Assume that a circuit conditioner arrives to connect a telephone modem
having 600-ohm input impedance.
If his test of output impedance of
the line shows it to have 135 ohms impedance, what action should he
Raise the transmitting level to overcome line loss so normal
level enters the modem.
to be in error.
Exercises 19 through 23 are based on this situation.
voltage between each of the two wires to ground.
input and output impedance of the wire pair.
Assume that the input circuit is being tested. If the normal signal
level (0 dBm0) at the point of test is 0.636 volt, the value of V1
must be adjusted to
1 milliwatt in 600 ohms.
equal the normal signal level.
0.636 volt from either line to ground.