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

W4RRT callsign genealogy

Currently held by OSTBY II, 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 W4RRT's current licensee, walking backwards.

  1. WT4AOcancelled· A
    OSTBY II, THOMAS AGAgranted 2016-11-01cancelled 2019-11-30

Successor callsigns

Callsigns held now by people who previously held W4RRT.

  1. WT4AOcancelled· A
    OSTBY II, THOMAS AGAgranted 2016-11-01cancelled 2019-11-30

All historical holders

Every license row we've seen with the callsign W4RRT, oldest first.

  • OSTBY II, THOMAS A GA
    2007-03-10 → cancelled 2016-11-01
  • OSTBY II, THOMAS A GA
    2019-11-30 active
← Back to W4RRT License history →