Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4MRB callsign genealogy
Currently held by Butler, Thomas R
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 K4MRB's current licensee, walking backwards.
- Butler, Thomas RNCgranted 2020-06-15cancelled 2020-07-03
Successor callsigns
Callsigns held now by people who previously held K4MRB.
- MOYER, WILLIAM MFLgranted 2017-02-17
All historical holders
Every license row we've seen with the callsign K4MRB, oldest first.
- MOYER, WILLIAM M FL2008-12-09 → cancelled 2017-02-17
- Butler, Thomas R NC2020-07-03 active