* S-band: The S-band system was used for voice, telemetry, and television transmissions between the Apollo 11 spacecraft and Earth. The S-band transmitter on the Apollo 11 spacecraft operated at a frequency of 2.293 GHz, and the S-band receiver on the spacecraft operated at a frequency of 2.115 GHz.
* VHF: The VHF system was used for voice communications between the Apollo 11 astronauts and the Mission Control Center in Houston, Texas. The VHF transmitter on the Apollo 11 spacecraft operated at a frequency of 259.7 MHz, and the VHF receiver on the spacecraft operated at a frequency of 296.8 MHz.
* UHF: The UHF system was used for telemetry transmissions between the Apollo 11 spacecraft and the Mission Control Center. The UHF transmitter on the Apollo 11 spacecraft operated at a frequency of 400.1 MHz, and the UHF receiver on the spacecraft operated at a frequency of 458.6 MHz.
The Apollo 11 spacecraft also had a backup communications system that used a Morse code transceiver. This system was used in case of failure of the primary communications systems.
The Apollo 11 communications systems were essential for the success of the mission. They allowed the astronauts to stay in contact with Mission Control and to transmit vital data and images back to Earth.
