One month after the Yuilles arrived, the branch office arranged Brazil’s first service convention, held in the city of São Paulo. Apparently with Maud as the driver, the sound car went into operation advertising the public lecture, which drew an attendance of 110! The convention program boosted the morale of the publishers, who were moved to increase their share in field service. They learned how to preach using literature and testimony cards, as well as phonograph recordings in English, German, Hungarian, Polish, Spanish and, later, Portuguese.

Three service conventions, held in São Paulo, Rio de Janeiro, and Curitiba in 1937, provided fresh impetus to the evangelizing work. The sound car went along with conventioners in the house-to-house work. José Maglovsky, a young lad at the time, later wrote: “We would place our Bible publications on a stand, and as the sound car broadcast a recorded message, we would talk to the people who came out of their homes to see what was happening.”

Following the conventions, every Sunday, rain or shine, recorded Bible lectures from the sound car reached people in parks, residential areas, and factories in the center of São Paulo and in nearby towns.