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

KV4IO callsign genealogy

Currently held by BUTKIEWICZ SR, JOSEPH F

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 KV4IO's current licensee, walking backwards.

  1. KA1CTFcancelled· A
    BUTKIEWICZ SR, JOSEPH FGAgranted 2009-07-18cancelled 2009-07-20
  2. KB1ZAactive· A
    BUTKIEWICZ SR, JOSEPH FGAgranted 2025-07-15
  3. KA1JFBcancelled· A
    BUTKIEWICZ SR, JOSEPH FGAgranted 2021-03-12cancelled 2025-07-15

Successor callsigns

Callsigns held now by people who previously held KV4IO.

  1. KB1ZAcancelled· A
    BUTKIEWICZ SR, JOSEPH FGAgranted 2018-04-24cancelled 2021-03-12
← Back to KV4IO License history →