Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AB5U callsign genealogy
Currently held by MUMPHREY II, CHARLES 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 AB5U's current licensee, walking backwards.
- MUMPHREY II, CHARLES RTXgranted 2005-04-08cancelled 2011-01-22
Successor callsigns
Callsigns held now by people who previously held AB5U.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign AB5U, oldest first.
- BROWN, DONALD S TX1998-11-25 → cancelled 2010-11-27
- MUMPHREY II, CHARLES R OK2021-01-05 active