Category: Airband

Testing the Airspy with the New And Improved Version of ADSBSpy

Airspy have recently released an update to their ADSBspy decoder, which is an Airspy One/R2 compatible decoder for 1090 MHZ ADS-B signals. According to 'prog', the software developer of ADSBSpy, his setup can see almost double the number of aircraft and with fewer false positives when using the updated software. Prog writes that the secret to the improvement is some reworked DSP code that aims to exploit oversampling in the Airspy to the maximum.

We compared the new (1.0.0.38/39) decoder against the old decoder (1.0.0.37) which used to get similar performance to dump1090. The test setup was two Airspy dongles connected to a dipole antenna via a splitter, with our Triple Filtered ADS-B LNA used by the antenna. One Airspy was used to power the LNA via it's bias tee, and both units received the same amplified signal. We found indeed that the new version of ADSBSpy receives a good number more aircraft in our set up, and an increased number of ADS-B messages too.

It seems that most of the additionally received aircraft must be from extremely weak signals, because when looking in Virtual Radar Server the extra aircraft usually only show their ICAO and maybe altitude and speed until they get closer.

So far this software appears to provide the best performance on ADS-B that we've seen so far, so if you are using an Airspy for ADS-B tracking we'd like to hear results from anyone who upgrades.

The New ADS-B Spy Receives More Aircraft and Messages
The New ADS-B Spy Receives More Aircraft and Messages

PiAware Radar – A Traditional Radar-Like Display for ADS-B, and Setting up an ADS-B Cockpit Flight Display

PiAware Radar is a Python script that connects to your PiAware server and uses the received ADS-B data to display a familiar radar-like display (green circle with rotating radius, and aircraft displayed as blips). PiAware is the software used to take ADS-B data from an RTL-SDR dongle running on a Raspberry Pi and feed flightaware.com. A radar-like display is probably not very useful, but it could be used to set up an interesting display that might impress friends. Over on his blog IT9YBG has uploaded a tutorial that shows how to set PiAware Radar up on a Raspberry Pi.

Also on his blog IT9YBG has uploaded another tutorial that shows how to set up 1090XHSI, which is a program that displays an 737 aircraft cockpit simulation using live ADS-B data. The ADS-B data updates the instrument displays in real time, giving you a view of exactly what the pilots might be seeing on their dashboard of their aircraft. We posted about this software in the past, but IT9YBG's tutorial helps make it much easier to set up.

PiAware Radar
PiAware Radar
1090 XHSI 737 Cockpit Simulation from ADS-B Data
1090 XHSI 737 Cockpit Simulation from ADS-B Data

Radio For Everyone: Testing the RTL-SDR.com Triple Filtered ADS-B LNA, Amplified Coketenna

Akos, author of his blog 'Radio for Everyone' has recently reviewed our new RTL-SDR.com Triple Filtered ADS-B LNA. In the review he compares our ADS-B LNA against another external ADS-B LNA by Uputronics and against the FlightAware Prostick and Prostick+. The tests use the external LNA's plugged directly into the dongle in order to more fairly compare against the FlightAware dongles which have LNA's built in to the dongles themselves. From his results the RTL-SDR.com ADS-B LNA appears to have near identical results with the Uputronics LNA, and slightly better results compared to the FlightAware dongles. Akos has not yet tested the main use-case of the LNA, which is to use it at the end of a run of coax cable, however he plans to do this in a future test. Also in his second post Akos shows how to build a simple amplified Coketenna using our ADS-B LNA.

On the subject of ADS-B performance we note that there are two ways to set up a system for optimal reception (apart from the antenna). The first is to place the computing and radio devices (such as a Raspberry Pi and RTL-SDR) as close to the antenna as possible (leaving a ~1m coax run to avoid local interference from the Pi). For this type of setup it is cheaper to use a FlightAware Prostick Plus RTL-SDR dongle since this has an ADS-B LNA built into it. However, the disadvantage is that you may need to set up a Power over Ethernet system, or find a remote power source, and possibly place the Pi in a difficult to service location such as in an attic or up a mast.

The second option is to use an external ADS-B LNA close to the antenna, and run coax down to the computing device which is positioned in a more accessible location. The LNA will negate any losses in the coax cable, and with high enough gain on the LNA, using quality coax is not such a high requirement since those losses are negated by sufficient LNA gain. Both methods will yield similar excellent performance.

Tested ADS-B LNA's and ADS-B RTL-SDR Dongles
Tested ADS-B LNA's and ADS-B RTL-SDR Dongles

Listening to SELCAL and the HF Air Band with an RTL-SDR

Over on YouTube content creator Tech Minds continues to upload informative RTL-SDR based videos, this time discussing SELCAL and the HF Air Band. For international flights it is common for aircraft to communicate with ground controllers and the parent company via the HF bands.

As radio communications are sparse, and the pilots obviously don't want to monitor noisy HF static for the entirely journey a system is required for signalling pilots when a ground station wishes to communicate with them. The system in use today is SELCAL which simply consists of transmitting a set of tones unique to an aircraft. When a correct SELCAL tone is received the aircraft system alerts the pilots that a radio voice communication is about to come through, allowing them time to get the radio in operation. 

Tech Minds' video explains this in a bit more detail, and shows some examples of HF air comms with SELCAL tones played.

RTLSDR-Airband V3 Released

Thanks to RTL-SDR.com reader Lee Donaghy for writing in and little us know that RTLSDR-Airband was recently updated to include SoapySDR support. This allows the software to now work with almost any SDR including the RTL-SDR, Airspy, SDRplay, HackRF, LimeSDR and more. They have also removed the 8-channels per device limitation and applied various bug fixes too. The full changelog is posted at the end of this post.

RTLSDR-Airband is a Linux based command line tool that allows you to simultaneously monitor multiple AM or FM channels per SDR within the same chunk of bandwidth. It is great for monitoring narrowband communications such as aircraft control and can be used to feed websites like liveatc.net, or for use with a Icecast server, or simply for continuously recording multiple channels to an MP3 file locally. It is also very useful for those running on low powered computing hardware who want software that uses less CPU power than a full GUI program like GQRX or CubicSDR.

Version 3.0.0 (Feb 10, 2018):

  • Major overhaul of the SDR input code - now it's modular and hardware-agnostic (no longer tightly coupled with librtlsdr).
  • Support for SoapySDR vendor-neutral SDR library - any SDR which has a plugin for SoapySDR shall now work in RTLSDR-Airband.
  • Support for Mirics DVB-T dongles via libmirisdr-4 library.
  • Support for RTLSDR is now optional and can be disabled at compilation stage.
  • Removed the 8-channels-per-device limit in multichannel mode.
  • Configurable per-device sampling rate.
  • Configurable FFT size.
  • Support for multibyte input samples.
  • Support for rawfile outputs (ie. writing raw I/Q data from a narrowband channel to a file for processing with other programs, line GNUradio or csdr).
  • INCOMPATIBLE CHANGE: removed rtlsdr_buffers global configuration option; buffer count can now be adjusted with a per-device "buffers" option.
  • INCOMPATIBLE CHANGE: removed syslog global configuration option; syslog logging is now enabled by default, both in foreground and background mode. To force logging to standard error, use -e command line option.
  • Added -F command line option for better cooperation with systemd. Runs the program in foreground, but without textual waterfalls. Together with -e it allows running rtl_airband as a service of type "simple" under systemd. Example rtl_airband.service file has been adjusted to reflect this change.
  • Added type device configuration option. It sets the device type (ie. the input driver which shall be used to talk to the device). "rtlsdr" is assumed as a default type for backward compatibility. If RTLSDR support has been disabled at compilation stage, then there is no default type - it must be set manually, or the program will throw an error on startup.
  • Frequencies in the config can now be expressed in Hz, kHz, MHz or GHz for improved readability.
  • Lots of bugfixes.
  • Rewritten documentation on Github Wiki.

Running a NAS, Torrentbox and ADS-B RTL-SDR Server all on the same Raspberry Pi 3

Most readers are familiar with the Raspberry Pi 3 and how it can be used with RTL-SDR applications such as ADS-B reception. However, one does not need to dedicate an entire Pi 3 to a single task as they are more than powerful enough to run multiple applications at once.

Over on his blog 'Radio for Everyone' Akos has uploaded a tutorial that shows how he set his Raspberry Pi 3 up as a simultaneous Network Attached Storage (NAS), Torrentbox  and ADS-B server. A NAS is simply a hard drive or other data storage device that can be accessed easily over a network instead of having to be connected directly to a PC. A torrentbox is a device such as a Raspberry Pi 3 running torrent software so that you can download torrent files 24/7 without needing a PC on all the time.

Akos' tutorial shows how to set everything up from scratch, starting from writing the Raspbian SD Card and connecting to it via SSH. He then goes on to show how to install the torrent software, set up the NAS and finally set up ADS-B reception.

Pi 3 as a NAS, torrentbox and ADS-B server.
Pi 3 as a NAS, torrentbox and ADS-B server.

New Product: RTL-SDR Blog 1090 MHz ADS-B LNA

We're happy to announce the release of our new high performance low noise amplifier (LNA) for improving 1090 MHz ADS-B reception. The LNA uses a low noise figure high linearity two stage MGA-13116 amplifier chip and three stages of filtering to ensure that strong signals or interference will not overload either the amplifier or SDR dongle.

The LNA is currently only available from our Chinese warehouse, and costs US$24.95 including shipping. Please note that the price may increase slightly in the future, and that Amazon USA may not be stocked until March.

Click here to visit our store

RTLBlog_LNA_Product_Flat
RTLBlog_LNA_Product_PCB_Flat

An LNA can help improve ADS-B reception by reducing the noise figure of the system and by helping to overcome losses in the coax cable and/or any other components such as switches and connector in the signal path. To get the best performance from an LNA, the LNA needs to be positioned close to the antenna, before the coax to the radio.

The gain of the RTL-SDR Blog ADS-B LNA is 27 dB's at 1090 MHz, and out of band signals are reduced by at least 60 - 80 dB's. Attenuation in the broadcast FM band and below 800 MHz is actually closer to over 100 dB's. In the LNA signal path there is first a low insertion loss high pass filter that reduces the strength of any broadcast FM, TV, pager or other similar signals that are usually extremely strong. Then in between the first and second stage of the LNA is a SAW filter tuned for 1090 MHz. A second SAW filter sits on the output of the LNA. The result is that strong out of band signals are significantly blocked, yet the LNA remains effective at 1090 MHz with a low ~1 dB noise figure.

The LNA is also protected against ESD damage with a gas discharge tube and low capacitance ESD diode. But please always remember that your antenna must also be properly grounded to prevent ESD damage.

Finally please note that this LNA requires bias tee power to work. Bias tee power is when the DC power comes through the coax cable. The RTL-SDR V3 has bias tee power built into it and this can be activated in software. See the V3 users guide for information on how to activate it. Alternatively if you don't own a dongle with bias tee built in, then an external bias tee can be used and those can be found fairly cheaply on eBay. Finally, if you are confident with soldering SMT components, then there are also pads and a 0 Ohm resistor slot on the PCB to install an LDO and power the LNA directly.

Specification Summary:

  • Frequency: 1090 MHz
  • Gain: 27 dB @ 1090 MHz
  • Return Loss: -16 dB @ 1090 MHz (SWR = 1.377)
  • Noise Figure: ~1 dB
  • Out of band attenuation: More than 60 dB
  • ESD Protection: Dual with GDT and ESD Diode
  • Power: 3.3 - 5V via bias tee only, 150 mA current draw
  • Enclosure: Aluminum enclosure
  • Connectors: Two SMA Female (Male to Male adapter included)

Dimensions:

46.5 x 32 x 15.6 mm (not including the SMA).
Including the SMA the length is 69.8 mm.

Testing

We tested our new LNA against another ADS-B LNA with filter built in that is sold by another company and the FlightAware Prostick+ dongle in an environment with strong out of band signals such as pagers, broadcast FM, DVB-T and GSM signals. The results showed that the RTL-SDR Blog ADS-B LNA gathered the most ADS-B packets. In the tests both LNA's were connected on the receiver side to be fair to the FA dongle. Improved performance could be achieved by moving the LNA to the antenna side.

Other ADS-B LNA vs RTL-SDR Blog ADS-B LNA Received Messages
FlightAware Prostick+ vs RTL-SDR Blog ADS-B LNA Received Messages

Checking in SDR# for out of band signals also showed that the RTL-SDR Blog ADS-B LNA significantly reduces those strong out of band signals, whereas the others have trouble blocking them out. Below we show the results as well as some measurements.

RTL Blog ADS-B LNA @ 1090 MHz

RTL Blog ADS-B LNA @ 1090 MHz

Other ADS-B LNA @ 1090 MHz

Other ADS-B LNA @ 1090 MHz

FlightAware Prostick+ @ 1090 MHz

FlightAware Prostick+ @ 1090 MHz

RTL Blog ADS-B LNA tuned to Broadcast FM

RTL Blog ADS-B LNA tuned to Broadcast FM

Other ADS-B LNA tuned to Broadcast FM

Other ADS-B LNA tuned to Broadcast FM

FlightAware Protstick+ tuned to Broadcast FM

FlightAware Protstick+ tuned to Broadcast FM

RTL Blog ADS-B LNA tuned to a DVB-T Signal

RTL Blog ADS-B LNA tuned to a DVB-T Signal

Other ADS-B LNA tuned to a DVB-T Signal

Other ADS-B LNA tuned to a DVB-T Signal

FlightAware Prostick+ tuned to a DVB-T Signal

FlightAware Prostick+ tuned to a DVB-T Signal

RTL Blog ADS-B LNA tuned to a GSM Signal

RTL Blog ADS-B LNA tuned to a GSM Signal

Other ADS-B LNA tuned to a GSM Signal

Other ADS-B LNA tuned to a GSM Signal

FlightAware Prostick+ tuned to a GSM Signal

FlightAware Prostick+ tuned to a GSM Signal

Gain Measurements

Gain Measurements

Return Loss

Return Loss

Simulated Gain/Attenuation

Simulated Gain/Attenuation

Conclusion

This RTL-SDR Blog ADS-B LNA can significantly improve ADS-B reception, especially if you are in an environment with strong out of band signals. Even if you are not, the low noise figure design will improve reception regardless.

Testing the Airspy with the New And Improved Version of ADSBSpy

Airspy have recently released an update to their ADSBspy decoder, which is an Airspy One/R2 compatible decoder for 1090 MHZ ADS-B signals. According to 'prog', the software developer of ADSBSpy, his setup can see almost double the number of aircraft and with fewer false positives when using the updated software. Prog writes that the secret to the improvement is some reworked DSP code that aims to exploit oversampling in the Airspy to the maximum.

We compared the new (1.0.0.38/39) decoder against the old decoder (1.0.0.37) which used to get similar performance to dump1090. The test setup was two Airspy dongles connected to a dipole antenna via a splitter, with our Triple Filtered ADS-B LNA used by the antenna. One Airspy was used to power the LNA via it's bias tee, and both units received the same amplified signal. We found indeed that the new version of ADSBSpy receives a good number more aircraft in our set up, and an increased number of ADS-B messages too.

It seems that most of the additionally received aircraft must be from extremely weak signals, because when looking in Virtual Radar Server the extra aircraft usually only show their ICAO and maybe altitude and speed until they get closer.

So far this software appears to provide the best performance on ADS-B that we've seen so far, so if you are using an Airspy for ADS-B tracking we'd like to hear results from anyone who upgrades.

The New ADS-B Spy Receives More Aircraft and Messages
The New ADS-B Spy Receives More Aircraft and Messages

PiAware Radar – A Traditional Radar-Like Display for ADS-B, and Setting up an ADS-B Cockpit Flight Display

PiAware Radar is a Python script that connects to your PiAware server and uses the received ADS-B data to display a familiar radar-like display (green circle with rotating radius, and aircraft displayed as blips). PiAware is the software used to take ADS-B data from an RTL-SDR dongle running on a Raspberry Pi and feed flightaware.com. A radar-like display is probably not very useful, but it could be used to set up an interesting display that might impress friends. Over on his blog IT9YBG has uploaded a tutorial that shows how to set PiAware Radar up on a Raspberry Pi.

Also on his blog IT9YBG has uploaded another tutorial that shows how to set up 1090XHSI, which is a program that displays an 737 aircraft cockpit simulation using live ADS-B data. The ADS-B data updates the instrument displays in real time, giving you a view of exactly what the pilots might be seeing on their dashboard of their aircraft. We posted about this software in the past, but IT9YBG's tutorial helps make it much easier to set up.

PiAware Radar
PiAware Radar
1090 XHSI 737 Cockpit Simulation from ADS-B Data
1090 XHSI 737 Cockpit Simulation from ADS-B Data

Radio For Everyone: Testing the RTL-SDR.com Triple Filtered ADS-B LNA, Amplified Coketenna

Akos, author of his blog 'Radio for Everyone' has recently reviewed our new RTL-SDR.com Triple Filtered ADS-B LNA. In the review he compares our ADS-B LNA against another external ADS-B LNA by Uputronics and against the FlightAware Prostick and Prostick+. The tests use the external LNA's plugged directly into the dongle in order to more fairly compare against the FlightAware dongles which have LNA's built in to the dongles themselves. From his results the RTL-SDR.com ADS-B LNA appears to have near identical results with the Uputronics LNA, and slightly better results compared to the FlightAware dongles. Akos has not yet tested the main use-case of the LNA, which is to use it at the end of a run of coax cable, however he plans to do this in a future test. Also in his second post Akos shows how to build a simple amplified Coketenna using our ADS-B LNA.

On the subject of ADS-B performance we note that there are two ways to set up a system for optimal reception (apart from the antenna). The first is to place the computing and radio devices (such as a Raspberry Pi and RTL-SDR) as close to the antenna as possible (leaving a ~1m coax run to avoid local interference from the Pi). For this type of setup it is cheaper to use a FlightAware Prostick Plus RTL-SDR dongle since this has an ADS-B LNA built into it. However, the disadvantage is that you may need to set up a Power over Ethernet system, or find a remote power source, and possibly place the Pi in a difficult to service location such as in an attic or up a mast.

The second option is to use an external ADS-B LNA close to the antenna, and run coax down to the computing device which is positioned in a more accessible location. The LNA will negate any losses in the coax cable, and with high enough gain on the LNA, using quality coax is not such a high requirement since those losses are negated by sufficient LNA gain. Both methods will yield similar excellent performance.

Tested ADS-B LNA's and ADS-B RTL-SDR Dongles
Tested ADS-B LNA's and ADS-B RTL-SDR Dongles

Listening to SELCAL and the HF Air Band with an RTL-SDR

Over on YouTube content creator Tech Minds continues to upload informative RTL-SDR based videos, this time discussing SELCAL and the HF Air Band. For international flights it is common for aircraft to communicate with ground controllers and the parent company via the HF bands.

As radio communications are sparse, and the pilots obviously don't want to monitor noisy HF static for the entirely journey a system is required for signalling pilots when a ground station wishes to communicate with them. The system in use today is SELCAL which simply consists of transmitting a set of tones unique to an aircraft. When a correct SELCAL tone is received the aircraft system alerts the pilots that a radio voice communication is about to come through, allowing them time to get the radio in operation. 

Tech Minds' video explains this in a bit more detail, and shows some examples of HF air comms with SELCAL tones played.

RTLSDR-Airband V3 Released

Thanks to RTL-SDR.com reader Lee Donaghy for writing in and little us know that RTLSDR-Airband was recently updated to include SoapySDR support. This allows the software to now work with almost any SDR including the RTL-SDR, Airspy, SDRplay, HackRF, LimeSDR and more. They have also removed the 8-channels per device limitation and applied various bug fixes too. The full changelog is posted at the end of this post.

RTLSDR-Airband is a Linux based command line tool that allows you to simultaneously monitor multiple AM or FM channels per SDR within the same chunk of bandwidth. It is great for monitoring narrowband communications such as aircraft control and can be used to feed websites like liveatc.net, or for use with a Icecast server, or simply for continuously recording multiple channels to an MP3 file locally. It is also very useful for those running on low powered computing hardware who want software that uses less CPU power than a full GUI program like GQRX or CubicSDR.

Version 3.0.0 (Feb 10, 2018):

  • Major overhaul of the SDR input code - now it's modular and hardware-agnostic (no longer tightly coupled with librtlsdr).
  • Support for SoapySDR vendor-neutral SDR library - any SDR which has a plugin for SoapySDR shall now work in RTLSDR-Airband.
  • Support for Mirics DVB-T dongles via libmirisdr-4 library.
  • Support for RTLSDR is now optional and can be disabled at compilation stage.
  • Removed the 8-channels-per-device limit in multichannel mode.
  • Configurable per-device sampling rate.
  • Configurable FFT size.
  • Support for multibyte input samples.
  • Support for rawfile outputs (ie. writing raw I/Q data from a narrowband channel to a file for processing with other programs, line GNUradio or csdr).
  • INCOMPATIBLE CHANGE: removed rtlsdr_buffers global configuration option; buffer count can now be adjusted with a per-device "buffers" option.
  • INCOMPATIBLE CHANGE: removed syslog global configuration option; syslog logging is now enabled by default, both in foreground and background mode. To force logging to standard error, use -e command line option.
  • Added -F command line option for better cooperation with systemd. Runs the program in foreground, but without textual waterfalls. Together with -e it allows running rtl_airband as a service of type "simple" under systemd. Example rtl_airband.service file has been adjusted to reflect this change.
  • Added type device configuration option. It sets the device type (ie. the input driver which shall be used to talk to the device). "rtlsdr" is assumed as a default type for backward compatibility. If RTLSDR support has been disabled at compilation stage, then there is no default type - it must be set manually, or the program will throw an error on startup.
  • Frequencies in the config can now be expressed in Hz, kHz, MHz or GHz for improved readability.
  • Lots of bugfixes.
  • Rewritten documentation on Github Wiki.

Running a NAS, Torrentbox and ADS-B RTL-SDR Server all on the same Raspberry Pi 3

Most readers are familiar with the Raspberry Pi 3 and how it can be used with RTL-SDR applications such as ADS-B reception. However, one does not need to dedicate an entire Pi 3 to a single task as they are more than powerful enough to run multiple applications at once.

Over on his blog 'Radio for Everyone' Akos has uploaded a tutorial that shows how he set his Raspberry Pi 3 up as a simultaneous Network Attached Storage (NAS), Torrentbox  and ADS-B server. A NAS is simply a hard drive or other data storage device that can be accessed easily over a network instead of having to be connected directly to a PC. A torrentbox is a device such as a Raspberry Pi 3 running torrent software so that you can download torrent files 24/7 without needing a PC on all the time.

Akos' tutorial shows how to set everything up from scratch, starting from writing the Raspbian SD Card and connecting to it via SSH. He then goes on to show how to install the torrent software, set up the NAS and finally set up ADS-B reception.

Pi 3 as a NAS, torrentbox and ADS-B server.
Pi 3 as a NAS, torrentbox and ADS-B server.

New Product: RTL-SDR Blog 1090 MHz ADS-B LNA

We're happy to announce the release of our new high performance low noise amplifier (LNA) for improving 1090 MHz ADS-B reception. The LNA uses a low noise figure high linearity two stage MGA-13116 amplifier chip and three stages of filtering to ensure that strong signals or interference will not overload either the amplifier or SDR dongle.

The LNA is currently only available from our Chinese warehouse, and costs US$24.95 including shipping. Please note that the price may increase slightly in the future, and that Amazon USA may not be stocked until March.

Click here to visit our store

RTLBlog_LNA_Product_Flat
RTLBlog_LNA_Product_PCB_Flat

An LNA can help improve ADS-B reception by reducing the noise figure of the system and by helping to overcome losses in the coax cable and/or any other components such as switches and connector in the signal path. To get the best performance from an LNA, the LNA needs to be positioned close to the antenna, before the coax to the radio.

The gain of the RTL-SDR Blog ADS-B LNA is 27 dB's at 1090 MHz, and out of band signals are reduced by at least 60 - 80 dB's. Attenuation in the broadcast FM band and below 800 MHz is actually closer to over 100 dB's. In the LNA signal path there is first a low insertion loss high pass filter that reduces the strength of any broadcast FM, TV, pager or other similar signals that are usually extremely strong. Then in between the first and second stage of the LNA is a SAW filter tuned for 1090 MHz. A second SAW filter sits on the output of the LNA. The result is that strong out of band signals are significantly blocked, yet the LNA remains effective at 1090 MHz with a low ~1 dB noise figure.

The LNA is also protected against ESD damage with a gas discharge tube and low capacitance ESD diode. But please always remember that your antenna must also be properly grounded to prevent ESD damage.

Finally please note that this LNA requires bias tee power to work. Bias tee power is when the DC power comes through the coax cable. The RTL-SDR V3 has bias tee power built into it and this can be activated in software. See the V3 users guide for information on how to activate it. Alternatively if you don't own a dongle with bias tee built in, then an external bias tee can be used and those can be found fairly cheaply on eBay. Finally, if you are confident with soldering SMT components, then there are also pads and a 0 Ohm resistor slot on the PCB to install an LDO and power the LNA directly.

Specification Summary:

  • Frequency: 1090 MHz
  • Gain: 27 dB @ 1090 MHz
  • Return Loss: -16 dB @ 1090 MHz (SWR = 1.377)
  • Noise Figure: ~1 dB
  • Out of band attenuation: More than 60 dB
  • ESD Protection: Dual with GDT and ESD Diode
  • Power: 3.3 - 5V via bias tee only, 150 mA current draw
  • Enclosure: Aluminum enclosure
  • Connectors: Two SMA Female (Male to Male adapter included)

Dimensions:

46.5 x 32 x 15.6 mm (not including the SMA).
Including the SMA the length is 69.8 mm.

Testing

We tested our new LNA against another ADS-B LNA with filter built in that is sold by another company and the FlightAware Prostick+ dongle in an environment with strong out of band signals such as pagers, broadcast FM, DVB-T and GSM signals. The results showed that the RTL-SDR Blog ADS-B LNA gathered the most ADS-B packets. In the tests both LNA's were connected on the receiver side to be fair to the FA dongle. Improved performance could be achieved by moving the LNA to the antenna side.

Other ADS-B LNA vs RTL-SDR Blog ADS-B LNA Received Messages
FlightAware Prostick+ vs RTL-SDR Blog ADS-B LNA Received Messages

Checking in SDR# for out of band signals also showed that the RTL-SDR Blog ADS-B LNA significantly reduces those strong out of band signals, whereas the others have trouble blocking them out. Below we show the results as well as some measurements.

RTL Blog ADS-B LNA @ 1090 MHz

RTL Blog ADS-B LNA @ 1090 MHz

Other ADS-B LNA @ 1090 MHz

Other ADS-B LNA @ 1090 MHz

FlightAware Prostick+ @ 1090 MHz

FlightAware Prostick+ @ 1090 MHz

RTL Blog ADS-B LNA tuned to Broadcast FM

RTL Blog ADS-B LNA tuned to Broadcast FM

Other ADS-B LNA tuned to Broadcast FM

Other ADS-B LNA tuned to Broadcast FM

FlightAware Protstick+ tuned to Broadcast FM

FlightAware Protstick+ tuned to Broadcast FM

RTL Blog ADS-B LNA tuned to a DVB-T Signal

RTL Blog ADS-B LNA tuned to a DVB-T Signal

Other ADS-B LNA tuned to a DVB-T Signal

Other ADS-B LNA tuned to a DVB-T Signal

FlightAware Prostick+ tuned to a DVB-T Signal

FlightAware Prostick+ tuned to a DVB-T Signal

RTL Blog ADS-B LNA tuned to a GSM Signal

RTL Blog ADS-B LNA tuned to a GSM Signal

Other ADS-B LNA tuned to a GSM Signal

Other ADS-B LNA tuned to a GSM Signal

FlightAware Prostick+ tuned to a GSM Signal

FlightAware Prostick+ tuned to a GSM Signal

Gain Measurements

Gain Measurements

Return Loss

Return Loss

Simulated Gain/Attenuation

Simulated Gain/Attenuation

Conclusion

This RTL-SDR Blog ADS-B LNA can significantly improve ADS-B reception, especially if you are in an environment with strong out of band signals. Even if you are not, the low noise figure design will improve reception regardless.

Tom’s Radio Room Tests and Reviews the RTL-SDR Blog Multipurpose Dipole Kit

Over on his YouTube channel Tom Stiles (hamrad88) has been experimenting with and reviewing our multipurpose dipole kit. Tom is a ham radio YouTuber who runs a show that produces content often, so we encourage you to subcribe to his channel if you're interested. Tom reviewed our dipole kit over a series of 5 videos which we link here [1: Discussing the product], [2: Unboxing], [3: First ADS-B Tests], [4: Second ADS-B Tests], [5: Third ADS-B Tests]. We post have embedded video 2 and 5 below.

In his testing Tom finds that using the antenna in the vertical orientation improves ADS-B performance. This is expected as ADS-B signals are vertically polarized, and so the antenna should be too. By using the included suction cup mount Tom is able to get the antenna attached to his window which improves reception by getting the antenna as close to the outdoors as possible. This is an expected use case for the antenna, and it's good to see that good results are being had!

If you're interested in the set please see our store at www.rtl-sdr.com/store, or use the links provided in Tom's videos. We also have a tutorial and use case demonstrations for our dipole kit available at www.rtl-sdr.com/DIPOLE.