What frequency is associated with the Arecibo transmitter for the message?

What frequency is associated with the Arecibo transmitter for the message?

• A. 1400 MHz
• B. 5000 MHz
• C. 2380 MHz
• D. 1000 MHz

Answer: (C)

The frequency being tested is the carrier used to push the famous Arecibo message through space. That transmission shipped at about 2.38 GHz, placing it in the S-band. Why this frequency? It provides a good balance: the large Arecibo dish can radiate a very strong, narrow-beam signal at that wavelength, while atmospheric absorption remains low enough to keep the signal clear over interstellar distances. Transmitting at 2.38 GHz also fits the hardware design of the transmitter and receiver used for the dig­ital message, which was a compact 1679-bit payload sent at a modest data rate to be reconstructible by a distant receiver. The other frequencies listed don’t correspond to the historic Arecibo message transmission, so they’re not the carrier used for that event.

The frequency being tested is the carrier used to push the famous Arecibo message through space. That transmission shipped at about 2.38 GHz, placing it in the S-band. Why this frequency? It provides a good balance: the large Arecibo dish can radiate a very strong, narrow-beam signal at that wavelength, while atmospheric absorption remains low enough to keep the signal clear over interstellar distances. Transmitting at 2.38 GHz also fits the hardware design of the transmitter and receiver used for the dig­ital message, which was a compact 1679-bit payload sent at a modest data rate to be reconstructible by a distant receiver.

The other frequencies listed don’t correspond to the historic Arecibo message transmission, so they’re not the carrier used for that event.