Confidence: Medium · Source: FCC ULS · As of 2026-09-12
W0SPY callsign genealogy
Currently held by Slack, Michael D
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 W0SPY's current licensee, walking backwards.
- SHORT, SAMUEL WKSgranted 2013-04-04cancelled 2022-01-14
Successor callsigns
Callsigns held now by people who previously held W0SPY.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign W0SPY, oldest first.
- SLACK, DONALD B MO1997-05-12 → cancelled 2006-09-10
- Slack, Michael D MO2008-08-29 → cancelled 2020-09-01
- SHORT, SAMUEL W KS2022-01-14 active