Confidence: Medium · Source: FCC ULS · As of 2026-09-14
K9MGM callsign genealogy
Currently held by MARQUEZ MR, MARIO G
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 K9MGM's current licensee, walking backwards.
- GROETZENBACH JR, ROBERT GILgranted 2016-03-03cancelled 2023-03-21
Successor callsigns
Callsigns held now by people who previously held K9MGM.
- MARQUEZ, MARIO GWIgranted 2024-05-29
All historical holders
Every license row we've seen with the callsign K9MGM, oldest first.
- MARQUEZ MR, MARIO G WI2010-05-21 → cancelled 2014-07-22
- GROETZENBACH JR, ROBERT G IL2023-03-21 active