The type of the specific vaccum tap switch which i study is bpkal50 - 10 / 35 - 9c . this tap switch is suitable for 6 - 10kv - voltage degree which maximum current rating is 150a and maximum usable frequency is 50hz 课题具体研制的真空开关型号为bpk 150 ? 10 / 35 ? 9c 。它适用于电压等级为6 ? 10kv ,最大额定通过电流为150a ,额定频率为50hz ,三相任意连接的干式电力变压器。
In radio transmission maximum usable frequency (MUF) is the highest radio frequency that can be used for transmission between two points via reflection from the ionosphere ( skywave or "skip" propagation) at a specified time, independent of transmitter power. This index is especially useful in regard to shortwave transmissions.