This has equivalent circuit as a voltage source connectoed to load via 200ft cable.
First we need to calculate the input voltage based on the given load output.
Then replace output load and cable by 100 ohms load. With this new load calculate
output voltage.
Step 1:
Po = 56.5dBuV = 20*log(V0/1exp-6)
solving, we get
Vo = 668.34uV
therefore Po in dB is
Po = 10*log(668.34exp-6/1exp-6) = 28.25dBuW
Step 2:
The cable loss can be calculated as
Cable Loss = 4.5 * 200/100 = 9dB
Step 3:
This is power in the load of 50 Ohms.
The power at the input of the load is give by
Po = cable loss + Pin
Pin = 28.25 + 9 = 37.25dBuW = 10*log(Pin/1exp-6)
Pin = 5.31mW
Vin = sqrt (Pin*50) = 515.21mV
Step4:
No with this input, reaplce 50 Ohm load and cable by 100 Ohms load
and calculate Vo
Vo = (100 * Vin)/150 = 343.47mV
Vo = 110.72dBuV
I do not understand what is wrong with the procedure I am following.
The answer is given in the bracket in problem statement.
First we need to calculate the input voltage based on the given load output.
Then replace output load and cable by 100 ohms load. With this new load calculate
output voltage.
Step 1:
Po = 56.5dBuV = 20*log(V0/1exp-6)
solving, we get
Vo = 668.34uV
therefore Po in dB is
Po = 10*log(668.34exp-6/1exp-6) = 28.25dBuW
Step 2:
The cable loss can be calculated as
Cable Loss = 4.5 * 200/100 = 9dB
Step 3:
This is power in the load of 50 Ohms.
The power at the input of the load is give by
Po = cable loss + Pin
Pin = 28.25 + 9 = 37.25dBuW = 10*log(Pin/1exp-6)
Pin = 5.31mW
Vin = sqrt (Pin*50) = 515.21mV
Step4:
No with this input, reaplce 50 Ohm load and cable by 100 Ohms load
and calculate Vo
Vo = (100 * Vin)/150 = 343.47mV
Vo = 110.72dBuV
I do not understand what is wrong with the procedure I am following.
The answer is given in the bracket in problem statement.
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