Confidence: Medium · Source: FCC ULS · As of 2026-09-14
WJ9O callsign genealogy
Currently held by MATTHIES, MICHAEL P
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 WJ9O's current licensee, walking backwards.
- Holden, David GTXgranted 2019-09-06cancelled 2021-08-03
Successor callsigns
Callsigns held now by people who previously held WJ9O.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign WJ9O, oldest first.
- MATTHIES, MICHAEL P WI2009-05-20 → cancelled 2021-06-29
- Holden, David G TX2021-08-03 active