Aspects described herein provide for a sensor assembly having an electrically isolated cable segment that may be used for geophysical prospecting. The sensor assembly generally includes a first cable segment comprising at least one electromagnetic (EM) sensor, and a second cable segment connected to the first cable segment and electrically isolated from the first cable segment. The second cable segment may be free of electrically conductive components. Alternatively, the second cable segment may have electrically conductive components that are not electrically connected to the first cable segment. The electrically isolated cable segment may reduce or eliminate undesired signal cross-feed from the EM source to the first cable segment, which may aid in maintaining data quality.