Confidence: Medium · Source: FCC ULS · As of 2026-09-12
WA1GIO callsign genealogy
Currently held by HORENSTEIN, MARK N
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 WA1GIO's current licensee, walking backwards.
- Horenstein, Mark NMAgranted 2017-12-06cancelled 2018-02-06
Successor callsigns
Callsigns held now by people who previously held WA1GIO.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign WA1GIO, oldest first.
- HORENSTEIN, MARK N MA1989-03-14 → cancelled 2001-03-15
- Horenstein, Mark N CO2018-02-06 active