I’m completely clueless about HAM radio systems. I keep hearing that they can harm the user if the user doesn’t know what they are doing.

Question

Since I know nothing about this subject, I decided to come to because it’s probably best if it’s explained that way.

How do these radios hurt people? Have people been hurt before?

In: 4

Answer 1

I’m a bit late to the party. But I am an amateur radio operator, and I can answer your question.

“HAM” is an acronym for *High Frequency Amateur Radio.* Though in common usage, HAM Radio refers to the hobby in general.

Studies about the effects of electromagnetic field strength on human health are inconclusive. By far the greatest hazard from radio communications is from RF burns, which are a type of electrical burn.

It’s a bit complex, but radio antennas work because they are designed to be electrically resonant for a specific range of transmission/reception frequencies. When RF energy is sent to an antenna, current flows easily at centre of the antenna, but has nowhere to go near the ends. This causes large voltages to form near the tips of the antenna (some antennas have 2 or more exposed elements). The more power a transmitter sends to an antenna, the higher these voltages become.

When person touches (or comes very close to) the end of an antenna with with sufficient voltage, electricity will arc into their flesh and cause a burn. What’s more, the energy radiated from an antenna can induce electrical currents in nearby metal objects. If these objects are also resonant, and close enough to the source of the RF energy, they too can produce enough voltage to cause an RF burn, even though such objects are not directly connected to the radio system.

Low powered VHF/UHF ( 50MHz-~450MHz, 0-10 Watts) radios present the least risk. However even at low power (less than 100 Watts) the antennas of HF radios (1,800KHz – 50MHz) can generate RF burns. Even very low powered HF radios (less than 5 Watts) can generate enough voltage at the end of the antenna to produce a “tickle” when touched. When HF stations get up into the Kilo-Watt range, antenna voltages can become lethal.

This is why amateur radio operators must pass knowledge tests to earn a license that authorizes them to operate such equipment.