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K4OSO

Active1x3District 4

Competitive callsign — 5 applications filed with the FCC.

License HolderColeman Sr, Milton B

License ClassAmateur Extra

Min. Class RequiredGeneral

LocationRockville, VA

Grant DateJul 14, 2023

Expiration DateJul 14, 2033

K4OSO is a highly sought-after 1x3 format amateur radio callsign. The license is currently held by Coleman Sr, Milton B in Rockville, VA. This callsign has attracted significant interest in the amateur radio community, with 5 vanity applications filed with the FCC. The most recent was submitted by Coleman Sr, Milton B on Jun 26, 2023. K4OSO has 7 recorded FCC license history events.

CW & Voice Analysis

Morse Code

-.- ....- --- ... ---

CW Weight: 35 units(Moderate)

Voice Phonetics

Kilo Four Oscar Sierra Oscar

Readability: 7.5/10(High readability)

License History

Vanity Callsign GrantedJul 14, 2023
License IssuedJul 14, 2023
License CanceledOct 13, 2021
License ModifiedJun 29, 2020
License RenewedDec 2, 2014
License IssuedJan 22, 2005
Vanity Callsign GrantedJan 22, 2005

Vanity Application Activity

Competing applications filed with the FCC for this callsign.

Coleman Sr, Milton BFiled Jun 26, 2023
Not awardedFCC ↗
Coleman Sr, Milton BFiled Jan 4, 2005
Not awardedFCC ↗
Adams, Joshua CFiled May 5, 2003
Not awardedFCC ↗
RODRIGUEZ, JOAQUIN PFiled Jan 26, 2000

Search external databases

QRZ ↗HamQTH ↗

Explore nearby callsigns

← K4OSM K4OSQ →

FCC data as of Sep 3, 2026

Dismissed

WELLBURN, HENRYFiled Jan 26, 2000

DismissedFCC ↗

K4OSO FCC Vanity Status: 5 Competing Applications & History