Over on YouTube user Corrosive has uploaded a video where he takes us on a tour or his very nicely set up mobile SDR station that is built into his car. His setup includes several antennas on his car's roof which cover multiple bands, a BCD780XLT scanner, an RTL-SDR, an Android head unit that is capable of running multiple SDR apps and also a Windows tablet that is used to run more CPU heavy SDR apps.
Later in the video he shows himself running SDR Trunk on the tablet and receiving and decoding the local P25 police department signal, and then running dump1090 for monitoring aircraft ADS-B, and Gpredict for tracking satellites.
RTL SDR Mobile Car Station | Receive ADS-B ATCS P25 DMR POCSAG and More on the Go!
A radiosonde is a small weather sensor package that is typically attached to a weather balloon. As it rises into the atmosphere it measures parameters such as temperature, humidity, pressure, GPS location etc, and transmits this data back down to a receiver base station using a radio signal.
Zilog's RS is a free open source radiosonde decoder for Linux and it supports a wide range of radiosonde protocols. Together with an RTL-SDR it is possible to receive radiosonde signals, and decode them using RS.
Over on his website, happysat has recently uploaded a tutorial that shows how to use RS with an RTL-SDR, CubicSDR or GQRX, and FoxtrotGPS, a GPS plotting program for visualizing the location of the radiosonde. The tutorial covers some tricky points like setting up audio piping in Linux, and getting the GPS data into a virtual COM port to use with FoxtrotGPS.
Alternatively, there are also Windows GUI based sonde decoders that can be used with the RTL-SDR such as SondeMonitor which costs 25 Euros, but also covers a wide range of sonde protocols, and RS41 Decoder which is a GUI for the RS41 sonde protocol only. If you are interested we have a tutorial on setting up radiosonde decoding in Windows with SondeMonitor available here.
Plotting the Sonde Location with an RTL-SDR, GQRX, RS and FoxtrotGPS.
The designs include the PCB Gerber files for manufacturing, the components list and assembly and usage guides. Also both through-hole and SMD designs are provided.
The Mini-Whip design has a frequency range of 10 kHz - 30 MHz and to power it you'll need a 5 - 13V bias tee. You will need to install it up high and preferably away from the house as Mini-Whips are quite susceptible to local noise pickup. Another very important point is that Mini-Whips need to have a good ground connection. The upconverter is based on the ADE-1 mixer, and uses a 125 MHz local oscillator.
Igor's documentation on the project is excellent, and is a good read for getting more information about upconverters and Mini-Whips. He has noted that he is sending us some samples of units that he's built, so when we receive them we'll post again with test results. It looks as if he's put a lot of research into these designs so we're looking forward to seeing how well they work.
Diagram from Igor's documentation about how to properly ground a Mini-Whip connected to a metal mast.
Over on his YouTube channel Crazy Danish Hacker has posted a new video that shows how to pick up amateur radio voice signals from the International Space Station (ISS).
Often astronauts on the ISS will schedule times to chat with schools via amateur radio frequencies. This provides an opportunity to learn about radio whilst at the same time allowing kids to talk directly to an astronaut.
If you live in an area that can 'see' the ISS at the same time as the school then you can easily pick up the downlink (astronaut to ground) portion of the conversation while the ISS passes over. The downlink signal is fairly strong, so only a simple antenna is required. In his video Crazy Danish Hacker uses a telescopic whip attached directly to his RTL-SDR which is placed outside with a view of the sky.
International Space Station - Software Defined Radio Series #29
Most police departments is the USA have now upgraded or are in the process of upgrading their radio systems to P25 Phase 2 digital radio. The frequencies can easily be received with an RTL-SDR, but a decoder is required to be able to actually listen to the voice. Software like SDRTrunk and DSDPlus can decode P25 Phase 1, but at the moment the only software that is capable of decoding P25 Phase 1 AND 2 is a program called OP25. However, OP25 has a reputation of being fairly difficult to set up as it does not have a simple to use GUI, and requires Linux.
Over on John's Tech Blog, John has uploaded a very helpful step by step tutorial that should help with those trying to get OP25 to work. The tutorial assumes that you have Ubuntu 18.04 already installed, and then starts from downloading and installing OP25. The next steps involve setting up OP25 for the particular system in your area, which mostly involves just editing a spreadsheet to input frequency data from radioreference.com. John also mentions that he's been able to get OP25 running perfectly on a Raspberry Pi 3 B+ as well, with less than 40% CPU usage.
OP25 Running
In the video below John reviews some of the steps, and shows OP25 running and decoding voice.
Over on our forums one user luc4sss has been discussing a method for using RTL-SDR's and perhaps other SDR dongles remotely which does not rely on rtl_tcp, SpyServer or other SDR specific server software. Using an SDR remotely is advantageous because it can allow you to position the SDR closer to the antenna, which results in less signal loss from long runs of lossy coax cable.
Instead of rtl_tcp, luc4sss uses a program called VirtualHere, which is a server that can work with any USB device. It essentially allows you to use USB devices over a network with the remote device acting as if it was plugged directly into your remotely operated PC. The server can run on single board Linux computers like the Raspberry Pi and luc4sss has been using an $8 Orange Pi Zero 256 MB as his server.
With the VirtualHere software and RTL-SDR running on his Orange Pi Zero, he's able to connect to a remote RTL-SDR over his network. He writes that data usage is about 5 - 6 MB/s so a wired Ethernet connection or high quality WiFi connection would be required. In comparison rtl_tcp should use about the same amount of data, but server software with some compression and data saving techniques implemented like SpyServer use much less data and is efficient enough to be used over the internet.
We can see the VirtualHere software being very useful for use with RTL-SDR compatible programs that don't have rtl_tcp support, which is most of them. It should also be useful for other SDRs that don't have streaming server software available.
VirtalHere is not free as a license costs $49. But it does have a 10-day trial period which supports 1 device being shared at a time.
VirtualHere USB Network Server
Luc4sss has also uploaded a video on YouTube that shows him running the VirtualHere server and client, and connecting to the remote RTL-SDR with GQRX and dump1090. He also shows the data usage which is about 6 MB/s when running the RTL-SDR at 2.8 MSPS. Operation appears to be problem free and with almost entirely no latency as well.
RTL-SDR over Ethernet with VirtualHere Client/Server
Over on his YouTube channel Tech Minds has recently uploaded a video that demonstrates and shows how to use the rtl_433 software with an RTL-SDR to decode 433 MHz ISM band low power devices. Typically these devices include things like home wireless temperature and weather sensors, tire pressure sensors, remote controls, and other various sensors.
In the video he sets up an RTL-SDR and magmount antenna by his window and is able to receive data from several of his neighbors weather stations, and some car key remotes. He shows how to run the software on both Linux and on Windows.
How To Decode 433Mhz Low Power Devices Using RTL433 And A RTL-SDR Receiver
Over on our store we've just released two new products for sale. The first is a metal case upgrade kit for the SDRplay RSP1A. It is similar to the previous enclosure that we sold for the RSP1, but no longer comes with an included BCFM filter since the RSP1A has this filter built in as a software switchable option.
Instead we've included a portable 7 meter (23 feet) long wire antenna spool (Tecsun AN-03L) with SMA adapter, and an 11 cm to 48 cm adjustable SMA telescopic antenna. The 7 meter antenna is great for HF SWLing, and neatly rolls up into the spool for travelling. The telescopic antenna is a portable VHF/UHF antenna that can plug directly into the SMA port of the RSP1A. Both antennas fit neatly into the supplied semi-hardshell carry case. The set costs US$29.95 including shipping and is available on our store, and will be on US Amazon in a couple of weeks.
The second product is the portable antenna set just by itself. The set includes the 7m Tecsun AN-03L antenna spool, the mono plug to SMA adapter and the 11 cm to 48 cm telescopic antenna. It can be used on any SDR with SMA ports. The set costs US$11.95 and is also available on our store. It will also be on Amazon in a couple of weeks.
Over on YouTube user Corrosive has uploaded a video where he takes us on a tour or his very nicely set up mobile SDR station that is built into his car. His setup includes several antennas on his car's roof which cover multiple bands, a BCD780XLT scanner, an RTL-SDR, an Android head unit that is capable of running multiple SDR apps and also a Windows tablet that is used to run more CPU heavy SDR apps.
Later in the video he shows himself running SDR Trunk on the tablet and receiving and decoding the local P25 police department signal, and then running dump1090 for monitoring aircraft ADS-B, and Gpredict for tracking satellites.
RTL SDR Mobile Car Station | Receive ADS-B ATCS P25 DMR POCSAG and More on the Go!
A radiosonde is a small weather sensor package that is typically attached to a weather balloon. As it rises into the atmosphere it measures parameters such as temperature, humidity, pressure, GPS location etc, and transmits this data back down to a receiver base station using a radio signal.
Zilog's RS is a free open source radiosonde decoder for Linux and it supports a wide range of radiosonde protocols. Together with an RTL-SDR it is possible to receive radiosonde signals, and decode them using RS.
Over on his website, happysat has recently uploaded a tutorial that shows how to use RS with an RTL-SDR, CubicSDR or GQRX, and FoxtrotGPS, a GPS plotting program for visualizing the location of the radiosonde. The tutorial covers some tricky points like setting up audio piping in Linux, and getting the GPS data into a virtual COM port to use with FoxtrotGPS.
Alternatively, there are also Windows GUI based sonde decoders that can be used with the RTL-SDR such as SondeMonitor which costs 25 Euros, but also covers a wide range of sonde protocols, and RS41 Decoder which is a GUI for the RS41 sonde protocol only. If you are interested we have a tutorial on setting up radiosonde decoding in Windows with SondeMonitor available here.
Plotting the Sonde Location with an RTL-SDR, GQRX, RS and FoxtrotGPS.
The designs include the PCB Gerber files for manufacturing, the components list and assembly and usage guides. Also both through-hole and SMD designs are provided.
The Mini-Whip design has a frequency range of 10 kHz - 30 MHz and to power it you'll need a 5 - 13V bias tee. You will need to install it up high and preferably away from the house as Mini-Whips are quite susceptible to local noise pickup. Another very important point is that Mini-Whips need to have a good ground connection. The upconverter is based on the ADE-1 mixer, and uses a 125 MHz local oscillator.
Igor's documentation on the project is excellent, and is a good read for getting more information about upconverters and Mini-Whips. He has noted that he is sending us some samples of units that he's built, so when we receive them we'll post again with test results. It looks as if he's put a lot of research into these designs so we're looking forward to seeing how well they work.
Diagram from Igor's documentation about how to properly ground a Mini-Whip connected to a metal mast.
Over on his YouTube channel Crazy Danish Hacker has posted a new video that shows how to pick up amateur radio voice signals from the International Space Station (ISS).
Often astronauts on the ISS will schedule times to chat with schools via amateur radio frequencies. This provides an opportunity to learn about radio whilst at the same time allowing kids to talk directly to an astronaut.
If you live in an area that can 'see' the ISS at the same time as the school then you can easily pick up the downlink (astronaut to ground) portion of the conversation while the ISS passes over. The downlink signal is fairly strong, so only a simple antenna is required. In his video Crazy Danish Hacker uses a telescopic whip attached directly to his RTL-SDR which is placed outside with a view of the sky.
International Space Station - Software Defined Radio Series #29
Most police departments is the USA have now upgraded or are in the process of upgrading their radio systems to P25 Phase 2 digital radio. The frequencies can easily be received with an RTL-SDR, but a decoder is required to be able to actually listen to the voice. Software like SDRTrunk and DSDPlus can decode P25 Phase 1, but at the moment the only software that is capable of decoding P25 Phase 1 AND 2 is a program called OP25. However, OP25 has a reputation of being fairly difficult to set up as it does not have a simple to use GUI, and requires Linux.
Over on John's Tech Blog, John has uploaded a very helpful step by step tutorial that should help with those trying to get OP25 to work. The tutorial assumes that you have Ubuntu 18.04 already installed, and then starts from downloading and installing OP25. The next steps involve setting up OP25 for the particular system in your area, which mostly involves just editing a spreadsheet to input frequency data from radioreference.com. John also mentions that he's been able to get OP25 running perfectly on a Raspberry Pi 3 B+ as well, with less than 40% CPU usage.
OP25 Running
In the video below John reviews some of the steps, and shows OP25 running and decoding voice.
Over on our forums one user luc4sss has been discussing a method for using RTL-SDR's and perhaps other SDR dongles remotely which does not rely on rtl_tcp, SpyServer or other SDR specific server software. Using an SDR remotely is advantageous because it can allow you to position the SDR closer to the antenna, which results in less signal loss from long runs of lossy coax cable.
Instead of rtl_tcp, luc4sss uses a program called VirtualHere, which is a server that can work with any USB device. It essentially allows you to use USB devices over a network with the remote device acting as if it was plugged directly into your remotely operated PC. The server can run on single board Linux computers like the Raspberry Pi and luc4sss has been using an $8 Orange Pi Zero 256 MB as his server.
With the VirtualHere software and RTL-SDR running on his Orange Pi Zero, he's able to connect to a remote RTL-SDR over his network. He writes that data usage is about 5 - 6 MB/s so a wired Ethernet connection or high quality WiFi connection would be required. In comparison rtl_tcp should use about the same amount of data, but server software with some compression and data saving techniques implemented like SpyServer use much less data and is efficient enough to be used over the internet.
We can see the VirtualHere software being very useful for use with RTL-SDR compatible programs that don't have rtl_tcp support, which is most of them. It should also be useful for other SDRs that don't have streaming server software available.
VirtalHere is not free as a license costs $49. But it does have a 10-day trial period which supports 1 device being shared at a time.
VirtualHere USB Network Server
Luc4sss has also uploaded a video on YouTube that shows him running the VirtualHere server and client, and connecting to the remote RTL-SDR with GQRX and dump1090. He also shows the data usage which is about 6 MB/s when running the RTL-SDR at 2.8 MSPS. Operation appears to be problem free and with almost entirely no latency as well.
RTL-SDR over Ethernet with VirtualHere Client/Server
Over on his YouTube channel Tech Minds has recently uploaded a video that demonstrates and shows how to use the rtl_433 software with an RTL-SDR to decode 433 MHz ISM band low power devices. Typically these devices include things like home wireless temperature and weather sensors, tire pressure sensors, remote controls, and other various sensors.
In the video he sets up an RTL-SDR and magmount antenna by his window and is able to receive data from several of his neighbors weather stations, and some car key remotes. He shows how to run the software on both Linux and on Windows.
How To Decode 433Mhz Low Power Devices Using RTL433 And A RTL-SDR Receiver
Over on our store we've just released two new products for sale. The first is a metal case upgrade kit for the SDRplay RSP1A. It is similar to the previous enclosure that we sold for the RSP1, but no longer comes with an included BCFM filter since the RSP1A has this filter built in as a software switchable option.
Instead we've included a portable 7 meter (23 feet) long wire antenna spool (Tecsun AN-03L) with SMA adapter, and an 11 cm to 48 cm adjustable SMA telescopic antenna. The 7 meter antenna is great for HF SWLing, and neatly rolls up into the spool for travelling. The telescopic antenna is a portable VHF/UHF antenna that can plug directly into the SMA port of the RSP1A. Both antennas fit neatly into the supplied semi-hardshell carry case. The set costs US$29.95 including shipping and is available on our store, and will be on US Amazon in a couple of weeks.
The second product is the portable antenna set just by itself. The set includes the 7m Tecsun AN-03L antenna spool, the mono plug to SMA adapter and the 11 cm to 48 cm telescopic antenna. It can be used on any SDR with SMA ports. The set costs US$11.95 and is also available on our store. It will also be on Amazon in a couple of weeks.
