Confidence: Medium · Source: FCC ULS · As of 2026-09-16
KI4OIU callsign genealogy
Currently held by Speiser Jr, Joseph C
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 KI4OIU's current licensee, walking backwards.
- Speiser Jr, Joseph CFLgranted 2009-01-16cancelled 2014-08-05
Successor callsigns
Callsigns held now by people who previously held KI4OIU.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign KI4OIU, oldest first.
- Speiser Sr, Joseph C FL2006-03-24 → cancelled 2013-10-10
- Speiser Jr, Joseph C FL2014-08-05 → cancelled 2026-08-08