WMAQ's Western Electric model 104-B 5000 watt transmitter, installed in the suburban
Elmhurst transmitter site. The new transmitter was place in service on June 2nd,
1928, replacing the Western
Electric 1000 watt model 6A in the La Salle Hotel that had served WMAQ since
late 1929. Early in 1929 WMAQ modified the transmitter, implementing dual crystal
control and 100 percent low level modulation. WMAQ was the first Chicago station
to employ 100 percent modulation.