Jenny List writes about how an undocumented feature in certain ESP32 chips allows the raw I/Q stream to be tapped before the WiFi modem, effectively turning them into software-defined radio receivers. Discovered independently by Espargos and a Reddit user, the mode supports both 2.4 and 5 GHz bands but is limited to receive-only operation.
- Only works on ESP32 variants with earlier Tensilica hardware; Bluetooth-only and non-radio P4 chips won't work
- Transmit capability appears possible but remains undocumented, with the discoverer refusing to share due to "rule 3"
- The 80 Msps 32-bit/sample data rate creates bandwidth challenges for external transfer via SDIO or UART interfaces
- Only works on ESP32 variants with earlier Tensilica hardware; Bluetooth-only and non-radio P4 chips won't work
- Transmit capability appears possible but remains undocumented, with the discoverer refusing to share due to "rule 3"
- The 80 Msps 32-bit/sample data rate creates bandwidth challenges for external transfer via SDIO or UART interfaces
Gregory Gibson writes about applying the Linux kernel's tool-generated content guidance to his vibe-coded Morse decoder app, CW Inspector. He used OpenAI Codex to build the app, then subjected it to the kernel's five transparency rules: name the tool, preserve inputs, keep the prompt trail, record exactly what the tool changed, and make the generated code prove itself. The process exposed a critical flaw — the decoder confidently produced a wrong answer (reading TTT E as SE) with zero errors, demonstrating that a clean run doesn't guarantee correctness.
- The original algorithm treated the shortest 55% of keyed pulses as dots, which broke on dash-heavy messages; the fix looks for a large ratio between short and long pulse clusters before recording dot duration.
- The author deliberately withheld the actual WAV file from Codex, providing only metadata and the expected message, to create an independent acceptance test rather than letting the model optimize against the exact sample it would later decode.
- The kernel's guidance applies only when a tool generates something substantial (functions, files, fixes, translations), not for spelling corrections, autocomplete, or variable renames.
- The original algorithm treated the shortest 55% of keyed pulses as dots, which broke on dash-heavy messages; the fix looks for a large ratio between short and long pulse clusters before recording dot duration.
- The author deliberately withheld the actual WAV file from Codex, providing only metadata and the expected message, to create an independent acceptance test rather than letting the model optimize against the exact sample it would later decode.
- The kernel's guidance applies only when a tool generates something substantial (functions, files, fixes, translations), not for spelling corrections, autocomplete, or variable renames.
Colorado Mesh provides recommended Meshtastic configuration settings for community members, covering LoRa, channel, device, position, MQTT, and telemetry parameters. The network has pivoted from the default LongFast preset to MediumFast following sustained growth, and operates alongside a separate MeshCore network.
- Hop limit starts at 3 and should be increased incrementally to 5, 6, then 7 if messages are acknowledged but not replied to; if 7 fails there is likely no path.
- MQTT is disabled by default but available for members in areas of bad reception, using root topic msh/US/CO/.
- Device role must be set to Client, not Router or Router Late.
- Position broadcast interval is thirty minutes with smart mode enabled and a 100m minimum distance threshold.
- Hop limit starts at 3 and should be increased incrementally to 5, 6, then 7 if messages are acknowledged but not replied to; if 7 fails there is likely no path.
- MQTT is disabled by default but available for members in areas of bad reception, using root topic msh/US/CO/.
- Device role must be set to Client, not Router or Router Late.
- Position broadcast interval is thirty minutes with smart mode enabled and a 100m minimum distance threshold.
Erik Elfstrom writes about OrcSDR, an open-source standalone SDR application designed for the M5Stack Tab5 / ESP32-P4 and compatible with the RTL-SDR Blog V4. Unlike traditional setups that require a PC or Raspberry Pi to act as a host, OrcSDR allows the microcontroller itself to handle radio functions, DSP, graphics, audio, storage, and the touchscreen interface. This creates an efficient, low-power, and self-contained portable radio appliance capable of single-channel decoding for various modes such as FM, ADS-B, P25, LoRa, and more.
- The ESP32-P4 handles USB host communication with the RTL-SDR Blog V4 directly.
- Dedicated screens are available for FM, P25, ADS-B, LoRa, RF analysis, and 2.4 GHz Wi-Fi analysis.
- Includes advanced visualization features like I/Q constellation, phosphor persistence, and a 3D spectrum history.
- Features a serial command interface allowing control via scripts or automation in addition to the touchscreen.
- The underlying driver was developed by analyzing USB traffic from known desktop software using Wireshark.
- The ESP32-P4 handles USB host communication with the RTL-SDR Blog V4 directly.
- Dedicated screens are available for FM, P25, ADS-B, LoRa, RF analysis, and 2.4 GHz Wi-Fi analysis.
- Includes advanced visualization features like I/Q constellation, phosphor persistence, and a 3D spectrum history.
- Features a serial command interface allowing control via scripts or automation in addition to the touchscreen.
- The underlying driver was developed by analyzing USB traffic from known desktop software using Wireshark.
The SuperBase is a $75 standalone Meshtastic device from muzi works, combining a Base Uno and Super IO board inside a 3D-printed translucent PETG case. It offers built-in GPS (dual GPS/BDS), a digital compass, a large square OLED screen, and a 1500mAh battery that lasts up to 2 days with GPS enabled. Available pre-assembled or as a DIY kit requiring soldering.
- Powered by the nRF52840 SoC and SX1262 radio, supporting both 868MHz and 915MHz via a universal stubby antenna
- Weighs 80.3g (2.8oz) with antenna; dimensions roughly 48 x 80 x 19mm
- Features a 2-mode power switch, tone buzzer for notifications, fast USB-C charging up to 1A, and onboard RTC
- Customer reviews (4.55/5 from 11 reviews) praise portability and ease of use but note the translucent case chips easily and the display shows horizontal line shadowing at max brightness
- Powered by the nRF52840 SoC and SX1262 radio, supporting both 868MHz and 915MHz via a universal stubby antenna
- Weighs 80.3g (2.8oz) with antenna; dimensions roughly 48 x 80 x 19mm
- Features a 2-mode power switch, tone buzzer for notifications, fast USB-C charging up to 1A, and onboard RTC
- Customer reviews (4.55/5 from 11 reviews) praise portability and ease of use but note the translucent case chips easily and the display shows horizontal line shadowing at max brightness
Ground Station is an open-source, browser-based application for tracking satellites and celestial targets, controlling station hardware, and receiving, decoding, and recording SDR signals. Built for amateur radio operators, satellite enthusiasts, and researchers, it brings orbit visualization, multi-target tracking consoles, SDR waterfall analysis, packet and telemetry decoding, scheduled observations, and hardware management into a single web interface.
- Supports RTL-SDR, SoapySDR, UHD/USRP and virtual SigMF playback SDR
- Automated observations scheduled via APScheduler for AOS/LOS pass recording with rotator and Doppler rig control
- Frontend uses React, Redux Toolkit and Material-UI; backend uses FastAPI, Skyfield/SGP4 and Socket.IO
- Supports RTL-SDR, SoapySDR, UHD/USRP and virtual SigMF playback SDR
- Automated observations scheduled via APScheduler for AOS/LOS pass recording with rotator and Doppler rig control
- Frontend uses React, Redux Toolkit and Material-UI; backend uses FastAPI, Skyfield/SGP4 and Socket.IO
Al Williams writes that International Reply Coupons (IRCs) are nearing their end as the Universal Postal Union prepares to phase them out by December 31, 2026. Once essential for radio hobbyists and international mailers, these coupons allowed individuals to pay postage in one country that could be exchanged for local stamps in another, but modern digital communication has rendered such physical vouchers nearly obsolete.
- Radio enthusiasts used the system primarily to receive QSL cards from foreign stations without requiring senders to cover international shipping costs.
- The Universal Postal Union consists of an association of post offices across 192 countries.
- Charles Ponzi's original scheme involved exploiting price discrepancies for these coupons between different nations.
- Radio enthusiasts used the system primarily to receive QSL cards from foreign stations without requiring senders to cover international shipping costs.
- The Universal Postal Union consists of an association of post offices across 192 countries.
- Charles Ponzi's original scheme involved exploiting price discrepancies for these coupons between different nations.
An exploration of the history and eventual decline of Heathkit, a company famous for producing comprehensive electronic kits ranging from ham radio to early personal computers. Starting with military surplus in 1947, the brand became known for its high-quality components and educational manuals that helped users truly understand their builds. The article discusses how market shifts toward inexpensive pre-assembled electronics and the acquisition by Zenith led to the company's eventual closure in 2012.
The Leo Bodnar Electronics online shop provides a specialized range of electronic components and hardware for professional and enthusiast use. The catalog includes precision frequency references such as GPSDO modules for ham radio and aerospace applications,, NTP servers
An ADS-B decoder described as a swiss knife for decoding aircraft data. This project is a fork of Mictronics' readsb and supports various Software Defined Radio devices such as RTL-SDR, HackRF, Bladerf, and PlutoSDR. It offers robust networking options including Beast/SBS protocols and JSON output, making it an ideal backend for global flight tracking systems like tar1090.
Main topics:
ADS-B decoding via SDR hardware
Extensive network connectivity support (Beast, SBS, JSON)
Integration with mapping tools like tar1090
Support for multiple SDR device types
Main topics:
ADS-B decoding via SDR hardware
Extensive network connectivity support (Beast, SBS, JSON)
Integration with mapping tools like tar1090
Support for multiple SDR device types
