BNC TO RCA 75 OHM Garmin TO G3X Adapter

RG-59/U is a specific type of coaxial cable, often used for low-power video and RF signal connections. The cable has a characteristic impedance of 75 ohms, and a capacitance of around 20pF/ft (60pF/m). The 75 ohm impedance matches a dipole antenna in free space. RG (for radio guide) was originally a unit indicator for bulk radio frequency (RF) cable in the U.S. military's Joint Electronics Type Designation System.

RG-59 is often used at baseband video frequencies, such as composite video. It may also be used for broadcast frequencies, but its high-frequency losses are too high to allow its use over long distances; in these applications, RG-6 or RG-11 is used instead. In cases where the transmission distance is too long for these media, such options as UTP (unshielded twisted pair) or fiber optic can be used. RG-59 coaxial cable is commonly used with consumer equipment, such as VCRs or digital cable/satellite receivers.