AdvancedA-003-002-008

What is the output PEP of an unmodulated carrier transmitter if a wattmeter connected to the transmitter output indicates an average reading of 1060 watts?

A
Answer
Transmitters and receivers
Type
A
1060 watts
B
2120 watts
C
1500 watts
D
530 watts

Answer Notes

Peak Envelope Power (PEP) is defined as the average power supplied to the antenna transmission line during one radio frequency cycle at the crest of the modulation envelope. For a constant, unmodulated carrier (like a steady CW signal with no keying), the amplitude never changes. There are no peaks or valleys in the modulation envelope. Therefore, the peak envelope power is exactly the same as the continuous average power. Since the wattmeter reads an average of 1060 watts for this unmodulated carrier, the PEP is also 1060 watts. Distractor options like 2120 watts attempt to trick you into applying a multiple (like you would for certain modulated signals), which is incorrect for an unmodulated signal.
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What is the output PEP from a transmitter if an oscilloscope measures 500 volts peak-to-peak across a 50-ohm dummy load connected to the transmitter output?
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What is the output PEP from a transmitter, if an oscilloscope measures 400 volts peak-to-peak across a 50 ohm dummy load connected to the transmitter output?