Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W4GRU callsign genealogy
Currently held by GRUMME, WILLIAM
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 W4GRU's current licensee, walking backwards.
- GRUMME, WILLIAMFLgranted 2022-01-29cancelled 2022-05-06
Successor callsigns
Callsigns held now by people who previously held W4GRU.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W4GRU, oldest first.
- Uchaker Sr, George R AL2007-04-03 → cancelled 2019-04-04
- GRUMME, WILLIAM FL2022-05-06 active