Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W3APO callsign genealogy
Currently held by ALTDOERFFER, FRANK H
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 W3APO's current licensee, walking backwards.
- ALTDOERFFER II, FRANK Hcancelled 1999-07-09
Successor callsigns
Callsigns held now by people who previously held W3APO.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W3APO, oldest first.
- ALTDOERFFER, FRANK H PA1998-08-03 → cancelled 1999-04-06
- ALTDOERFFER II, FRANK H PA2019-06-05 active