See
http://www.earlytelevision.org/w9xk_history.html for history on transnission transmission at Iowa University and when they changed to electronic transmission. Even though electronic Television was under development in 1933 no one was transmitting. Mechanical television was only transmitting a couple of hours a day. Television news had an article on using a 3 inch Western Electric CRT for television in 1933 but the article was only on the CRT and not much on the supporting electronics required to receive a signal over the air. These guys were television hobbiest building a receiver at home and not television manufactors. Also Don Lee in Los Angeles later broadcast Electronic television a few years later.