NOTE: You need several hours of reading before using those...
Fresnel Zone Clearance SimpleMilliWatts to dBm Power Conversion
dBm to MilliWattsPower Conversion Operating System Margin
NOTE: Please be aware that these figures are based on a clear Fresnel zone. If the Fresnel zone is encroached then the operating margin may be reduced by as much as 10dB.
Effective Radiated Power (ERP) Station Transmit Calculator NOTE: Connector insertion loss is generally 0.15dBm. Coax ratings are to
manufacturer specification which we have found to be much
higher than measured.