John Ball KN4OLA
Cybersecurity, public safety, communications, aviation, Scouting, and practical projects built for the real world.
Latest from the notebook
Recent field notes, build logs, lessons learned, and the occasional rabbit hole.
Building an ESP32 High-Altitude Balloon Camera: From First Boot to GO FOR LAUNCH
Build a small ESP32 balloon camera with microSD storage, battery power, a GO FOR LAUNCH Wi-Fi beacon, and autonomous recovery. Includes firmware…
Reprogramming a Graw DFM-17 Radiosonde with RS41ng: Soldering, SWD, WSL, and the Manual-Reset Trick
I recently decided to repurpose a recovered Graw DFM-17 radiosonde as a 70-centimeter amateur-radio tracker for our 2026 Jamboree on the Air…
Keeping NinjaOne Online During CrowdStrike Network Containment (NA Region)
Network containment is one of the most useful response controls in CrowdStrike Falcon. When a host may be compromised, containment quickly isolates…
What I work on
Different disciplines, usually the same goal: make useful systems work reliably in the real world.
Cybersecurity
Security architecture, incident response, defensive operations, monitoring, and lessons learned where availability actually matters.
Cybersecurity posts →Communications & Amateur Radio
Winlink, RF experimentation, satellites, portable communications, resilient field kits, and infrastructure-independent communications.
Amateur Radio →Public Safety & Field Operations
Law enforcement, aviation, UAS, situational awareness, mission planning, and operational technology.
About my work →Scouting & Radio Scouting
Youth-led leadership, outdoor programs, amateur radio, communications training, and practical field resources.
Scouting resources →Projects & live systems
Systems and tools I operate, maintain, experiment with, or routinely disappear into.
A working notebook.
This is not a polished brochure. It is where I document what I build, test, secure, repair, deploy, and occasionally break. Expect field notes, practical references, project write-ups, and the occasional “well, that escalated quickly” postmortem.