Confidence: Medium · Source: FCC ULS · As of 2026-09-14
N4UKC callsign genealogy
Currently held by SHEFFER, MICHAEL P
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 N4UKC's current licensee, walking backwards.
- Sheffer, Michael PFLgranted 2018-09-04cancelled 2018-09-29
Successor callsigns
Callsigns held now by people who previously held N4UKC.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign N4UKC, oldest first.
- SHEFFER, MICHAEL P AL1988-11-29 → cancelled 2000-11-30
- Sheffer, Michael P FL2018-09-29 active