Elenco Projects 306-511 - Manual (Page 12)

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Project #316
OBJECTIVE: To build a working FM radio.
The FM module (FM) contains a scan (T) and a reset (R) button. The
R button resets the frequency to 88MHz. This is the beginning of the
FM range. Press the T button, the module scans for the next available
radio station.
Turn on the slide switch (S1) and press the R button. Now press the
T button and the FM module scans for an available radio station.
When a station is found, it locks on to it and you hear it on the speaker.
Press the T button again for the next radio station. The module will
scan up to 108MHz, the end of the FM band, and stop. You must then
press the reset (R) button to start at 88MHz again.
FM Radio
Project #317
OBJECTIVE: To build a complex circuit.
Note that there is a 3-snap wire between RV and U4, partially hidden
under R4.
This is an example of using many parts to create an unusual circuit.
Set the meter (M2) to the LOW (or 10mA) scale. Turn on the slide
switch (S1). As the circuit oscillates, the 7-segment display (D7)
flashes the number 5 and the LED’s (D1 & D2) flash as well. The
meter deflects back and forth and the speaker (SP) sounds a low tone
at the same rate. The frequency of the circuit can be changed by
adjusting the adjustable resistor (RV).
Next, place the 100 Ω resistor (R1) directly over the diode (D3) using a
1-snap. See how this changes the circuit performance.
Mega Circuit