Elenco AM/FM Radio Kit - Manual (Page 12)

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DYNAMIC MEASUREMENTS
GAIN
Figure 8
If you do not have an audio generator, skip the following test and go directly to Section 1B.
Connect the VOM and audio generator to the circuit
as shown in Figure 8.
Normally the AC gain is measured at a frequency of
1kHz. Your VOM however, may not be able to
accurately read AC voltages at this frequency.
Therefore, it is recommended that this test be
performed at 400Hz. Set the audio generator at
400Hz and minimum voltage output. With the power
ON, set your VOM to read an AC voltage of 1 volt at
test point TP1. Increase the volume control about half
way. Slowly increase the amplitude of the audio
generator until your VOM reads 1 volt AC. Leave the
audio generator at this setting and move the positive
lead of your VOM to the Jumper J3. Record the AC
input voltage to the amplifier here:
Vin = _________ volts.
You may have to change scales on your VOM for the
most accurate reading. Turn the power OFF. The AC
voltage gain of your audio amplifier is equal to the AC
output voltage divided by the AC input voltage, or
1/Vin.
Calculate the gain. The gain should be 100–180.
Gain = _________
GND
TP15
Generator
GND
TP15