by Bill Ruck, San Francisco Broadcast Engineer
THE RADIO
FREQUENCY
SPECTRUM PUZZLE
THE RADIO FREQUENCY SPECTRUM
The Radio Frequency (RF) spectrum is generally considered the band of electromagnetic energy from 3 KHz to 300 GHz.
For the fi rst forty years or so, only the lower frequencies were considered useful, and frequencies above about 30 Mc/s (the
older term "Megacycles per second") were considered "useless." However, developments in the 1930s and especially the
technology developed during World War II, expanded the useful spectrum through the microwave frequencies. By about
1970, almost the entire radio frequency spectrum was allocated to some use.
In order to understand what is happening with the UHF television band and how it has an impact on the use
of this band for wireless microphones, one needs to take a look at several different aspects of the situation.
FIGURE 1
PART 1
