Conclusions

In the elimination of parasites from a transrnitter, the circuits should be kept as simple as possib1e to prevent complex resonance condition.. Radio frequency choke coils and shuntfeed circuits should be kept at a minimum. Wide band neutralization circuits are desirable. The grids of vacuum tubes should be effectIvely by-passed capacitively to the cathode through a capacity, and inductance added next to the plates of the tubes to eliminate shortwave parasites. If necessary, the plate or grid parasitic circuits should be damped with resistance. Inductively coupled rather than capacitively coupled Input and output circuits should be used wherever possible. The mechanical layout of a shortwave transmitter should be well planned with short lesds and compact tank circuits to keep the current where it is supposed to be and to minimize stray coupling between circuits.

G. W. Fyler September, 1935

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