Confidence: Medium · Source: FCC ULS · As of 2026-09-12
NT6O callsign genealogy
Currently held by MILLIGAN, HARRY I
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 NT6O's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held NT6O.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign NT6O, oldest first.
- MILLIGAN, HARRY I CA1997-11-13 → cancelled 2009-11-14
- RIDDLE, JOHN A CA2020-02-22 active