Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4MH callsign genealogy
Currently held by Oldham, Michael S
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 K4MH's current licensee, walking backwards.
- Oldham, Michael STNgranted 2019-11-20cancelled 2020-01-24
Successor callsigns
Callsigns held now by people who previously held K4MH.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign K4MH, oldest first.
- POOLE JR, HENRY B NH1996-02-05 → cancelled 2005-12-16
- Dalton, William R FL2008-01-04 → cancelled 2018-08-21
- Oldham, Michael S TN2020-01-24 active