How far can you radio someone?

Ham radio operators use the 2-meter band for general conversations as well as for emergency communications . Ham radio operators are often the first called upon to assist in major disasters with communications between the public and emergency services such a law enforcement, fire and emergency medical services.

Radio waves have the longest wavelengths in the EM spectrum, according to NASA, ranging from about 0.04 inches (1 millimeter) to more than 62 miles (100 kilometers). … Bands of radio waves. BandFrequency rangeWavelength rangeHigh Frequency (HF)3 to 30 MHz10 to 100 mVery High Frequency (VHF)30 to 300 MHz1 to 10 mWhat Are Radio Waves? | Live Science www.livescience.com › 50399-radio-waves

For this reason, a microwave radio repeater with transmitter and receiver dishes mounted on 30-metre (100-foot) towers has a maximum range of approximately 50 km (30 miles) , whereas the maximum range will increase to approximately 80 km (50 miles) if the towers are raised to 90 metres (300 feet).