A transmitter has an output of 2000 watts PEP. The transmission line, connectors and antenna tuner have a composite loss of 1 dB, and the gain from the stacked Yagi antenna is 10 dBd. What is the Effective Radiated Power (ERP) in watts PEP?

First, calculate the net gain of the antenna system in decibels. The antenna has a gain of 10 dBd and the feedline/connectors introduce a 1 dB loss. This results in a net system gain of 9 dB. A 9 dB gain is equivalent to a power multiplier of approximately 8. You can easily calculate this using the 3 dB rule, where every 3 dB doubles the power. Since 9 dB is three 3 dB increases (3 + 3 + 3), the power doubles three times: 2 x 2 x 2 = 8. Multiplying the original transmitter output of 2000 watts by the power multiplier of 8 gives an Effective Radiated Power (ERP) of 16 000 watts. Selecting 20 000 means the 1 dB loss was ignored.