Telescopic antennas attached to RTL-SDR dongles tend to tip over. This mount holds them straight. The supplied .stl files match antenna diameters of 6 to 8 mm. Mounts with other diameters are easily obtained by modifying the supplied OpenSCAD file, see instructions below [on the Thingiverse page].
Over on the Tech Minds YouTube channel Matt has posted a video tutorial that shows how to build a cheap quarter wave ground plane antenna tuned for 1090 MHz. This is the frequency of ADS-B (Automatic Dependent Surveillance–Broadcast), which is a signal broadcast by aircraft that can be used to track their GPS location.
The antenna is created from an SMA chassis mount socket, one copper wire for the receiving element, and four copper wires for the ground plane. They are soldered directly onto the socket. An LNA is added to improve reception.
Make Your Own Aircraft Tracking Antenna With RTL SDR
Crowd Supply is hosting Teardown Session 38 on Thursday 3- November at Noon PST time which will feature the Discovery Dish. Join us for this livestream where I will be talking about and showing the Discovery Dish prototype.
Discovery Dish is currently being crowd funded over on Crowd Supply. It is designed to be an easy entry to the world of L-band weather satellites, hydrogen line radio astronomy, and Inmarsat reception. The Discovery Dish aims to be the start of an ecosystem of hardware designed to get users set up with satellite reception, including a planned companion light-duty antenna rotator.
Remember to click on the “Notify me” button on the YouTube link in order to be reminded about the stream!
Thank you to Mario A. Natali (I0NAA) who wrote in an wanted to share his Windows software called TotalPower which is designed for mapping the galactic Hydrogen line and works with RTL-SDR dongles.
The Hydrogen Line is an observable increase in RF power at 1420.4058 MHz which is created by Hydrogen atoms. It is most easily detected by pointing a directional antenna towards the Milky Way as there are many hydrogen atoms in our own galaxy. This effect can be used to measure the shape and other properties of our own galaxy.
Mario writes:
[TotalPower] was originally designed to measure total power of received spectrum and that, thanks to the input of many users, is now able to perform many other tasks including the 3D mapping of selected sky areas and HLine detection with the ability to estimate the speed of rotation of galaxy arms ( respect to our position )
People have had much success in receiving L-band weather satellites like GOES and polar orbiting HRPT satellites using 2.4 GHz WiFi grid dishes, even though their 1.7 GHz signals are considered out of band for the WiFi grid dish feed. While this works most of the time, reception can be sometimes weak and borderline.
António Pereira has also shared instructions for creating an antenna rotator from an ESP32, Arduino Nano, two NEMA 23 stepper motors, two stepper controllers, two 50:1 worm gearboxes, and two optical homing switches, as well as power supplies for the motors and circuits. He also shares the Arduino code that he's written.
We also note that we currently are crowd funding for our Discovery Dish, which will be a ready to use satellite dish system for L-band weather satellites, as well as Inmarsat and hydrogen line radio astronomy. Check it out on Crowd Supply.
Modified dipole feed on a 2.4 GHz WiFi grid antenna feedA DIY antenna rotator for the modified 1.7 GHz WiFi grid dish.
Previously in 2022 we posted about Watch Duty, a nonprofit organization aiming to improve access to live public safety information regarding wildfires in California. Several populated regions of California are extremely prone to wildfires, and it's important that residents get timely notifications about nearby wildfires so they can evacuate early and/or prepare their defensible spaces.
The system works by using RTL-SDRs to monitor public safety radio channels, and ADS-B aircraft positions of firefighting aircraft in order to gather information in real time about how wildfires are moving. Volunteers monitor this information and distribute anything of importance via a smart phone app to the public. Often the information is significantly more timely compared to official channels.
Recently Nick Russel, the VP of Operations at Watch Duty sent us a link to a technical overview blog post explaining how their 'Echo' remote monitoring devices work. The post describes how Echo devices consist of a Raspberry Pi and multiple RTL-SDR Blog dongles, with all the electronics being powered via Power over Ethernet (PoE). For the antenna a wideband Discone is used.
Inside the Watch Duty 'Echo'
The rest of the post explains how their voice monitoring system works, how "tone out detection" works, which are orders for engines, strike teams, and other heavy equipment, how they make use of ADS-B data and how they are able to remotely maintain and update the system.
Importantly, Watch Duty note that they rely on volunteers and donations from the community, so please consider donating via the Watch Duty app.
Watch Duty | Echo Radio Project | Fixing emergency radio dead zones
Just a quick note for those waiting to confirm that the RTL-SDR Blog V4 is now in stock at Amazon USA. We have linked both the dongle + antenna set, and dongle only listings below. For customers outside of the USA please check our international purchasing links at www.rtl-sdr.com/store.
With the demand being high, if you were waiting please order soon as the next shipment most likely won't be in until January. To learn more about the RTL-SDR Blog V4, please see our product release post.
Although this year they are not running a sale on their direct sales platform, make sure to check their direct sales pricing if you are outside the USA, as it may end up cheaper to ship directly from SDRplay in the UK.
