Prior to the Rural Electrification Act of 1936, the vast majority of rural farms in America did not have electricity. Many rural areas of the Midwest and South did not receive commercial power until the 1960s. Until that point, special radios were made to run on DC power. The earliest so-called "farm radios" used the "A", "B", and "C" batteries typical of 1920s radio sets; these farm radios were identical to those used in cities. Somewhat later, farm radios were made to be run on 6 volts from a car or tractor battery, using an electromechanical vibrator to create a pulsating DC current that could be stepped up though a transformer to create the high voltage needed for the plates of the tubes- exactly as contemporary car radios did. Other farm radios were designed to run on 32 volts DC, from a bank of lead-acid storage batteries charged from a gas powered generator or a wind-charger. The 32-volt system could also power other specially made appliances as well as electric lights around the farm. Other farm radios, especially from the late 1930s to the 1950s, reverted to using a large "A-B" dry cell that provided both 90 volts for the tube plates and 1. 5 volts for the tube filaments, as did most tube-based portable radios of that era.