N9TPB FCC License Search
🕒 FCC license data updated today 7:15 am CDT (FCC files through Oct 14, 2026) · next update tomorrow 6:00 am CDT
Ask: HAMs within 5 miles of N9TPB · Extra class operators in Madison, WI · or try N9TPB · K9* wildcards · Smith, John · 0004797601 (FRN) · 53703 · Madison, WI · old CB calls like KHC1939 or 18Q3518 (1962–63 CB call books) · (205) 546-1767 (1990s CB directory phones)

KJ4DU HAM

✅ Available for a vanity request — free since May 11, 2016.
2x2 call: Advanced and Amateur Extra licensees can request it. No pending applications list it.

📬 QSL: no LoTW uploads on record · not eQSL AG · QRZ · HamQTH

Not currently held · 1 holder on record · available since May 11, 2016

Previous holder: TEX K MONROE

Held KJ4DU May 17, 1985 → May 10, 2014 · first licensed May 17, 1985 as KJ4DU · 1 license · FRN 0008800658
📖 In the printed callbooks since 1981 as KA4OHB, before the FCC's online records

Callbook Records, 1993–2003
From the FCC amateur database as published on the QRZ! callsign CD-ROMs, 1993–2003, before and alongside the FCC's online records (which start in 1999). "Seen" dates are the first and last disc showing that record; the issue date is the FCC's, so it can be a renewal of an even older license.
Address history
From FCC database snapshots (2004 → now). "Seen" dates are the first and last snapshot showing that address.
KJ4DU in the Printed Callbooks, 1909–1997
From scanned copies of the printed callbooks (government lists from 1913, then the Radio Amateur Callbook to 1997), read by OCR, so names and streets can carry typos. Each line is one or more editions in a row showing the same name at the same address.

📡 On the Air: APRS, Digital & WSPR Spots

No APRS positions, PSK Reporter reports or WSPR spots for KJ4DU in the last 24 hours. They show up here within seconds of KJ4DU beaconing on APRS, being heard on FT8, FT4 and other digital modes, or sending a WSPR beacon.