Which of the following is an appropriate receive filter to select in order to minimize noise and interference for CW reception?

Choosing a 500 Hz receive filter for CW (Continuous Wave) reception is advantageous because it effectively narrows the bandwidth of the signal being received. In CW operation, signals are transmitted as Morse code, which consists of short and long bursts of energy. A narrower filter, such as 500 Hz, allows the operator to isolate these bursts of signal more effectively while blocking unwanted noise and interference from nearby frequencies.

CW signals typically have a small bandwidth, and utilizing a filter that matches this characteristic helps to reduce the likelihood of picking up adjacent signals that could interfere with the clarity of the reception. Wider filters, like those at 1000 Hz, 2400 Hz, or 5000 Hz, would pick up more noise and unwanted signals, making it harder to accurately receive and interpret the intended Morse code transmission. Thus, the 500 Hz filter is the optimal choice for minimizing noise and enhancing the quality of CW reception.