7. A microwave transmitter typically requires a +8 dBm audio level to drive the input fully. If a +10 dBm level is measured, what is the actual voltage level measured? Assume a 600 Ohm system. (2.45 V)
9. Convert the following powers to their dBm equivalents:
(a) p = 1 W (30 dBm)
(b) p = 0.001 W (0 dBm)
(c) p = 0.0001 W (-10 dBm)
(d) p = 25 mW (-16 dBm)
13. A 2.15 V rms signal is measured across a 600-ohm load. Convert this measured value to its dBm equivalent. (8.86 dBm (600))
14. A 2.15 V rms signal is measured across a 50-ohm load. Convert this measured value to its dBm(50) equivalent. (19.66 dBm(50))
29. Provide two other names for Johnson noise and calculate the noise voltage output of a 1-Mohm resistor at 27°C over a 1-MHz frequency range. (128.7 mV)
30. The noise produced by a resistor is to be amplified by a noiseless amplifier having a voltage gain of 75 and a bandwidth of 100 kHz. A sensitive meter at the output reads 240 mV rms. Assuming operation at 37°C, calculate the resistor's resistance. If the bandwidth were cut to 25 kHz, determine the expected output meter reading. (5.985 kohm, 120 mV)
32. Determine the noise current for the resistor in Problem 29. What happens to this noise current?
11. An unmodulated carrier is 300 V p-p. Calculate %m when its maximum p-p value reaches 400, 500, and 600 V. (33.3%, 66.7%, 100%)
15. A 100 V carrier is modulated by a 1 kHz sine wave. Determine the side-frequency amplitudes when m = 0.75. (37.5 V)
16. A 1 MHz, 40 V peak carrier is modulated by a 5 kHz intelligence signal so that m = 0.7. This AM signal is fed to a 50-ohm antenna. Calculate the power of each spectral component fed to the antenna. (Pc = 16 W, Pusb = Plsb = 1.96 W)