Are Superpowered FM Broadcasters Affecting Mother RF Spectrum?
One day not too long ago I happened to have my spectrum analyzer connected to the outside discone broadband antenna. Out of curiosity I scanned the entire first GigaHertz of the RF spectrum, curious to see who had the strongest RF signal into my house. It turned out to be a pair of FM broadcasters. So I then focused in on the FM broadcast band spectrum. I quickly discovered two FMs who jointly held the top signals. I measured received signal levels from each station of -16 dBm. These two are the strongest measured off-premises signals at my residence between 0 and 1,000 MHz, and probably in the entire RF spectrum. When that signal level is developed across a 75 ohm receiver input, it produces more than 43,000 microvolts! Few, if any, non-broadcast broadband receiver front ends are going to handle a signal of that magnitude without folding into compression. It’s no wonder that my sensitive monitoring receivers on outdoor antennas curled up and died whenever they were tuned to within a f
