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

K0YR callsign genealogy

Currently held by FRAZIER, JOHN M

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 K0YR's current licensee, walking backwards.

  1. K0PYKcancelled· E
    Rieff, Thomas MMNgranted 2004-06-26cancelled 2006-09-09
  2. KC0PYKcancelled· G
    Rieff, Thomas MMNgranted 2003-05-13cancelled 2004-06-26

Successor callsigns

Callsigns held now by people who previously held K0YR.

  1. K4NPcancelled· E
    FRAZIER, JOHN MALgranted 2004-08-21cancelled 2009-03-17

All historical holders

Every license row we've seen with the callsign K0YR, oldest first.

  • FRAZIER, JOHN M AL
    1997-07-29 → cancelled 2004-08-21
  • Rieff, Thomas M MN
    2026-08-07 active
← Back to K0YR License history →