Amateur Radio Daily

Call Sign WB4MZ0 (Numeral Zero)

By Rob Rosenberger (K4HST)

The FCC erroneously issued call sign "WB4MZ0" (numeral zero) on December 5, 1994 to the Wedixie Amateur Radio Club in Marietta, Georgia. Somebody typed it wrong into the FCC's database. The club's call sign trustee, David Budner WA4PUB, perhaps didn't notice it? The club never brought it up to the FCC.

Four-and-a-half years went by. The FCC's database continued to grow. And WB4MZ0 remained an active call sign!

In mid-1999, the FCC prepared to elevate its ULS database as the "system of record" for all call signs. That's when somebody (perhaps a database administrator?) discovered the error.

The FCC researched it and they discovered "WB4MZO" (letter) had not yet been assigned. On July 21, 1999 they canceled WB4MZ0 and issued WB4MZO to the club.

Twenty-six days later, on August 16, 1999, the FCC declared its ULS database the "system of record." Its underlying software now handles all call signs. No one manually types an amateur call sign.

If you download the ULS files, you'll see five relational database records for WB4MZ0. And you'll see nine relational database records for WB4MZO.

Wedixie Amateur Radio Club disbanded and canceled its call sign on February 22, 2024. The "O" (letter) call sign became available for vanity assignment on February 23, 2026. If you know any elmers in Marietta, ask them for more details about it!

Source: K4HST open_in_new FCC

Special Event Station CS5AIRA/M to Activate São Jacinto Military Area

The following is a message from Association International Radio Amateur (AIRA):

AIRA - Special Activation, São Jacinto Military Area, Infantry Regiment No. 10. On September 12, 2026, from 10:00 AM to 5:00 PM, AIRA will promote the activation of Infantry Regiment No. 10, located in Aveiro. We invite amateur radio operators and enthusiasts to participate in this special activity. The call sign will be CS5AIRA/M.

The activity will take place on the 20 and 40-meter bands, VHF, and UHF, including connections through the LART Lusophone Network, as well as on the DMR Digital Network via Talkgroup 268 and Talkgroup 91 on the BrandMeister platform. More information is available on the AIRA website.

AIRA - Activacao Especial, Area Militar de Sao Jacinto, Regimento de Infantaria Nº10. No dia 12 de Setembro de 2026, das 10h00 às 17h00, a AIRA promoverá a ativação do Regimento de Infantaria Nº10, localizado em Aveiro. Convidamos radioamadores e entusiastas a participarem nesta atividade especial. O indicativo será CS5AIRA/M.

A atividade ocorrerá nas bandas de 20 e 40 metros, VHF e UHF, incluindo ligações pela Rede Lusófona LART, bem como na Rede Digital DMR pelo Talkgroup 268 e Talkgroup 91 na plataforma BrandMeister. Mais informações no site da AIRA.

Source: AIRA open_in_new Special Event