite odd and probably a mistake. But if you are looking for Aerial TV it is now available on the Amazon app store with a current 35% discount. If you bought the app on the Google Play store then to get new updates you will need to uninstall it, contact the developer for a refund, and then purchase it again on the Amazon store. More info about that is available on the Facebook page. Updates about it’s availability will always be provided on the official website at aerialtv.eu.

Asking an Amazon Echo to Spot Planes with help from an RTL-SDR and Raspberry Pi

Amazon Echo is a smart home device which is essentially a hands free speaker that responds to voice commands in a similar way to ‘Okay Google’ and Siri does on your phone. With voice commands you can ask it to do things like play music, make a call or send a message, answer any question, control smart home devices like fans and locks and order items from Amazon.

Over on his blog Nick Sypteras has written about teaching his Amazon Echo a new ‘skill’ which allows it to automatically detect and read out what aircraft is flying outside his window, and where it is going. A skill is basically a plugin that you can code up to give your Amazon Echo new voice command functions and behavior.

The Echo skill gathers the live local ADS-B plane data via dump1090’s json output which runs on a networked Raspberry Pi with RTL-SDR dongle attached. The data is loaded into a database, which is then queried for the closest plane to the Echo’s location. Finally the program scrapes the closest flights departure and arrival data from FlightRadar24 before speaking it through the Echo’s speaker. Nicks code is freely available over on his GitHub page.

This project reminds us of a previous post where we posted about Simon Aubury’s work in creating a Raspberry Pi and RTL-SDR based aircraft camera tracking system. Simon’s system used live ADS-B data to point a camera directly at aircraft as they passed over his house.

It also reminded us of this British Airways video billboard that was popular a few years ago. The ad featured a young boy who would point directly at passing aircraft with text displaying the flight information. They used a commercial networked ADS-B device to gather live ADS-B data (internet based ADS-B data from sites like flightradar24.com has a time lag, so it is not suitable for time sensitive applications like this), and whenever a passing British Airways aircraft was detected the ad would play.

Video Tutorials: Setting up an RTL-SDR and HackRF with SDR-Console V3, Using the HackRF to find your Cellphone Signal and more

Over on his YouTube channel user Corrosive has uploaded a set of videos that show how to install and get started with an RTL-SDR or HackRF with SDR-Console V3.  The video series starts from the very beginning with installing the drivers via zadig, and then goes on to show how to download, install and use SDR-Console V3.

In one of his later videos Corrosive also shows how to optimally configure the settings in SDR-Console V3 and SDR# for optimal reception and viewing.

In a newer video he also shows how he uses the HackRF as a spectrum analyzer to find his cellphone signal. Regarding this video, Corrosive wrote in to us and said the following:

For a while now I’ve been trying to find the frequency of my cell phone, looking frequencies up online and trying to find an app that would tell me my current frequency. None of these things seem to work and scanning the band manually I always came up dry because I wasn’t 100% sure where I needed to look.

Further videos on his channel also show how to receive ADSB data with an RTL-SDR and Android phone, and how he repurposed a rabbit ears antenna into a V-dipole antenna for receiving Satcom pirates.

Corrosive has done a good job putting out SDR and radio related videos over the past couple of weeks so it may be a channel to subscribe to if you are interested in this type of content.

Using National Weather Service Stations for Forward Scatter Meteor Detection

Over on his blog Dave Venne has been documenting his attempts at using National Weather Service (NWS) broadcasts for forward scatter meteor detection with an RTL-SDR. Forward scatter meteor detection is a passive method for detecting meteors as they enter the atmosphere. When a meteor enters the atmosphere it leaves behind a trail of highly RF reflective ionized air. This ionized air can reflect far away signals from strong transmitters directly into your receiving antenna, thus detecting a meteor.

Typically signals from analog TV and broadcast FM stations are preferred as they are near the optimal frequency for reflection of the ionized trails. However, Dave lives in an area where the broadcast FM spectrum is completely saturated with signals, leaving no empty frequencies to detect meteors. Instead Dave decided to try and use NWS signals at 160 MHz. In the USA there are seven frequencies for NWS and they are physically spaced out so that normally only one transmitter can be heard. Thus tuning to a far away station should produce nothing but static unless a meteor is reflecting its signal. Dave however does note that the 160 MHz frequency is less than optimal for detection and you can expect about 14 dB less reflected signal from meteors.

So far Dave has been able to detect several ‘blips’ with his cross-dipole antenna, RTL-SDR and SDR#. He also uses the Chronolapse freeware software to perform timelapse screenshots of the SDR# waterfall, so that the waterfall can be reviewed later. Unfortunately, most of the blips appear to have been aircraft as they seem to coincide with local air activity, and exhibit a Doppler shift characteristic that is typical of aircraft. He notes that the idea may still work for others who do not live near an airport.

A possible meteor detection in SDR#.
A possible meteor detection in SDR#.
Aircraft detection doppler
Aircraft detection doppler

We note that if you are interested in detecting aircraft via passive forward scatter and their Doppler patterns, then this previous post on just that may interest you.

Talking to Ghosts with an RTL-SDR Dongle

Back in November of last year we posted about Doug Haber’s gqrx-ghostbox which is software that turns your RTL-SDR into an electronic voice phenomenon (EVP) tool, or in other words a ‘ghost box’ or ‘spirit box’. A ghost box is essentially a device that rapidly tunes between broadcast radio stations, creating mismashed audio of multiple stations. Paranormal researchers believe that such a tool can be used to communicate with ghosts or spirits. Over on Amazon commercial ghost boxes/spirit boxes seem to retail for anywhere from $70 USD to $140 USD so an RTL-SDR can be a budget way to get into paranormal research.

Over on her blog paranormal investigator shielaaliens has uploaded a post and video demonstrating an RTL-SDR based ghost box in action. Sheila actually doesn’t use the grqx-ghostbox software, but instead she just uses SDR# with a frequency scanner plugin set to rapidly scan through the broadcast band. In the video she asks the SDR# ghost box a few control questions such as “can you say kitty cat” and “can you say Nantucket”. In response the SDR# ghost box appears to respond with those exact words. Her Facebook post with the video can be found here.

Of course this might all sound pretty far fetched for most readers of this blog, but it is an application that the RTL-SDR is now being used for nonetheless!

SDR-Console V3 Latest Update: Signal History & Receiver Panes

SDR-Console is a popular RTL-SDR compatible multi purpose SDR software package which is similar to programs like SDR#, HDSDR and SDRuno. Currently SDR-Console V2 is the stable version and SDR-Console V3 is in a beta state. A few days ago SDR-Console V3 Preview 6 was released. It comes with some very interesting new features including a built in Airspy server, a recording scheduler, a new feature called signal history and a new receivers pane.

Over on his blog Nils Schiffhauer (DK8OK) has been reviewing the new release of SDR-Conosle V3 and writes the following information about some of the new features:

  • “Signal History” takes the signal strength of the given bandwidth each 50 milliseconds, which can be saved in a CSV file. It is also shown in three different speeds on a display.
  • “Receivers’ Pane” shows up to six combos of spectrum/spectrogram of the complete up to 24 parallel demodulators (they additionally can be shown in the Matrix, as in former versions).

“Signal History” offers many applications, to name just three:

  • analyze fading and its structure with an unsurpassed time resolution of 50 ms
  • document fade-in and fade out
  • measure signal-to-noise ratio of signals

In addition Nils has also uploaded a very useful 19 page PDF where he writes step by step instructions and shows numerous examples of the new signal history tool.

DK8OK's SDR-Console V3 P6 Screenshot. Showing multiple receiver panes and the new signal history feature.
DK8OK’s SDR-Console V3 P6 Screenshot. Showing multiple receiver panes and the new signal history feature.
DK8OK's screenshot of the signal history toolbox.
DK8OK’s screenshot of the signal history toolbox.

Testing the Outernet Dreamcatcher: Linux Based ARM PC with Built in RTL-SDR

Last week we posted about Outernet’s new Dreamcatcher unit which is an RTL-SDR + L-band LNA + computing board all on the same PCB. The Dreamcatcher comes with a new active ceramic L-band patch antenna, costs $99 USD (plus shipping) and can be bought directly from their store. Outernet were kind enough to send us a review unit, and we’ve been testing it for the past few weeks. This post is a review of the unit.

Background

Outernet is a free data service that uses L-band satellites to beam down information like news, weather updates, Wikipedia articles, books and more.

In the past Outernet have used the $9 USD C.H.I.P computing board, an RTL-SDR dongle and an external LNA as the receiving hardware for their data service. However, popularity of the Outernet service has been severely hindered by the huge supply shortages of the C.H.I.P. Over the past year or so it has been almost impossible to get a hold of a C.H.I.P unit if you did not back the Kickstarter or buy one from Outernet’s first initial stock. By manufacturing their own PCB including the computing hardware, Outernet must be hoping to be able to control their stock situation, and not rely on third parties who may not be able to deliver.

At the moment the Dreamcatcher can only be run on their new Armbian image. The older Skylark image has been removed from their servers presumably because the Outernet signal is going to change in the near future and the old demodulator on Skylark may no longer work. The Armbian image is basically just standard Armbian and at the moment does not actually run any Outernet software, and cannot decode their signal, but this is being worked on. Eventually they hope to replace Skylark with a standard decoding app that runs on Armbian.

In this post we’ll review the Dreamcatcher with Armbian and consider it as a general purpose receiver (not just for Outernet), and we’ll also review the new active ceramic patch antenna as well.

Dreamcatcher Overview

The Dreamcatcher is a single PCB that combines an RTL-SDR, Linux (Armbian) based computing hardware, and an L-band LNA and filter. 

On first impressions we noticed that the PCB is relatively large square at about 12 cm by 12 cm. The most prominent chip is the Allwinner A13 SoC. The RTL-SDR circuitry is positioned in the upper right with the RF sections (R820T and LNA) both covered with RF shielding cans. There is no onboard WiFi circuitry, but a small ‘EDUP’ branded WiFi dongle is included and plugs into one of the USB ports on the PCB.

We measured the Dreamcatcher to be using about 400 mA – 600 mA while idle and 800 mA while utilizing the RTL-SDR and 100% CPU. Heat is not an issue as the Dreamcatcher stays relatively cool during its operation even at 100% CPU with the CPU only getting up to about 45 degrees C.

Continue reading

Forum Talk Videos From Hamvention 2017

During Hamvention 2017 several presenters and myself presented SDR or radio related talks. Some were filmed and put up onto YouTube. Unfortunately the 2017 SDR Forum video seems to be missing, or not yet uploaded yet.

The first set of talks was recorded by Gary KN4AQ at the TAPR Forum. The first talk in the set was from Michael Ossmann and Dominic Spill on “Low Cost, Open Source Spectrum Monitoring”. In this talk they discussed their recent improvements on creating a fast spectrum scanner mode on their HackRF. The second talk was “Advanced SDR Algorithms for Noise Blanking and Noise Reduction” by Warren Pratt NR0V. Here Warren discussed and gave examples of the effectiveness of some new noise blanker and noise reduction algorithms used in openHPSDR. Finally the third talk was “Introduction to RTL-SDR: Ultra cheap software defined radio” by Carl Laufer (myself). This was a brief introduction to the RTL-SDR showing some typical applications that they are used for.

The second set of talks was recorded by the Ham Radio 2.0 YouTube channel at the Digital Modes forum. The first talk was from myself again and was another introduction to cheap SDRs with some slightly different material. The second talk was by Uli with Wireless Holdings who discussed the latest developments in his DV4 digital mode transceiver products. Finally Mel K0PFX gave a talk on the latest developments in the FreeDV digital voice codec.

Finally I was interviewed by Gary KN4AQ of the HamRadioNow podcast and YouTube show and Marty KC1CWF of the PhasingLine podcast about RTL-SDR.com and the V3 dongles.

Just a reminder that slides from all the talks presented by myself are available on this post.