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摘要

G3VA looks more closely at super-regenerative receivers. He also describes 17SWX's new simple double-balanced mixer-demodulator using only a single transformer, yet capable of achieving more than adequate performance. In a follow-up to his item on repairing and restoring old receivers, he covers different valve cathode types and gives words of caution on replacing thermionic diodes with solid-state types. More enigmas surrounding the HRO are aired, and an improved design of signal-frequency crystal filter is described.