Category: Applications

Frugal Radio: Review of our RTL-SDR Blog L-Band Patch Antenna

Over on YouTube Rob from Frugal Radio has uploaded a video reviewing our new L-Band Patch antenna which we released for sale late last month. The patch is currently on a release sale for US$44.95 including free standard airmail shipping to most countries. We will be ending the sale this Wednesday at which point the price will go to US$49.95, still with free standard airmail shipping to most countries. The patch can be purchased from our web store at www.rtl-sdr.com/store.

In the video Rob demonstrates the patch receiving Inmarsat signals strongly, and decodes a few AERO signals using JAERO. He shows that the patch works on any RTL-SDR with bias tee capability as well as an Airspy Mini. Lastly he compares the unit against the SDR-Kits patch.

We note that we are also supplying a kit for a giveaway to Frugal Radio subscribers that we will announce in an upcoming video coming out a few days time.

RTL-SDR updated L-band patch antenna review - perfect for your SDR radio!

UPDATE: Giveaway information now available in the latest video below.

RTL-SDR L-Band Patch Antenna Giveaway

Tech Minds: Using BaseStation Software with any ADSB Hardware + XRange2 Demonstration

BaseStation is an old ADS-B visualization program that was originally made to be used with BaseStation SBS receivers which were commonly used for ADS-B reception before the discovery of the RTL-SDR. Many old time ADS-B enthusiasts may already be set up with this software and would like to continue using it, however may have a dead SBS unit, or simply want to use a more modern receiver.

In his latest video Tech Minds demonstrates how you can use the ModeSMixer software to translate ADS-B data coming from an RTL-SDR compatible program like dump1090 into the BaseStation data format.

How To Use BaseStation With ANY ADSB Hardware - Software ModeSMixer

Tech Minds has also released an earlier video demonstrating the AirNav RadarBox XRange2. This appears to be essentially an ADS-B optimized RTL-SDR and Raspberry Pi in a plastic box, with custom SD Card set up and ready to go. At a price of US$299 it is quite an expensive premium to pay, but it may be of use to aviation enthusiasts who have poor technical computer skills that still want to set up a home aircraft tracking station.

Airnav Radarbox XRANGE 2 - Enhanced ADSB Standalone Receiver

Vector Measurements with an RTL-SDR and HackRF Based System

Over the course of 2020 Tomaž Šolc from Avian's Blog has been slowly working on an RTL-SDR based vector network analyzer system. The system currently consists of an ERASync Micro signal generator, a custom time multiplexing board, an RF bridge, an RTL-SDR with E4000 tuner and some custom software.

A vector network analyzer allows the measurement of antenna or coax parameters such as SWR, impedance, phase and loss. It can also be used to characterize and tune filters. In his last post Tomaž copmares his RTL-SDR based system with a NanoVNA-H and shows similar results, confirming that the system is working.

Recently he's also swapped out the RTL-SDR for a HackRF which allows him to make measurements up to 6 GHz. Although he notes that the dynamic range quickly degrades after 3.5 GHz presumably due to connector and phase noise issues.

The entire post chain is a good read to see how he ended up designing the system, and we link to each post below for easier reading:

Homemade Vector Network Analyzer with ERASynth Micro, HackRF, RF Bridge, Custom Time Multiplexor

Frugal Radio: Monitoring En Route Air Traffic Control, Oceanic Clearances, and Company Frequencies

Rob from Frugal Radio has recently uploaded part three in his airband monitoring series. The the last video Rob discussed what communications can be received from the airport. In this weeks video Rob explains how air traffic control is handled over large areas, and also shows examples of what you might hear when an aircraft communicates with it's parent company.

Air Traffic Control Centres provide ATC coverage across most of the globe. This video gives an overview of how you can listen to pilots and Air Traffic Controllers as along their routes.

This video talks about the en route Air Traffic Control systems in the USA (ARTCC managed by the FAA), UK (managed by NATS) and Canada (managed by Nav Canada).

Company frequencies are also covered in this video, along with examples of conversations received at my location in the last few days.

Monitoring En Route Air Traffic Control, Oceanic Clearances, and Company Frequencies

NOAA-2 Returns from the Dead

Satellites can stay in orbit for years after their decommissioning date. Although they are turned off, often after many years they can turn on again as the battery chemicals begin to break down, eventually allowing electricity directly to the satellite systems whenever the solar panels are in light. We've seen this phenomenon occur with various decommissioned satellites.

Recently it was discovered by amateur radio satellite watcher Scott Tilley that NOAA-2 appears to be actively transmitting again in the L-band at 1697.5 MHz. NOAA-2 is a weather image satellite that was operational from 1972 - 1975.

Next over on his blog Derek OK9SGC was able to confirm reception of the signal, make a recording, and then with the help of @Xerbo10 discovered that you can actually receive an image from it. However as is to be expected the camera is not actually operational and all you get is a few grey lines indicating voltage calibration and sync telemetry.

It's unknown how long the satellite will stay undead, but if you manage to receive it let us know in the comments.

NOAA-2 Revival Signal and APT Image

SDR# Updated: Improved Performance and Better RTL-SDR Compatibility

SDR# (SDRSharp) is one of the most popular free software defined radio programs available with RTL-SDR support. Recently it has been updated to version 1811 and the new version brings improved performance and also improves RTL-SDR compatibility with some systems. The changelog reads:

Date:   Mon Mar 29 15:03:09 2021 +0200
Commit: d5cb6c3

More DSP optimizations;
Many fixes for RTL dongles (mainly workraounds for old libs);
Revert to libusb 1.0.20.11004 for backward compatibility;
Revert to portaudio 2016 for backward compatibility;
Code cleanup.

@lambdaprog (the SDR# programmer) has also tweeted showing how well SDR# can run on a 10 year old i7 4700 laptop with the new performance improvements. With a huge 160 MSPS baseband IQ file, the software is seen to be using very minimal CPU. 

Building a GOES-16 Antenna out of Trash, Cardboard and Foil Tape

Over on his YouTube channel saveitforparts has uploaded a video showing how he was able to modify and old DirectTV satellite dish found in the dumpster with cardboard and foil in order to receive images from the GOES-16 geostationary weather satellite.

I wanted to download images from the GOES-16 weather satellite, but didn't have a big enough satellite dish. So I made one out of an old TV dish, cardboard, and aluminum tape! Amazingly this actually works, and I was able to pull live pictures of the earth off the satellite in geostationary orbit! The cardboard won't last long-term, so I'm looking for an antique C-band dish that I can set up as a more permanent solution. However, for a cheap and expedient ground station, this worked pretty well!

Satellite Ground Station With Trash, Cardboard, and Foil Tape!

SMOG-1 PocketQube Satellite Successfully Launched and in Orbit

Thank you to Zoltan Doczi (HA7DCD) for submitting news about the successful launch and first reception of the SMOG-1 PocketQube Satellite (which is only 5x5x5cm in size). The pre-launch press release by Tech University of Budapest is available here, and the SMOG-1 Facebook page provided additional updates.

Back in April 2020 we first heard about the launch of SMOG-P which was the first functioning 1-PocketQube satellite, and was designed to measure electromagnetic pollution (electrosmog) from space. SMOG-1 is the successor to SMOG-P and it carries a similar mission to measure electromagnetic pollution generated by human activity in space around the Earth. Interestingly it also carries a magnetically lossy material under it's solar panels which is to act as a brake, reducing the 18-25 Orbital lifespan, thus reducing space trash after the primary mission is complete.

According to the receive and decoding instructions provided by Levente Dudas, SMOG-1 can be received with a simple satellite antennas, such as a handheld Yagi, Turnstile, Dipole or quadrifilar-helix antenna. The telemetry frequency is 437.345 MHz with callsign HA5BME. For the radio an RTL-SDR connected to a Raspberry Pi can be used, and the telemetry decoding software can be found on GitLab. 

SMOG-1 can be tracked here, although Zoltan mentions that the TLEs may not yet be accurate for several more days or weeks, as was seen with the launch of SMOG-P as well. The reason is that it is difficult for the NORAD radars to see these tiny PockQube satellites which is required for TLE generation.