Confidence: Medium · Source: FCC ULS · As of 2026-09-12
AC5G callsign genealogy
Currently held by UNDERWOOD, MICHAEL 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 AC5G's current licensee, walking backwards.
- Tappe, Philip OTXgranted 2022-01-31cancelled 2022-02-18
Successor callsigns
Callsigns held now by people who previously held AC5G.
- ELSINGA, ROBERTFLgranted 2020-01-28cancelled 2023-08-18
All historical holders
Every license row we've seen with the callsign AC5G, oldest first.
- UNDERWOOD, MICHAEL G TX2008-07-18 → cancelled 2017-10-06
- ELSINGA, ROBERT FL2019-10-25 → cancelled 2020-01-28
- Tappe, Philip O TX2022-02-18 active