What is the Effective Radiated Power of an amateur transmitter, if the transmitter output power is 200 watts, the transmission line loss is 5 watts, and the antenna power gain is 3 dBd?

To calculate Effective Radiated Power (ERP), you must first determine the actual power reaching the antenna. Start with the transmitter output (200 watts) and subtract the transmission line loss (5 watts) to get 195 watts at the antenna feedpoint. Next, apply the antenna gain. A gain of 3 dBd means the antenna radiates twice as much power in its favored direction compared to a standard dipole. Therefore, you multiply the power reaching the antenna (195 watts) by a factor of 2. The result is 195 watts × 2 = 390 watts ERP.