Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AB4O callsign genealogy
Currently held by SWISHER, JOHN B
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 AB4O's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held AB4O.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign AB4O, oldest first.
- HEXAMER, HOMER L FL1999-03-23 → cancelled 2000-04-10
- SWISHER, JOHN B TN2017-01-12 active