Confidence: Medium · Source: FCC ULS · As of 2026-09-14
N1SDX callsign genealogy
Currently held by Peterson, John 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 N1SDX's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held N1SDX.
- Peterson, John SRIgranted 2026-03-24
All historical holders
Every license row we've seen with the callsign N1SDX, oldest first.
- MARTELL, WILLIAM T NH1994-07-07 → cancelled 2006-07-08
- Peterson, John S RI2026-02-24 → cancelled 2026-03-24