Confidence: Medium · Source: FCC ULS · As of 2026-09-12
K4MTR callsign genealogy
Currently held by WATT, MARTIN D
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 K4MTR's current licensee, walking backwards.
- Ridings, Mark TWVgranted 2012-11-29cancelled 2016-07-02
Successor callsigns
Callsigns held now by people who previously held K4MTR.
- WATT, MARTIN DOHgranted 2006-06-06cancelled 2008-01-26
All historical holders
Every license row we've seen with the callsign K4MTR, oldest first.
- WATT, MARTIN D TN2005-01-04 → cancelled 2006-06-06
- Ridings, Mark T TN2026-04-09 active