and on at least one occasion, they monitored the EVA suit radios on the surface of the moon from their ham shacks on earth confirmed by the fact that their directional antennas were pointed at the moon and had to be readjusted to compensate for the rotation of the Earth.
http://www.southgatearc.org/news/august2012/apollo_11_heard_by_ham_radio_operator.htm
I've written about this guy (Larry Baysinger) several times; you might find it in the archives.
Not only did he receive Neil Armstrong's backpack transmitter directly from the moon, his recording exhibits exactly those features that someone knowledgeable about radio modulation and propagation would expect to hear. The signal strength, for example, varies slowly from quite readable to unreadable. This is exactly what you'd expect given that the moon was just setting at Baysinger's location in Kentucky, and the moon is passing through "Fresnel zones" as it sets. His antenna picks up not only the direct path from the moon but also a reflected signal off the ground, and the relative lengths of these paths changes as the moon sets. At times the two components add in phase and the signal is enhanced; at other times they are out of phase and cancel, so the signal fades.
This phenomenon is will known to ham "moonbouncers" who sometimes use it to make contacts they otherwise wouldn't be able to make because their antennas are too small and/or they're not using enough power. They use very short transmissions that can complete during an enhancement peak.
Armstrong's transmitter used AM (same as aeronautical radio) on a high VHF frequency. It was intended only to reach the LM for relay to earth by S-band. Had Baysinger tried to receive the LM's S-band signal (the one
intended to reach earth) he actually would have failed because it was transmitting wideband FM to carry video. This is an all-or-nothing proposition that required very large dishes (64 meters at Goldstone, California and Parkes, Australia). He heard both Armstrong and Aldrin because Armstrong's radio relayed Aldrin's voice, which was FM on a separate VHF frequency; had Baysinger listened for that, he probably also would have failed. He did not hear Capcom, as expected.
And the signal faded out completely during the EVA as the moon set in Kentucky, and Baysinger went into the house to watch the rest of it on TV.
Other hams did receive voice from later missions' CSMs in lunar orbit while it was transmitting PM (narrowband phase modulation), which is much easier to receive with small antennas.
