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

AA4U callsign genealogy

Currently held by CARROLL, STEPHEN J

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 AA4U's current licensee, walking backwards.

  1. K2SCactive· E
    Ishikawa, TakayukiORgranted 2021-12-07
  2. AE7QEcancelled· E
    Ishikawa, TakayukiORgranted 2011-09-16cancelled 2011-12-30
  3. KF7RPNcancelled· E
    Ishikawa, TakayukiORgranted 2011-09-16cancelled 2011-12-09

Successor callsigns

Callsigns held now by people who previously held AA4U.

  1. K4RBactive· E
    BLUMBERG, ROBERT GCAgranted 2026-08-15

All historical holders

Every license row we've seen with the callsign AA4U, oldest first.

  • RICHARDSON III, FRANK T AL
    1998-11-24 → cancelled 2003-04-06
  • CARROLL, STEPHEN J AL
    2017-07-11 active
← Back to AA4U License history →