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Confidence: Medium · Source: FCC ULS · As of 2026-09-12

KT1O callsign genealogy

Currently held by O BRION, THOMAS A

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 KT1O's current licensee, walking backwards.

  1. N1ZPCcancelled· E
    O BRION, THOMAS Acancelled 1999-01-13

Successor callsigns

Callsigns held now by people who previously held KT1O.

  1. W1ESactive· E
    WEDGE, STEPHEN ENCgranted 2026-08-11