The following lines were added (+) and removed (-):
Maximum Usable Frequency. Operational MUF is the highest frequency you can operate with your specific working conditions and equipment to communicate with another specific station. MUF is dependent on ionospheric radio propagation. Frequencies including the Critical Frequency; Lowest Usable Frequency, LUF; Maximum usable frequency, MUF; and the Optimum Working Frequency, OWF are all relevant when determining which frequencies will provide the best performance for a short wave radio, and HF 2-way radio communications.Maximum Usable Frequency. Operational MUF is the highest frequency you can operate with your specific working conditions and equipment to communicate with another specific station. MUF is dependent on ionospheric radio propagation. Frequencies including the Critical Frequency; Lowest Usable Frequency, LUF; Maximum usable frequency, MUF; and the Optimum Working Frequency, OWF are all relevant when determining which frequencies will provide the best performance for a short wave radio, and HF 2-way radio communications. Know your international / DX beacons that you can tune to so that you can determine the current MUF.