Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K9RMJ callsign genealogy
Currently held by Mueller, Richard 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 K9RMJ's current licensee, walking backwards.
- Mueller, Richard JILgranted 2015-10-07cancelled 2018-08-28
Successor callsigns
Callsigns held now by people who previously held K9RMJ.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K9RMJ, oldest first.
- Brewer, William W MI2005-08-12 → cancelled 2017-08-15
- Mueller, Richard J IL2018-08-28 active