Projects › Magnetic Loop Controller
Magnetic Loop Controller
In designAmateur radioAntennasPico
Last updated 28 September 2026
A replacement control box for a Capco magnetic loop. The loop's tuning capacitor is driven by a small DC motor with no position feedback, so the controller watches forward and reflected power and hunts for the SWR dip automatically. Manual tuning is available too, with an OLED display of SWR and power.
At a glance
| Loop | Capco, 12 V DC motor, continuous rotation |
|---|---|
| Detectors | 2 × AD8307 log detectors |
| Controller | Raspberry Pi Pico 2, OLED display |
| Features | Auto-tune, manual tune, SWR and power display |
Documentation
The full design report, schematics and parts list will be published here once the project has been built, tested and filmed.