Data Sheet

385. More NOT Gate Applications
Build the circuit to the left. The lamp (76) lights and you will hear the
sound of a siren. Note that the siren sounds while the press switch (61)
is off, but when you press the press switch (61) the siren goes off. This
type of circuit could act like a mute button for the sound on your TV.
386. FM Radio
Build the circuit to the left, turn on the switch (62), and move the
magnet (7) near the reed switch (83) and you will hear some FM radio
stations from the speaker (93). You may have to press one of the press
switches (61) to get the FM receiver to scan for a channel. When you
press one of the press switches (61), the FM receiver will scan for
either a higher radio frequency (CH+) or a lower radio frequency (CH–).
For best FM reception, hold the open end of the spring wire (9) in the
air. The spring wire (9) is acting like an antenna in this circuit to receive
FM radio signals that are typically sent from high power antennas on
tall buildings in cities near you. You may nd that by putting your nger
on the pin on the loose end of the spring wire (9), you get even better
reception. This is because your body also acts as an antenna.
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