What is the effective radiated power of a...

Question 1 of 27070V86NigjjGv28uv29wFR5

What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain?

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Question 1 of 27070

What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain?

🔍 Key Concepts

• Effective Radiated Power (ERP) formula (start from transmitter power, subtract losses in dB, add antenna gain in dB) • Relationship between dB and power ratio (every 10 dB is a factor of 10 in power, 3 dB is about a factor of 2) • How to convert a total dB value into a linear power multiplier using $10^{(dB/10)}$

💭 Think About

• First, combine all the dB values (losses and gains) with the correct signs before converting anything to watts. Are the losses subtracted or added? Are the gains subtracted or added? • Once you have a single net dB value, think about how that changes the original 50 watts. Is it increasing or decreasing? By roughly how much? • Estimate: is the antenna gain enough to overcome the total losses? Should the ERP be more or less than 50 watts?

✅ Before You Answer

• Make sure you convert dB to a power ratio using the correct formula: $\text{Power ratio} = 10^{(\text{dB}/10)}$ . • Double-check that losses are negative dB and gains are positive dB when you sum them. • Before picking an answer, ask: "Is my final ERP reasonable compared to 50 watts?" – it should clearly be either greater than or less than 50 watts based on your net dB.