re: Pager transmitters and intermod

The biggest problem with paging transmitters is that, depending on the frequency, they tend to operate 500 watts ERP to 3,000 watts ERP. They also simulcast their transmissions from multiple antenna sites within a given area to ensure delivery of the paged message to a small receiver, with integrated antenna, on person's hip, who is walking in an underground parking garage or riding a steel enclosed elevator. In other words, their signals are transmitted with overwhelming fire power that wipes out the front ends of most radios. Depending on the sites, they also tend to be transmitting continuously or nearly so (unlike many voice repeaters). The result is intermod everywhere.

While some undoubtedly have "bad signals", usually they are clean, but just overwhelmingly strong. Most receivers cannot deal with that much RF spewing forth all the time. Unfortunately, the only solution is to install a bandpass filter on your receiver front-end, and/or a notch filter on top of the paging frequency. And yes, even repeaters with resonator cavities have to take extraordinary measures, especially if located on the same tower!

Ed, KF7VY

The effect is overwhelming fire power or signal strength.