Static measurements – Elenco SEE AMFM108CK User Manual

Page 35

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STATIC MEASUREMENTS

-34-

Figure 29

TP15

COM V

V

TP15

V

COM

V

Battery

Figure 28

Connect your VOM to the circuit as shown in Figure 29.

Turn the power ON. The voltage at the emitter of Q6

should be about .7 volts. Record the voltage here:

V(Q6) = ________.

Turn the power OFF. If your answer is greater than 2
volts, check R20, R21, R22, R24, Q6 and the battery.

Since the current through resistor R22 is equal to the
current through transistor Q6, calculate the current
through Q6 as follows:

Current (I) = V(Q6) / R22

Your calculated answer should be between .0005
amps (.5 milliamps) and .0011 amps (1.1 milliamps).

Current (I) = __________.

Connect your VOM as shown in Figure 28. Switch
the AM/FM switch to the FM position. Set your VOM
to read 9 volts DC. Turn the power ON. The voltage

at this point should be between 7 and 9 volts. Turn
the power OFF. If you do not get this reading, check
R25, C24 and the battery voltage.

FM VOLTAGE

TRANSISTOR CURRENT TEST

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