Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KC0OJI callsign genealogy
Currently held by Maas, David J
The FCC publishes a previous_call_sign on
every amateur license — a self-link to the licensee's prior callsign.
Following those links produces the chain below.
Previous callsigns
Older callsigns held by KC0OJI's current licensee, walking backwards.
- SPIEKER, CASTLE TMOgranted 2023-07-19cancelled 2023-08-08
Successor callsigns
Callsigns held now by people who previously held KC0OJI.
- Maas, David JKSgranted 2019-06-04
All historical holders
Every license row we've seen with the callsign KC0OJI, oldest first.
- Maas, David J KS2002-11-08 → cancelled 2009-05-29
- Spieker, Castle T MO2023-08-08 active