Confidence: Medium · Source: FCC ULS · As of 2026-09-14
KR4OLL callsign genealogy
Currently held by Kroll, Geoffrey T
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 KR4OLL's current licensee, walking backwards.
- Kroll, Geoffrey TFLgranted 2014-05-14cancelled 2015-01-30
Successor callsigns
Callsigns held now by people who previously held KR4OLL.
No current licensee on record previously held this callsign.