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

KS1O callsign genealogy

Currently held by BUTLER, JAMES R

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 KS1O's current licensee, walking backwards.

  1. KC9COcancelled· E
    Sullivan, Michael GTNgranted 2014-04-25cancelled 2020-08-15
  2. N4FTWactive· G
    SHEETS, BRYAN DNCgranted 2018-08-07
  3. KN4KHHcancelled· T
    SHEETS, BRYAN DNCgranted 2018-03-05cancelled 2018-08-07

Successor callsigns

Callsigns held now by people who previously held KS1O.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign KS1O, oldest first.

  • BUTLER, JAMES R MA
    2008-05-13 → cancelled 2020-07-28
  • Sullivan, Michael G TN
    2020-08-15 active
← Back to KS1O License history →