- Portable home phones use a 2.4 GHz radio signal to communicate between a hand unit and its base station. Like all radio signals, this counts as a form of EMF radiation. Though a phone wired to a wall jack with a cable doesn't use radio waves, it too produces EMF, though at much lower frequencies. Every cell phone has a radio transmitter inside, working at frequencies between 850 and 1900 MHz and consequently producing EMF radiation.
- Microprocessors and other electronics in computers use pulses of electrical energy at billions of cycles per second. Though computer cases provide some radio shielding, they too produce EMF and can interfere with other equipment. As of 2011, many computers use wireless networking for local and Internet connections. The wireless network transmits and receives data over radio waves similar to those produced by portable phones. As it uses and radiates energy into the immediate environment, wireless networking is another source of high-frequency EMF radiation.
- Any device that uses an electric motor produces EMF at frequencies related to the motor's speed. Inside a direct current (DC) motor, conducting brushes make and break contact with an armature, producing tiny sparks as the motor spins. The sparks transmit EMF radiation in a range of frequencies up to those of radio waves. Alternating current (AC) motors also produce some EMF, though at lower frequencies than DC motors, as AC motors do not generate sparks.
- Citizen's band (CB) radios transmit at frequencies of about 27 MHz at legal power levels of up to 12 watts, with illegal equipment transmitting up to a few thousand watts. Amateur, or "ham," radio operates in various well-established frequency bands from 1.8 to 1,240 MHz and at power levels of several watts up to 100 watts. Ham radio operators offer some of the best evidence of the relative safety of EMF radiation, as they represent thousands of people exposed to several watts of energy over many decades.
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