Elenco Electronics AM/FM-108CK Assembly And Instruction Manual page 47

If you don't have an RF generator, skip to the RF Amplifier Assembly Procedure.
Generator
Hz
Connect the RF generator and VOM to the circuit as
shown in Figure 42. Set your VOM to read 9 volts DC.
Set your generator at 10.7MHz no modulation and
moderate signal strength output. Turn the power ON.
Record the voltage of D1 here:
V(D1) = ________.
While watching your VOM, slowly decrease the
frequency of your generator.
decreases, the voltage at D1 should increase. Increase
RF AMPLIFIER ASSEMBLY INSTRUCTIONS
R1 - 22kΩ Resistor
(red-red-orange-gold)
C3 - .001μF Discap (102)
C2 - .005μF Discap (502)
Q1 - 2N3904 Transistor
(see Figure C)
R2 - 6.8kΩ Resistor
(blue-gray-red-gold)
C4 - 470pF Discap (471)
TP15
As the frequency
.001μF
Figure 42
the frequency of the generator until the voltage is equal
to V(D1). While watching your VOM, increase the
frequency of your generator.
increases, the voltage at D1 should decrease. This
correction voltage is what keeps the oscillator from
drifting. If the voltage at D1 still does not change at D1,
check D1, R29, R30, C26 and C27. If these parts are
inserted correctly and the voltage at D1 still doesn't
change, then increase the amplitude of your generator
and repeat the same steps again. Turn the power OFF.
-46-
V
Amps COM V/Ω
TP15
As the frequency
L1 - FM RF Amp Coil
(6 Turns) see Figure N
L2 - FM RF Amp Coil
(2 Turns) see Figure N
C5 - 470pF Discap (471)
C6 - 33pF Discap (33)
R3 - 470Ω Resistor
(yellow-violet-brown-gold)
TP14 - Test Point Pin
(see Figure A)
Figure N