Interference Considerations affecting Channel-Frequency Assignments

A study is made of the mutual interference problems which arise when a number of stations transmitting c.w. signals and having the same frequency tolerance share a given frequency band. On the assumption that the transmitters are grouped into a number of channels spread over the frequency band, it is shown that, for a given receiver selectivity specified by its gate width, no practical advantage is gained by spacing the channel frequencies closer together than by a value which is about 75% of the nominal transmitter tolerance band-width, although (except over a limited region when the receiver gate is wider than the transmitter tolerance) a spacing equal to the nominal tolerance band-width should not be exceeded. For a given separation between channels it is demonstrated that, in general, the interference falls with reduction of the receiver gate-width.