Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W4MMM callsign genealogy
Currently held by WOO, NELSON
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 W4MMM's current licensee, walking backwards.
- Geib, Robert AFLgranted 2020-01-06cancelled 2020-01-25
Successor callsigns
Callsigns held now by people who previously held W4MMM.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W4MMM, oldest first.
- WOO, NELSON KY2007-12-20 → cancelled 2019-08-09
- Geib, Robert A FL2020-01-25 active