With the P1 we regulate the intensity of sound. With the P2 we regulate the frequency of reception. Optionally: If you want to check the frequency with your PC it will be supposed you make the following energies: You assemble and the circuit that is in the blue frame. You cut the driver dj'pla in point A, as it appears in the circuit and you connect points A,V. If you know some language of programming as C ++, PASCAL, VISUAL BASIC, DELPHI etc you can write a program which will send in the parallel door (378 I) of PC a number from 0 until 255 checking thus the tendency of expense of simple D/A of converter (that it is in blue frame) and consequently and frequency of radio via passage VARICAP.
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(As long as grows the number that sends in the parallel door, so much minimizes the frequency that receives the radio.)
Stabilised tendency of catering: Vcc=9~12V. Frequency of reception: 88~108MHz. Consumption: 100mA.
R6-r12=7,5K - Optionally,
R13-r21=15K - Optionally,
P1=10K Logarithmic potentiometer,
P2=100K Linear potentiometer,
C4, c14=220nF Polyester,
C7, c18=180pF Ceramic,
C10, c13=330pF Ceramic,
C12, c16=3300pF Ceramic,
C15, c17=1800pF Ceramic,
C19, c21, c22=10mF/16V electrolytic,
C24, c25=470mF/16V electrolytic,
L1, l2=5 Coils linked with internal diameter 4mm from cupreous isolated wire 0,6mm.,
IC1=TDA7000 with base DIL18,
IC3=LM386 with base DIL 8,
D1=BB329 or BB105 or other than old tuner televisions.,
S1=Switch of catering.,
AERIAL=50cm isolated wire,
CONNECTOR DB25=Fastener of 25 pin parallel door PC (LPT) -Optional.
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