Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WD4MSF callsign genealogy
Currently held by KRUER, HAROLD H
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 WD4MSF's current licensee, walking backwards.
- Kruer, Joshua MOHgranted 2019-06-26cancelled 2019-07-19
Successor callsigns
Callsigns held now by people who previously held WD4MSF.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign WD4MSF, oldest first.
- KRUER, HAROLD H KY1988-03-22 → cancelled 2000-03-23
- Kruer, Joshua M OH2019-07-19 active