If a repeater has a 75 watts output with a combination of 5 dB feedline loss and 4 dB duplexer loss, while also considering 6 dB of antenna gain, what is its effective radiated power?

If a repeater has a 75 watts output with a combination of 5 dB feedline loss and 4 dB duplexer loss, while also considering 6 dB of antenna gain, what is its effective radiated power?

• A. 40.4 watts
• B. 37.6 watts
• C. 50 watts
• D. 45 watts

Answer: (B)

To calculate the effective radiated power (ERP) of a repeater, you need to consider the output power, the losses in the system, and any gains from the antenna. 1. Start with the repeater's output power, which is 75 watts. 2. Subtract the feedline loss: The feedline loss is 5 dB. In terms of power, every 3 dB represents a halving of power. A 5 dB loss corresponds to about a 31.6% reduction in power. You can calculate the power after this loss with the formula: Output Power after feedline loss = 75 watts / (10^(5/10)) ≈ 75 / 3.162 = 23.7 watts. 3. Next, subtract the duplexer loss: The duplexer introduces an additional 4 dB of loss, which also needs to be accounted for. Applying the same calculations: Power after duplexer loss = 23.7 watts / (10^(4/10)) ≈ 23.7 / 2.511 = 9.43 watts. 4. Lastly, account for the antenna gain: The antenna gain is 6 dB, which means

To calculate the effective radiated power (ERP) of a repeater, you need to consider the output power, the losses in the system, and any gains from the antenna.

1. Start with the repeater's output power, which is 75 watts.

2. Subtract the feedline loss: The feedline loss is 5 dB. In terms of power, every 3 dB represents a halving of power. A 5 dB loss corresponds to about a 31.6% reduction in power. You can calculate the power after this loss with the formula:

Output Power after feedline loss = 75 watts / (10^(5/10)) ≈ 75 / 3.162 = 23.7 watts.

3. Next, subtract the duplexer loss: The duplexer introduces an additional 4 dB of loss, which also needs to be accounted for. Applying the same calculations:

Power after duplexer loss = 23.7 watts / (10^(4/10)) ≈ 23.7 / 2.511 = 9.43 watts.

4. Lastly, account for the antenna gain: The antenna gain is 6 dB, which means