This circuit imitates the sound of wet bugs milling abouthe surface to attract
curious fish.
The circuit is basically aHartley audio oscillator operating in a frequency
between 200 and 2,006 Hertz. Powered by an AA cell, it can housed in a clean
empty peanut butter jar with the buzzer circuitry mounted upside-down on the
.ofti.Vou must be carefull not to drill in such a way as to allow water to leak
tnrougn the cap. silicon rubber can be used to close any water leak'
CapacitorCl would give a resonantfrequencyof approximately 1,000 Hz' but
p1 would give a wid6 variation in signaltone generated in the audio range'
You can also use a low-impedance earphone as a transducer, connecting it to
the second coil (output) of the transformer'
To operate, unscrew the cap, throw S1 ON, put the cover back on, and drop
the fish lure into the water in tne vicinity of where you will be fishing' Allow 20
minutes before reeling them in. lf necessary, adiust P1 to a new signal tone'
Figure I shows the schematic diagral for the Fish Lure. observe that the
se-condary coil of the small audio transformer is not used in this circuit.
construction details of the Electronic Fishing Lure, using a terminal strip as
chassis, is shown in Figute 2. The exact locations of components is not
critical.
T1 is also not critical. Any 500:8 or 1,000:8 transistor transformer with centertapped primary can be used. we can also suggest that any small transistor
transformer can be experimented with'
Parts List - Electronic Fishing Lure
Q1 - 8C548 general-purpose NPN silicon transistor
T1 - 500:8 or 1,000:8 transistor transformer
(RadioShack2TS-1380 is suitable for this task)
P1 - 100,000 ohm trimmer potentiometer
R1 - 1,000 ohm, 114W,5% resistor
C1 - 0.01 uF metal film or ceramic capacitor
S1 - SPST toggle or slide switch
BZ - Piezoelectric transducer or crystal earphone
(Radio Shack273-073 or equivalent)
81 - 1.5 V AA cell
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