Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AB0IM callsign genealogy
Currently held by Mertz, Ian G
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 AB0IM's current licensee, walking backwards.
- Mertz, Ian GCOgranted 2004-08-12cancelled 2009-07-03
Successor callsigns
Callsigns held now by people who previously held AB0IM.
- SIEFERS, JOHN ECOgranted 2019-08-06
All historical holders
Every license row we've seen with the callsign AB0IM, oldest first.
- SIEFERS, JOHN E CO1999-04-15 → cancelled 1999-10-28
- Mertz, Ian G CO2019-06-05 active