Confidence: Medium · Source: FCC ULS · As of 2026-09-09

KF4SS

Active

Madderra, Robert L

Location: Atlanta, GA
Class: Amateur Extra
Granted: 2025-04-11
Expires: 2035-04-22
Previous call: AI4JS
FRN: 0012294336

Get notified about status changes and vanity availability for this callsign.

Vanity availability

Held

Currently held

KF4SS is held by an active license; it isn't a vanity slot right now.

Vanity availability dates are computed from FCC §97.19's hold periods: 2 years from the cancellation date for cancelled or terminated licenses, 4 years from the expiration date for expired licenses (2-year renewal grace + 2-year hold).

Callsign genealogy

Full chain →

Previously held by current licensee

AI4JScancelled· E
Madderra, Bob LGAgranted 2004-12-10cancelled 2005-04-22
KI4HZMcancelled· E
Madderra, Bob LGAgranted 2004-12-10cancelled 2005-03-23

License history

0 events

No recorded events.

More vanity slots coming available

From Georgia

All →

KG6NEC 2026-09-09
KG4VAA 2026-09-10
KK4LOC 2026-09-11
KK4LOG 2026-09-11
KK4LOH 2026-09-11

Starting with KF4

All →

KF4WUR VA · 2026-10-01
KF4BCO FL · 2026-10-09
KF4WLA FL · 2026-10-11
KF4QOP KY · 2026-11-16
KF4TYA FL · 2026-11-22

Full history → Vanity availability → Callsign genealogy →