Including an example troubleshooting section could help. Like, if the compressor won't start, check the power supply, fuses, motor, etc. Also, for noise or vibration issues, check loose parts or worn components.
Because it operates on MF/HF frequencies, it can bounce signals off the atmosphere to communicate thousands of miles away, far beyond the reach of standard VHF radios. Связь и Радионавигация Finding the Manual Samyung Srg-150 Dn Service Manual