uls-tracker
Sign in
Confidence: Medium · Source: FCC ULS · As of 2026-09-12

N4JFX callsign genealogy

Currently held by KROELINGER JR, WILLIAM L

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 N4JFX's current licensee, walking backwards.

  1. N4JFFcancelled· G
    FULLER, JERRY FSCgranted 2020-01-24cancelled 2021-07-07
  2. N4PYJcancelled· G
    FULLER, JERRY FSCgranted 2012-02-24cancelled 2020-01-24
  3. K4PYJcancelled· G
    FULLER, JERRY FSCgranted 2008-09-18cancelled 2012-02-24
  4. KD4PYJcancelled· G
    FULLER, JERRY Fcancelled 1998-12-15

Successor callsigns

Callsigns held now by people who previously held N4JFX.

No current licensee on record previously held this callsign.

All historical holders

Every license row we've seen with the callsign N4JFX, oldest first.

  • KROELINGER JR, WILLIAM L NC
    1988-08-09 → cancelled 2000-08-10
  • Sivley, Christopher G AL
    2009-06-05 → cancelled 2021-06-07
  • Fuller, Jerry F SC
    2021-07-07 active
← Back to N4JFX License history →