Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W6TMC callsign genealogy
Currently held by Costello, Timothy M
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 W6TMC's current licensee, walking backwards.
- Costello, Timothy MOKgranted 2017-07-29cancelled 2020-03-07
Successor callsigns
Callsigns held now by people who previously held W6TMC.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W6TMC, oldest first.
- PIETROK, THEODORE J CA2007-06-27 → cancelled 2019-09-19
- Costello, Timothy M OK2020-03-07 active