another way of getting bandspread for your favorite frequencies. Finally, it may be necessary to operate the counter on battery power only; connection of an AC adapter might introduce considerable hum into the receiver.
THE LM386 AUDIO OUTPUT:
As already mentioned the LM386 is certainly capable of far more audio power output than is given in this basic receiver circuit. It can only boost what it gets directly from the SA602. There is certainly space on the
The following is an audio preamplifier idea submitted by one of our customers. Ramsey Electronics in no way warrants that this modification will achieve any particular ideal
This modification requires cutting the circuit trace leading from C8 to the volume control, R3
27
pF
NE60
2
PIN
71 MEGOH
Additional LM386 used as AF preamplifier between U1 and U2:
Pins 1,7,8: not used
Pins 2,4: to ground
Pin 3 to
pin 5 to ‘+’ side of new 1 to 10µF capacitor
Pin 6 to ‘+’ DC supply board trace
TO
COUNT
ER