Confidence: Medium · Source: FCC ULS · As of 2026-09-12
KF4FOL callsign genealogy
Currently held by CARLSON, DAVID J
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 KF4FOL's current licensee, walking backwards.
- Smith, Marcus DKYgranted 2025-02-27cancelled 2025-04-05
Successor callsigns
Callsigns held now by people who previously held KF4FOL.
- CARLSON, DAVID JMDgranted 2015-10-06cancelled 2017-01-28
All historical holders
Every license row we've seen with the callsign KF4FOL, oldest first.
- CARLSON, DAVID J MD2005-10-25 → cancelled 2014-02-13
- Smith, Marcus D KY2025-04-05 active