In 1929, regulations were enacted that banned the use of spark-gap transmitters on all amateur radio bands. Spark-gap technology, which had been the foundation of early radio communication, was increasingly seen as inefficient and disruptive due to its wideband emissions, which caused significant interference across multiple frequencies. The transition to continuous wave (CW) and other more modern and efficient modes of transmission, such as amplitude modulation (AM) and later single sideband (SSB), allowed for clearer, more reliable, and more spectrally efficient communication. This ban marked a significant advancement in amateur radio, promoting the use of more advanced technologies and improving the overall quality of radio communications.
