Frequency converters are key part of satellite ground stations or test facilities to secure reliable communication link between ground and space segments. Standard up- and downconverters are typically used at telecommunication, broadcast or telemetry / telecommand ground stations to transform the baseband signal into the upper region of the frequency spectrum and vice versa. Test Loop Translators (TLT) are intended to check system performance of uplink / downlink ground station without using live satellite link. Excellent RF to RF signal conversion and precisely adjustable attenuation can simulate signal transmission path for testing purposes.