Confidence: Medium · Source: FCC ULS · As of 2026-09-12
NP4B callsign genealogy
Currently held by ZIMMERMAN JR, ROBERT K
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 NP4B's current licensee, walking backwards.
Successor callsigns
Callsigns held now by people who previously held NP4B.
No current licensee on record previously held this callsign.
All historical holders
Every license row we've seen with the callsign NP4B, oldest first.
- ZIMMERMAN JR, ROBERT K IL2012-05-31 → cancelled 2017-12-06
- SANTANA, JORGE L PR2019-12-27 active