Thank you to BG7BAG for writing in and sharing a free user guide for SDRconnect, SDRplay's multi-platform software for their RSP series of SDRs, which we've covered several times before. SDRplay only provides a "Quick Start" guide and a few application notes for SDRconnect, so BG7BAG wrote a full manual from scratch, based on daily use with an RSPdx-R2.
The guide is written side by side in English and Chinese, with a shared glossary of SDRconnect's interface terms, so it may be most useful to Chinese-speaking SDRplay users, for whom there is no official manual. It is based on SDRconnect V1.0.10 and includes a quick start section, a 22-chapter manual covering topics like remote operation, troubleshooting and PPM calibration, and an advanced guide on HDR mode, notch filtering, IQ recording and scheduling.
BG7BAG also shared his HAM Radio Atlas, a free map of over 12,000 amateur radio repeaters on the 2m, 1.25m and 70cm bands, searchable by location, callsign and band. Repeater data currently covers the USA (26 states), Australia, China, Austria and New Zealand, with a province-by-province list for mainland China.
A screenshot of one part of the manual.
AI Disclaimer: We note that this guide appears to have been written with the help of AI.
Thank you to Rafał for writing in and sharing his open-source project FalconSDR, a free scanning and recording program he's been working on over the last few months. Rafał notes that after getting into RTL-SDR listening, he found that popular SDR programs didn't have the scanning and recording features he wanted.
FalconSDR can scan multiple bands or channels, even when they are far apart, with separate settings for each band and a blacklist for skipping birdies and unwanted channels. A "recency boost" feature sends the scanner back to channels with recent activity, and it can record multiple transmissions at once. Recordings go into a searchable library and can optionally be transcribed to text with Whisper. In hybrid mode, a server handles recording and a PC handles transcription.
The interface runs in a browser, either locally or on a headless server, so you can reach it from a PC or phone on your network. RTL-SDRs are supported natively, and Rafał has tested the program for months with an RTL-SDR Blog V4. Other SDRs work via SoapySDR. Linux and Windows 11 have been tested, but the macOS builds are marked as experimental. The code is open source under GPLv3 and available on GitHub.
FalconSDR Screenshots
AI Disclaimer: While the author does not disclose it, the repository includes an AGENTS.md file described as "Guidance for AI coding agents working in this repository", so it is our opinion that this software may be coded with the help of AI.
Back in September, we posted about OrcSDR, open-source firmware that runs an RTL-SDR directly on the ESP32-P4 microcontroller-based M5Stack Tab5 tablet, with no PC or Raspberry Pi needed. Erik Elfstrom has now written in again to share that OrcSDR v0.5.0-beta.1 (release notes) is out, with several new features and a lot of stability work.
The main additions are SSTV reception and a dedicated ACARS dashboard. SSTV images are drawn directly on the touchscreen and saved to the SD card, and the ACARS dashboard shows live messages and aircraft lists. Erik has tested SSTV with Robot36, PD120, and Scottie S1 on various RTL-SDR models. Offline maps have also been added to the LoRa/Meshtastic, ADS-B, and FT8 dashboards. There is also a new 'Dead Air' dashboard for logging RF and audio activity, and Erik notes that despite the Halloween timing, it is not a ghost detector.
Erik also notes that a lot of work has gone into fixing layout issues, redraw flicker and memory pressure, and there is now a guided first-run setup. The software is still in beta, and Erik says that not every issue is gone yet. The update can be installed with M5Burner or the browser installer, and the code is open source under AGPL-3.0 and available on GitHub.
Some screenshots of new OrcSDR Features
AI Disclaimer: The OrcSDR README notes that the project was created with "extensive AI assistance".
Thank you to the OrbitNight team for writing in and sharing their "OrbitNight satellite radar", a free browser-based pass viewer for any satellite in the catalog. It can also point an antenna rotator straight from the browser over USB using Web Serial, so you don't need to install anything.
The radar page shows a polar plot of the pass track, live azimuth and elevation readouts, and an AOS/LOS countdown. A radio tab lists downlink and uplink frequencies taken from SatNOGS. For rotator control, it supports Yaesu GS-232 compatible controllers (including K3NG and ERC) and EasyComm II controllers like those used on SatNOGS stations connected over USB serial, or Bluetooth on Android. It also has an azimuth offset setting and a 1 degree deadband.
The site works in Chrome and Edge on desktop, and rotator control needs a browser that supports Web Serial. It's free and needs no sign-up. The team notes that there is no 450 degree or flip mode yet, and they'd like to hear from anyone who tries it with a real rotator. If you track LEO satellites with a directional antenna and an RTL-SDR, this could be a simpler option than setting up Gpredict and Hamlib. We note, however, that we couldn't find an open-source codebase.
Earlier this month we posted about sdrtop, a Rust-based SDR bench instrument that runs in a terminal and is aimed at measurement rather than listening. Viktor László (MusiThang on GitHub) has now written in again to share several updates. Viktor notes that the goal is still to "make radio signals and the measurements behind them inspectable, rather than hiding everything behind a decoded result."
The biggest additions are new Wi-Fi tools. sdrtop can now survey 2.4 GHz channels 1 to 13 and name the least busy one, inspect a single channel frame by frame at three time scales, and show a channel's airtime use second by second. These tools need 20 Msps, so you need an SDR like the HackRF. There is also a new POCSAG pager decoder written from the ITU standard without external libraries. Viktor tested it over the air by transmitting with a HackRF and PortaPack Mayhem and receiving with an Airspy R2.
The Airspy R2 is now natively supported too. Its gain staging follows the R2's Linearity and Sensitivity gain curves, and sdrtop warns you before the tuner clips. RTL-SDRs are still fully supported, and native support for the SDRplay RSP1B and Airspy HF+ Discovery is in progress. The code is open source under the GPLv3 and available on GitHub.
Some screens from sdrtop
AI Disclaimer: The project's CREDITS.md file notes that Claude Code was used for implementation, architecture discussion and problem-solving.
Thank you to Peter Holzhauser for writing in and sharing Muxwright, a multi-standard radio and TV test transmitter for the ADALM-Pluto (PlutoSDR). Peter has in the past submitted his ESPSoup, and Etherbulb projects. Muxwright is intended for home lab testing only, with the Pluto connected to the receiver under test via cable and attenuator or inside a shielded box, as radiating broadcast standards over the air requires a frequency assignment.
Muxwright can generate FM stereo with RDS/RBDS, DAB+, DVB-T, DVB-T2, DVB-C, DVB-S/S2, ATSC 1.0, ISDB-T, DTMB and analog PAL/NTSC TV, plus DVB-S2 DATV for QO-100 and other amateur bands (which of course requires an amateur radio license). The digital TV modulators run directly on the Pluto and everything is controlled from a browser dashboard. The Pluto's RX input can also be used as a monitoring receiver for expected vs. actual test reports.
The software runs on Windows 10/11 via WSL2 and is currently at Beta 0.4. The README notes that it has only been verified on the original Pluto Rev. B, and that DVB-T2, ATSC, ISDB-T and DTMB are still untested with real TV sets. The code is MIT licensed (with the FM/RDS module under GPL-3.0) and available on GitHub, however, the Windows installer is only available by request via email from the website.
Muxwright Transmitting DVB-T with a PlutoSDR
AI Disclaimer: The project's GitHub commit history lists Claude as a co-author.
Thank you to Logan Zarov for writing in and sharing D325f-SDR, a project that turns the cellular modem in an old LG D325 (L70 Dual) Android phone into a software-defined radio. This is another in a series of wireless devices being reverse-engineered into SDRs with the help of AI. Recently we've seen the ESP-SDR, W1700K-SDR, BirrariaSDR, and LR2021 LoRa-SDR projects. From now on, we're calling these newly discovered SDRs "Sleeper SDRs": commodity RF devices with hidden SDR capabilities that have been discovered and tapped.
To activate D325f-SDR mode, the phone needs to be rooted and running LineageOS 14.1 with TWRP and a custom kernel. A small patch is then applied to the Hexagon firmware on the phone's Qualcomm MSM8610 modem, which enables the ability to stream raw 8-bit IQ samples at 7.68 MS/s (about 5 MHz of bandwidth) into a shared memory buffer that the custom kernel sets up. An Android app based on Dennis Mantz's RF Analyzer then shows the spectrum and waterfall and demodulates AM, FM, SSB, and CW on the phone itself.
Tuning works by hooking into the modem's stock PLL calculation. Logan has confirmed PLL lock from 1.7 to 2.17 GHz and has received an 1875 MHz cellular base station downlink directly. To get below 800 MHz, the app uses an interesting trick. It keys the phone's own Bluetooth transmitter to produce a carrier in the 2.4 GHz ISM band, and uses that carrier as a mixer. In this mode, Logan has received FM broadcast stations, an analog TV carrier at 551.25 MHz, and shortwave AM stations between 8 and 15 MHz, including speech at 14.970 MHz.
For the hardware modification, the B8 and B1 RF bypass wires are brought out to the phone's 3.5 mm headphone jack, and an antenna plugs in through a homemade SMA-to-3.5 mm adapter.
Logan is upfront about the limitations. So far it has only been built and tested on one phone, and calibrated sensitivity figures haven't been published yet. The modem-side buffer is only about 8 ms long, so a busy CPU can stop the stream. The Bluetooth carrier coupling technique also hasn't been characterized. We also note that the phone actively transmits a Bluetooth carrier in the below-800 MHz mode, which probably violates the Bluetooth module's certification and could make this mode legally grey.
Earlier this month we posted about the Russian Elektro-L3 geostationary weather satellite drifting west from 76°E to 14.5°W. It is replacing Elektro-L2 and could bring unencrypted L-band LRIT and HRIT imagery back to Western Europe. Now tec_msat has written in again to let us know that Elektro-L3 has arrived. It is already transmitting X-band RDAS and testing LRIT and HRIT.
tec_msat notes that the satellite was only active on C-band for a couple of days. Then, on October 26, its RDAS, xRIT, and DCP (Data Collection Platform) downlinks all went up. Elektro-L2's DCP transmission at 1697 MHz was switched off at 06:30 UTC, and L3's DCP came up at 07:02 UTC. LRIT data was being received from about 09:42 UTC. GGAK (space weather data) is still being transmitted from Elektro-L2 for now.
This is the first xRIT from 14.5°W in years, so tec_msat warns that transmissions may be sporadic for a while. It's too early to judge signal strength, but it already looks stronger than L3 did at low elevation (under 15 degrees) in its old slot.
If you're in Western Europe, now is a good time to get your dish ready. SatDump is the best software for reception and decoding, and our Discovery Dish with L-band feed and an RTL-SDR Blog V3 is a great starting point for hardware.
Elektro-L3 LRIT Image Received from 14.5°W on October 26
