Confidence: Medium · Source: FCC ULS · As of 2026-09-14
W9DCO callsign genealogy
Currently held by SADOFF, RONALD B
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 W9DCO's current licensee, walking backwards.
- Oliva, David CILgranted 2008-04-07cancelled 2008-10-21
Successor callsigns
Callsigns held now by people who previously held W9DCO.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W9DCO, oldest first.
- SADOFF, RONALD B WI1995-03-06 → cancelled 2007-03-07
- Oliva, David C IL2008-10-21 → cancelled 2017-04-12