Direct Reception TV
So what's causing the baby monitor to pick up the NASA video? In the past, we've written about how people might be able to listen in on audio-only baby monitors. In this case, it all comes down to what the Meilingers' video baby monitor really is: a TV, complete with built-in antenna. Before we go into the details of what's happening here, let's talk a bit about radio and television frequencies.
Most people get their TV through cable or satellite. However, some still get their TV the old fashioned way through direct reception, which requires an antenna to pick up the TV signal broadcast through the air. With the inception of television, a large number of radio frequencies were set aside to broadcast TV. Early on, television was limited to channels 2 through 13, which were called Very High Frequency (VHF) channels. After World War II, more channels were assigned for TV use; these were called Ultra High Frequency (UHF) channels.
In recent years, due to the proliferation of so many different types of over-the-air communication -- including radio, television, cell phones, military communications and WiFi -- some channels have been reassigned to other uses. Today, channels 2 through 13 are still VHF channels. Channels 14 through 69 are UHF channels. Channels 70 through 83 were reassigned to cell phone frequencies in the early 1980s, and in 2009, channels 52 through 69 will be reassigned to broadcast HD channels.
In the next section, we'll see how all of this fits into the mystery.