Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KO4N callsign genealogy
Currently held by UNDERWOOD, DAVID D
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 KO4N's current licensee, walking backwards.
- SPRINGTHORPE, DWIGHTNCgranted 2012-10-09cancelled 2012-12-07
Successor callsigns
Callsigns held now by people who previously held KO4N.
- UNDERWOOD, DAVID DTNgranted 2010-11-16cancelled 2012-10-27
All historical holders
Every license row we've seen with the callsign KO4N, oldest first.
- SIKES, J P GA1994-05-24 → cancelled 2006-05-25
- UNDERWOOD, DAVID D TN2006-06-13 → cancelled 2010-11-16
- SPRINGTHORPE, DWIGHT PA2022-10-15 active