TechMinds: How to Track Weather Balloons Using SDR

In his latest video Tech Minds has uploaded a video showing how to use an SDR to receive transmissions from radiosondes carried by weather balloons. Every day meteorological agencies around the world launch weather balloons several times a day. Each balloon carries a device called a radiosonde which continuously transmits weather telemetry to a ground station. With an SDR, antenna and free software it's possible to decode these radiosonde signals yourself from home.

In the video Tech Minds uses an RSPdx, SDRuno, VBCable and the RS41 Tracker software to receive telemetry from an RS-41 radiosonde launched in his area. We note that an RTL-SDR and SDR# could also be used. He shows the various bits of weather information available from the telemetry including information like temperature, pressure, humidity and the dew point. GPS and hardware status data is also available. Finally he shows how to view the balloon's flight path in Google Earth.

How To Track Weather Balloons Using SDR

Metal Case Upgrade for the SDRplay RSP1A back in Stock

Our metal case upgrade kit for the SDRplay RSP1A software defined radio is now back in stock in our store and will be ready to ship out within the next couple of days. This is a premium aluminum metal upgrade enclosure for the SDRplay RSP1A. Helps block RF interference and protects the RSP inside the sturdy enclosure. This will be the final batch made of this product, so if you are interested please order before stock runs out for good.

The kit includes 1x black aluminum metal enclosure with two labelled side panels, 1x black semi-hardshell carry case, 1x thermal pad to keep the RSP1A cool and mechanically stable inside the enclosure, 1x accessory set including enclosure screws, GND lug bolt set and 3M anti-slip rubber feet.

RSP1A Metal Case Upgrade
RSP1A Metal Case Upgrade

NanoVNA V2 Video Tutorials

The NanoVNA V2 (aka S-A-A-2) is a vector network analyzer (VNA) with 50 kHz to 3 GHz frequency range. Recently is has become readily available for around $60 + shipping from the Tindie store. We like this product a lot and are planning to get some for our store soon as well. (Update: A limited quantity of NanoVNA V2's are now available in our store)

A Vector Network Analyzer (VNA) is an extremely useful tool for radio hobbyists as it allows you to measure and tune antennas and filters, as well as measure cable loss among other applications. Until recently low cost VNA's cost hundreds of dollars. Then came along the original NanoVNA which brought expensive VNA capabilities to the masses with its low $40 pricing. But the original design is limited to a maximum frequency of only 900 MHz. The new V2 design pushes this maximum frequency up to 3 GHz officially, and unofficially up to 4.4 GHz with reduced performance. It also improves on overall dynamic range and maintains the affordable sub $100 price. We note that the NanoVNA V2 is unrelated to the original NanoVNA apart from being the inspiration, and sharing the same firmware base.

Over on YouTube Robert J. Meade has been uploading a series of videos demonstrating and teaching viewers how to use the NanoVNA V2 to measure various devices. For example in his videos he shows how to use the NanoVNA V2 to measure one of our RTL-SDR Blog Broadcast FM filters, how to measure a log spiral & clover antenna, use measurements to rebuild a variable attenuator, measure an active device (SAWbird+ NOAA), and how to measure a DIY microstrip L-band LNA. If you're just getting started with the NanoVNA V2, then these are some great videos to start with.

NanoVNA V2: RTL-SDR.com FM Bandstop Filter Measurements via NanoVNA-QT

Hak5: Turning a Key Croc into an RTL-SDR Server

The Hak5 Key Croc is a pentesting tool designed for emulating USB devices such as keyboards. It is commonly used by pentesters for keylogging and keystroke injection. It has some advanced features like keyword detection which can be used to detect when a certain word is typed. Under the hood it runs Linux on a quad-core ARM processor.

Over on the Hak5 YouTube channel Glytch shows us that he's been using the Key Croc as a remote RTL-SDR server. The server is setup through a payload script, which is then activated by typing "setup" into notepad on a PC. The keystroke logging and keyword detection feature detects the setup keyword, and runs the payload script which installs the RTL-SDR drivers and rtl_tcp server all while using the keystroke injection feature to output the install progress. Then it is a simple matter of plugging in an RTL-SDR, and connecting to the rtl_tcp server on a program like SDR#. 

Glytch notes that this is useful because you can run the entire Key Croc server and RTL-SDR on a portable battery pack, and now you have a remote SDR that you can place anywhere within your WiFi network.

Turning a KeyCroc into an RTL SDR Server w/ Glytch

DragonOS: Decoding Iridium Satellites with the Iridium Toolkit and an RTL-SDR

DragonOS is a ready to use Linux OS image that includes various SDR programs preinstalled and ready to use. The creator Aaron also runs a YouTube channel that has multiple tutorial videos demonstrating software built into DragonOS.

In his latest video Aaron explores Iridium reception with an RTL-SDR Blog V3, RTL-SDR Blog Active L-Band Patch Antenna and Iridium Toolkit/gr-iridium. Iridium is a satellite constellation that provides services such as global paging, satellite phones, tracking and fleet management services, as well as services for emergency, aircraft, maritime and covert operations too.

In the video he shows how to edit the config file to turn the bias tee on, how to record Iridium data, how to install the AMBE voice decoder, and finally how to decode the Iridum data with Iridium toolkit and play voice recordings.

DragonOS LTS Decoding Iridium satellites with the Iridium toolkit (gr-iridium, RTL-SDR)

Tech Minds: Testing the Mayhem Firmware on the HackRF Portapack

In a video uploaded to YouTube last week, Tech Minds explored the HackRF Portapack, which is an add on for the HackRF SDR that allows the HackRF to be used portably without a PC. In that video he demonstrated it running the stock firmware.

In his latest video Tech Minds explores the Mayhem firmware, which is firmware developed by a third party in order to add significantly more features. The Mayhem firmware is a fork of the Havok firmware which is no longer maintained. If you're interested, back in 2018 we did our own review of the Havok firmware.

In the video Tech Minds first explains how to install the Mayhem firmware which also requires you to add an external SD card into your portapack. He goes on to demonstrate the various RX decoders available including ADS-B, ACARS, AIS, AFSK, BTLE, FM/AM/SSB audio, analog TV, ERT meters, POCSAG, Radiosonde and TPMS. Next he shows the various transmittable signals available including, ADS-B, APRS, BHT, GPS Sim, Jammer, Key Fob, LGE, Mic, Morse, Burger Pagers, OOK, POCSAG, RDS, Sounds, SSTV, TEDI/LCR and TouchTune.

MAYHEM Firmware for the HackRF Portapack Installation / Overview

DSD (Open Source) with dPMR Decoding and Windows Binaries Released

Digital Speech Decoder (DSD) is an open source program for decoding signals containing digital speech, such as DMR and P25. The open source version has been mostly surpassed in use over the last few years by the closed source DSD+ version. However, work is still ongoing on the open source version, and a recent fork by Louis-Erig HERVE @LouisErigHerve has added support for Digital Private Mobile Radio (dPMR) decoding.

dPMR is an open, non-proprietary trunked radio standard that supports both data and digital voice transmission. A licence free variation for short range communications called dPMR466 uses the 446.1–446.2 MHz band. Other modes allow for efficient peer to peer to peer operation (mode 1), operation with a base station repeater (mode 2), or with a trunking signal (mode 3).  All dPMR signals operate in FDMA mode with an efficient bandwidth of only 6.25 kHz. dPMR is also known as Icom IDAS and Kenwood NEXEDGE.

Code for Louis-Erig's DSD fork can be found on his GitHub, and he has also released binaries for Windows on his website. Over on his Twitter he has also been mentioning that he has been able to get around the basic privacy modes on DMR.

dPMR radios, data stations and repeater hardware.
dPMR radios, data stations and repeater hardware.

DragonOS: DSP and Signal Analysis with Composable-SDR, Inspectrum and an RTL-SDR

DragonOS is a ready to use Linux OS image that includes various SDR programs preinstalled. The creator Aaron also runs a YouTube channel that contains multiple tutorial videos for DragonOS

One of the latest videos shows us how to use composable-sdr and Inspectrum to capture and analyze signals. Both programs are pre-built into the latest version of DragonOS. Composable-sdr is a set of DSP processing blocks for SDRs embedded in Haskell. One thing it does well is allowing users to easily capture and record demodulated signals for later use via the terminal. Inspectrum is a tool for analysing and reverse engineering signals that have been recorded.

In the video Aaron explores many of the composable-sdr examples discussed on it's GitHub readme page. Including analyzing a wav file recorded with Composable-sdr with Inspectrum and demodulating and recording a wideband FM signal. He also mentions how it's possible to create a PMR446 scanner that records up to 16 channels at once, and how decode helicopter FSK data from audio heard on YouTube (which we mentioned in a previous post).

DragonOS LTS DSP and signal analysis with Composable-SDR + Inspectrum (RTL-SDR)