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proteo
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Hi! I am an amateur radio operator. How many watts should my radio's power be to bounce signals off the Moon?
What is your operating wavelength ?proteo said:How many watts should my radio's power be to bounce signals off the Moon?
The optimal frequency range for moonbounce communication, also known as Earth-Moon-Earth (EME) communication, is typically in the VHF (Very High Frequency) and UHF (Ultra High Frequency) bands. Commonly used frequencies are 144 MHz (2 meters) and 432 MHz (70 centimeters), as these bands offer a good balance between manageable antenna sizes and effective signal propagation.
Antenna gain is crucial for moonbounce communication because it helps to focus the transmitted power and increase the received signal strength. High-gain directional antennas, such as Yagi-Uda arrays, parabolic dish antennas, or large multi-element arrays, are typically used. These antennas can provide the necessary gain to overcome the significant path loss encountered in EME communication.
Effective moonbounce communication generally requires high power output to compensate for the immense distance and signal loss. A minimum of 100 watts is usually recommended, but many operators use amplifiers to achieve power levels of 500 watts to 1 kW or more. Higher power increases the likelihood of successful communication, although it must be balanced with regulatory limits and equipment capabilities.
To minimize signal loss, use high-quality coaxial cables with low loss characteristics, such as LMR-400 or better. Keep cable runs as short as possible, and ensure all connectors are properly installed and weatherproofed. Additionally, using low-noise preamplifiers at the antenna feed point can help improve the overall system performance by boosting weak signals before they are further attenuated by the coaxial cable.
The moon's position is critical for successful EME communication. Operators need to track the moon's azimuth and elevation to ensure their antennas are accurately aimed. The best times for moonbounce communication are during periods of perigee (when the moon is closest to Earth) and when the moon is at a high elevation angle, which reduces atmospheric losses and ground noise. Software tools and moon tracking systems can aid in predicting and following the moon's position.