Question 6A486

To receive radiotelegraph (CW) signals through interference with a regenerative receiver, you need to maximize the receiver's ability to discriminate against unwanted signals. **Option A is correct** because regenerative receivers achieve their highest selectivity and gain by operating just below the point of oscillation. At this critical point, the Q factor of the tuned circuit is significantly increased, creating a very narrow bandwidth (maximum selectivity). This sharp filtering allows the receiver to "ring" at the incoming CW signal's frequency, providing an audible beat note while rejecting closely spaced interference. Maximizing gain also helps in picking up weak signals. **Option B is incorrect.** Increasing the degree of coupling between the antenna and grid coils can broaden the receiver's bandwidth and reduce selectivity, making it more susceptible to interference. It can also make the receiver unstable or prone to "pulling" the resonant frequency. **Option C is incorrect.** Providing minimum possible regeneration would result in very low gain and very broad bandwidth, making it impossible to effectively receive weak CW signals amidst interference. CW reception heavily relies on the regenerative process for both sensitivity and sharp selectivity.