Over on Reddit user u/isysopi201 has put up a fun post showing what an RTL-SDR Blog V3 looks like under an X-Ray machine. With the full resolution images, it is possible to see the PCB traces in internal planes, the windings on the electrolytic capacitor, inductors, USB choke and direct sampling matching transformer, as well as the bond wires on the RTL2832U and R820T2 silicon chips that connect the pins to the silicon.
Thank you to Rodrigo Freire (PY2RAF) for submitting his project that has cleanly turned a standard Yaesu FT-991A ham radio into an RTL-SDR based software defined radio panadapter with no external wires, hubs or dongles.
Rodrigo's system consists of an IF tap amplifier+filter board that is connected to an internally mounted RTL-SDR. The RTL-SDR is internally connected to the FT-991A's USB hub which had to be upgraded from a 2-port hub to a 4-port hub as the 2-ports were already in use by the CAT and Audio features. This required the stock USB hub IC to be replaced with a hot air rework station.
Everything is mounted inside the radio chassis itself, and the end result is a neat solution with no external wires, hubs or dongles that has essentially turned the FT-991A into an SDR. Plugging in the single stock USB cable from the FT-991A results in the standard CAT and Audio interfaces showing up, as well as the RTL-SDR.
What's also interesting is that Rodrigo makes use of the GPIO pins on our RTL-SDR Blog V3 to enable the RX_EN, BPF and BYPASS switches on the IF tap board. This allows for a cleaner solution as no external switches need to be installed.
This week on the SignalsEverywhere YouTube channel Harold shows us the mobile SDR and ham radio setup that he's installed on his car. On the roof of his car he's installed several antennas for various amateur radio bands including the 1.25m, 2m, 70cm, 33cm bands, a modified GPS puck antenna for Inmarsat and Iridium reception, and an antenna and GPS pick dedicated for APRS.
Inside the vehicle is a Windows tablet attached to the dashboard which is used for APRS, remotely controlling a scanner radio stored in the trunk and for running SDRSharp. There is also an Android unit installed in the center console which has an RTL-SDR connected. The Android unit runs RF Analyzer, and an ADS-B decoder. As well as SDRs, Harold also runs several standard ham radios within the vehicle.
Arun Venkataswamy has recently completed a write up about his system which automatically captures images of passing aircraft. It works by using a Raspberry Pi and RTL-SDR to listen to ADS-B broadcasts from aircraft. These broadcasts contain the live current location and altitude of all aircraft in his area. When a landing aircraft is detected to be passing near his house, the Raspberry Pi sends a signal to another Raspberry Pi connected to a camera on his balcony, and that snaps a photo of the passing aircraft.
In terms of software, Arun uses dump1090 as the ADS-B decoder. For communications between the two Raspberry Pi's he uses Node-RED and Mosquitto in order to communicate with MQTT. On the second Raspberry Pi, gPhoto2 captures images from the camera, and then ImageMagick is used to write some text about the aircraft and photo on the image. Arun's post goes in further detail about the code and conditions he uses to determine when a photo should be snapped.
In the past we've posted about a similar project where an RTL-SDR and Raspberry Pi based ADS-B tracker was used with a servo mounted video camera to track and record video of passing aircraft.
SDR-Kits.net have begun selling low cost GPS antennas that are modified to receive the Inmarsat satellite frequencies between 1535 MHz to 1550 MHz. They also have a version for Iridium satellites that receives 1610 MHz to 1630 MHz. The antennas are powered by a 3-5V bias tee, so they should work fine with SDRplay, Airspy and RTL-SDR Blog V3 units.
Mike Ladd from SDRplay has recently sent us a guide to receiving AERO and STD-C messages on L-band with the SDR-Kits antenna and an SDRPlay unit running SDRUno (Megaupload link).
AERO messages are a form of satellite ACARS, and typically contain short messages from aircraft. It is also possible to receive AERO audio calls. STD-C aka FleetNET and SafetyNET is a marine service that broadcasts messages that typically contain text information such as search and rescue (SAR) and coast guard messages as well as news, weather and incident reports. Some private messages are also seen. To decode AERO Mike uses JAERO, and for STD-C he uses the Tekmanoid STD-C decoder.
Mike has also created a very handy bank of frequencies for the SDRUno frequency manager which can be downloaded from here.
We note that if you're interested in waiting, at the end of September we will have an L-band patch antenna set available too. Our antenna will work from 1525 up to 1637 MHz. Prototypes have shown have shown good Inmarsat, Iridium and GPS reception. More details coming next month when manufacturing gets closer to finishing up.
Over on GitHub user mcogoni (Marco/IS0KYB) has recently released a new program called Pepyscope. Pepyscope is a simple and fast panadapter application that is designed to be used with direct sampling capable RTL-SDR's such as our RTL-SDR Blog V3 units. Like other panadapters you simply connect the IF output from the hardware HF radio into the input of the RTL-SDR. Then Pepyscope gives you a waterfall display that helps users to easily visualize the spectrum.
Pepyscope is open source and runs on Linux PCs. So far Marco has tested Pepyscope with a KENWOOD TS-180S (single conversion with IF at 8.83 MHz) and an RTL-SDR v3. He has also uploaded a demonstration video on YouTube.
On this weeks episode of SignalsEverywhere, host Corrosive tests out our KerberosSDR coherent RTL-SDR unit for radio direction finding. If you didn't already know KerberosSDR is our experimental 4x Coherent RTL-SDR product. With it, coherent applications like radio direction finding (RDF) and passive radar are possible. Together with the KerberosSDR direction finding Android app it is possible to visualize the direction finding data produced by a KerberosSDR running on a Pi3/Tinkerboard.
In the video Corrosive uses the KerberosSDR together with the recently updated companion Android app to determine the location of a P25 control channel. By driving around with the app constantly collecting data he's able to pinpoint the location within about 15 minutes.
If this interests you, we also have some more driving demo videos available here.
In addition to his video, Corrosive has also created a very useful calculator that can be used to calculate the required antenna spacing for a circular or linear direction finding array that can be used with the KerberosSDR.
Thank you to Christian, programmer of the AIS Share Android App for letting us know about some updates to his AIS Share Android application. AIS Share is a €2 app for Android that allows you to turn an Android device into an AIS receiver together with an RTL-SDR. AIS stands for Automatic Identification System and is used by ships to broadcast their GPS locations in order to help avoid collisions and aide with rescues. An RTL-SDR with the right software can be used to receive and decode these signals, and plot ship positions on a map.
Recent updates to AIS Share have brought improved AIS reception, and updates allowing it to run on the latest Android version. A new video demonstrating the software was also uploaded to YouTube.
The App has also been featured in the February 2019 edition the "Practical Boat Owner" magazine (paid magazine with digital editions). The article discusses using AIS Share and an RTL-SDR to stream data to Boat Beacon, which is a popular chart navigation app. A similar but free tutorial on setting up AIS Share and Boat Beacon can be found here.