Which device is commonly used to fix rolling pictures caused by a ground loop?

An isolation transformer is a device specifically designed to eliminate ground loop issues that can cause rolling pictures in video systems. Ground loops occur when there are multiple ground points in a system, leading to differences in voltage levels. This can cause interference and unwanted artifacts in the video signal, such as rolling or flickering images.

By employing an isolation transformer, the signal path is separated from the ground, effectively breaking the electrical connection that leads to these ground loops. This helps to stabilize the video signal, ensuring that it remains clear and free of these disruptions.

While devices like amplifiers and signal boosters enhance signal strength, they do not address the root cause of ground loops. Similarly, rectifiers convert alternating current (AC) to direct current (DC) and are not relevant in this context. The isolation transformer is essential for maintaining signal integrity in systems affected by ground loop issues, making it the correct choice for this situation.