# Geerling Engineering

Published articles for Geerling Engineering.

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## QuadRF can spot drones and see WiFi through my wall

DevFeed: [QuadRF can spot drones and see WiFi through my wall](<https://devfeed.tech/articles/quadrf-can-spot-drones-and-see-wifi-through-my-wall-10480.md>)

Original publisher: [Read original article](<https://www.jeffgeerling.com/blog/2026/quadrf-can-spot-drones-and-see-wifi-through-my-wall/>)

Author: jeff@jeffgeerling.com (Jeff Geerling)

Published: 2026-07-10T14:00:00Z

Content type: opinion

Language: en

Sources: [Jeff Geerling](<https://devfeed.tech/sources/jeff-geerling.md>)

Topics: [Network](<https://devfeed.tech/topics/network.md>), [Security](<https://devfeed.tech/topics/security.md>), [Open Source](<https://devfeed.tech/topics/open-source.md>), [Software](<https://devfeed.tech/topics/software.md>), [Flight](<https://devfeed.tech/topics/flight.md>)

Tags: [crowd-supply](<https://devfeed.tech/tags/crowd-supply.md>), [geerling-engineering](<https://devfeed.tech/tags/geerling-engineering.md>), [network](<https://devfeed.tech/tags/network.md>), [open-source](<https://devfeed.tech/tags/open-source.md>), [quadrf](<https://devfeed.tech/tags/quadrf.md>), [raspberry-pi](<https://devfeed.tech/tags/raspberry-pi.md>), [raspberry-pi-5](<https://devfeed.tech/tags/raspberry-pi-5.md>), [rf](<https://devfeed.tech/tags/rf.md>), [sdr](<https://devfeed.tech/tags/sdr.md>), [security](<https://devfeed.tech/tags/security.md>), [testing](<https://devfeed.tech/tags/testing.md>), [ui](<https://devfeed.tech/tags/ui.md>), [youtube](<https://devfeed.tech/tags/youtube.md>)

### AI overview

QuadRF is an open-source phased-array radio built around a Raspberry Pi 5 and FPGA board. The article describes its ability to process and beamform radio signals, detect drones, observe WiFi through walls, decode RF, and support local SDR applications. It also discusses a larger Moon-scale antenna-array project and testing a prototype.

### Source excerpt

The QuadRF (pictured above) a phased-array radio built around a Raspberry Pi 5 and an FPGA board with picosecond-level timing. It does advanced signal processing and beamforming. It can see WiFi through walls and track drones in flight. If the open source community can come up with something like this, just imagine what governments are capable of. When you plug a computer into a network, tools like Wireshark can show all the hidden traffic you might not even know is there. WiFi packets are the same, but those travel through the air, allowing snooping without physical access.

## Tuning in FM Radio on a 3D Printer Heatbed

DevFeed: [Tuning in FM Radio on a 3D Printer Heatbed](<https://devfeed.tech/articles/tuning-in-fm-radio-on-a-3d-printer-heatbed-10485.md>)

Original publisher: [Read original article](<https://www.jeffgeerling.com/blog/2026/tuning-in-fm-radio-on-a-3d-printer-heatbed/>)

Author: jeff@jeffgeerling.com (Jeff Geerling)

Published: 2026-05-28T14:00:00Z

Content type: opinion

Language: en

Sources: [Jeff Geerling](<https://devfeed.tech/sources/jeff-geerling.md>)

Topics: [3D](<https://devfeed.tech/topics/3d.md>), [Nanovna](<https://devfeed.tech/topics/nanovna.md>)

Tags: [3d](<https://devfeed.tech/tags/3d.md>), [3d-printer](<https://devfeed.tech/tags/3d-printer.md>), [3d-printing](<https://devfeed.tech/tags/3d-printing.md>), [fm-radio](<https://devfeed.tech/tags/fm-radio.md>), [geerling-engineering](<https://devfeed.tech/tags/geerling-engineering.md>), [nanovna](<https://devfeed.tech/tags/nanovna.md>), [pcb](<https://devfeed.tech/tags/pcb.md>), [radio](<https://devfeed.tech/tags/radio.md>), [rf](<https://devfeed.tech/tags/rf.md>), [sdr](<https://devfeed.tech/tags/sdr.md>), [signal](<https://devfeed.tech/tags/signal.md>), [video](<https://devfeed.tech/tags/video.md>)

### AI overview

The article tests whether a 3D printer heatbed can act as an FM radio antenna. Measurements with a NanoVNA found several potentially suitable frequencies, although the heatbed traces are not optimized for radio-frequency use. Near a high-power FM tower, the heatbed received a clear stereo signal.

### Source excerpt

Pooch from Repkord dropped by my studio while he was in St. Louis, and asked a simple question: Can a 3D printer's heatbed act as an antenna? A fair question, as many an antenna is embedded in a PCB these days... and the traces on a PCB heatbed like the one used in Prusa's Core One look kinda like an antenna, if you squint the right way. Really, anything (or anyone) can be an antenna, given enough power.