Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K4MJJ callsign genealogy
Currently held by Jacobs, Matthew J
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 K4MJJ's current licensee, walking backwards.
- Jacobs, Matthew JTNgranted 2014-08-18cancelled 2019-04-09
Successor callsigns
Callsigns held now by people who previously held K4MJJ.
No current licensee on record previously held this callsign.