How is radio distance calculated?

That formula is: Horizon in kilometers = 3.569 times the square root of the antenna height in meters. For example, if the antenna height of a radio is at 6 feet (1.82880 meters tall) the horizon is 2.99 miles away (4.83 kilometers) and another radio with the antenna at 6 feet, that equals approximately a 6-mile range.

How far can a radio signal travel?

So realistically, for two people carrying a handheld two-way radio, the maximum communication distance on flat ground with no obstructions is around 4 to 6 miles. So you may be wondering why you see radios that have range claims of 25 miles or higher. Technically they could communicate that far.

What determines how far a signal can travel?

Frequencies below 2MHz (Megahertz) are reflected off the atmosphere, thus they can follow the Earth’s curvature. So these low frequency signals can sometimes be received by radios below the horizon hundreds of miles away. As a general rule, the lower the frequency, the greater distance it can travel.

How far does an FM radio signal travel?

Reception distance VHF radio waves usually do not travel far beyond the visual horizon, so reception distances for FM stations are typically limited to 30–40 miles (50–60 km).

How far can a 40 watt radio transmit?

With 40W (46 dBm) ham radio (and 2 dBd antennas on both ends) and you can work around 50 000 km on VHF band and around 400 000 km on HF band when you have direct line of sight.

How far can a 10 meter radio transmit?

“SHORT SKIP” on ten meters is usually around 500 miles or less and normal skip propagation “Sky Wave” can vary from a thousand to several thousand miles and around the earth. During the height of a sun spot cycle, signals can be heard both near and far for a large part of the 24 hour day.

How far will a 25 Watt VHF radio transmit?

For example, a 25-watt marine radio will roughly have a maximum range of 60 nautical miles (111 km) between antennas mounted on tall ships, but that same radio will only have a range of 5 nautical miles (9 km) between antennas mounted on small boats at sea level.

How far can a UHF radio transmit?

Add obstructions or interference, and most UHF two-way radios have a realistic range of between 1 to 4 miles.

How far do FM transmitters work?

Being low-powered, most transmitters typically have a short range of 100–300 feet (30–100 metres), depending on the quality of the receiver, obstructions and elevation.

How Far Will 8 watts transmit?

From the air it gets even better. Most airband radios are 5 – 8 watts and typically have a range of around 200 miles.

Frequencies below 2MHz (Megahertz) are reflected off the atmosphere, thus they can follow the Earth’s curvature. So these low frequency signals can sometimes be received by radios below the horizon hundreds of miles away. As a general rule, the lower the frequency, the greater distance it can travel.

What is the speed of a radio signal?

Radio signals are electromagnetic waves, such as light or X-ray. The speed of electromagnetic waves in vacuum, is 300000km/sec (approximately). In order to calculate the time of travel with this speed from Earth to Mars, we need to know the distance.

How far can you travel with a 5 watt two-way radio?

So according to our rule-of-thumb, 2 people around 6 feet tall using a 5 watt handheld two-way radio, used on flat ground with no obstacles, will have a maximum range of approximately 6 miles. Are you guaranteed to get 6 miles? No.

How far can radio waves pass through Metal?

In between is a metal wall with a three foot opening. Radio waves cannot pass through metal. The UHF wavelength is roughly one and a half feet wide, the VHF wavelength is roughly five feet wide. The UHF signal (1 1/2 ft) passes through the door easily. However, the VHF signal is reflected since it is wider than the door.