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

W4SDO callsign genealogy

Currently held by O'Connell, Sean 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 W4SDO's current licensee, walking backwards.

  1. KJ4COHcancelled· G
    O'Connell, Sean DNCgranted 2008-02-28cancelled 2010-03-26
  2. KJ4CIXcancelled· G
    O CONNELL, SEAN DNCgranted 2008-02-28cancelled 2008-03-10

Successor callsigns

Callsigns held now by people who previously held W4SDO.

No current licensee on record previously held this callsign.

← Back to W4SDO License history →