ARRL Technician Practice Exam

Where should the negative return connection of a mobile transceiver's power cable be connected?

1. To a chassis ground inside the vehicle

2. At the battery or engine block ground strap

3. To the car body only

4. To the negative terminal of the battery only

The correct answer is: At the battery or engine block ground strap

The best practice for connecting the negative return of a mobile transceiver's power cable is to attach it to a ground point such as the battery or engine block ground strap. This method ensures that there is a solid and low-resistance electrical connection, which is crucial for reliable operation and performance. By connecting to the battery or engine block ground strap, you are minimizing the potential for ground loops that can introduce noise and interfere with the performance of the transceiver. A direct connection to the negative terminal of the battery provides a dependable reference point for the power supply and helps maintain voltage stability. While connecting to the vehicle's chassis or car body might seem convenient, it can lead to variable resistance and potential issues as the connections may corrode or weaken over time. Thus, grounding to the battery or engine block promotes a more effective and safer installation for mobile communications equipment.