The Application of Superheterodyne Frequency Conversion Systems to Multirange Receivers

In this paper certain problems involved in the application of the superheterodyne circuit to high frequencies are discussed. The effects of coupling between oscillator and radio-frequency circuits are considered, and it is shown that such coupling may occur as the result of space-charge variations in the converter tube. The problem of noise reduction is considered. The means recommended for improvement of high-frequency performance are the use of higher intermediate frequencies, special circuit arrangements to avoid undesired couplings, higher minimum L/C ratios in the high-frequency bands, and the use of sufficient radio-frequency amplification to minimize noise.