Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KF4W callsign genealogy
Currently held by Grimsley, Michael F
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 KF4W's current licensee, walking backwards.
- Grimsley, Michael FSCgranted 2011-06-08cancelled 2020-07-28
Successor callsigns
Callsigns held now by people who previously held KF4W.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KF4W, oldest first.
- SHUPE, JOHN R FL2008-05-06 → cancelled 2020-07-10
- Grimsley, Michael F SC2020-07-28 active