What’s EME? E-Me? And who is Eve? And where is Adam in all this?

Ham Radio operators in Germany have announced that they have successfully bounced a radio signal off of the planet Venus and received the echo back on Earth. The round-trip that the radio waves made took about 5 minutes, which would make it hard to carry on a casual conversation!

Most people not familiar with Ham Radio don’t realize that Hams have been communicating by bouncing their signals off the moon since the 60’s. Recent contributions by computer software and digital signal processing techniques have made this even easier.

EME, which is an abbreviation for Earth-Moon-Earth, is now being complimented by the new acronym EVE, or Earth-Venus-Earth. The techniques used to receive such weak signals successfully entail slowing the signal down and transmitting it over a longer period of time. The computer assisted receiving software can then decipher the signal amid all the noise by watching for changes in it that happen more slowly. The method of encoding these signals? Good old Morse Code.

Another thing many people don’t realize about Ham Radio is the wide variety of frequency bands used by Hams. the EVE transmissions occurred on 2.4 GHz. That’s Giga-Hertz, not Mega or Kilo, and it’s approximately the frequency your microwave oven uses. The German Hams used about 6 kilowatts with a dish antenna to accomplish the feat.

While Hams do use short wave frequencies, which are anywhere from 1.8 to 28 MHz. many Hams also use frequencies in the VHF and UHF and even into the Microwave range of frequencies. These frequencies are less dependent on the ionosphere and generally work on a point-to-point basis. Hams have found many inventive ways of extending the range of these line-of-sight frequencies including repeater stations and even bouncing the signals off of everything from mountains, to atmospheric features, to Aurora Borealis, to the Moon and now Venus.

More details on the EVE experiment can be found at the ARRL web page.