FM radio

TECHNICAL CHARACTERISTICS:

Stabilised tendency of catering: Vcc=9~12V

Frequency of reception: 88~108MHz

Consumption: 100mA

Materially:

The resistances are 1/4W.

R1

47K

R2

22K

R3

100K

R4

39K

R5

10

R6-r12

7,5K - Optionally

R13-r21

15K - Optionally

P1

10K Logarithmic potentiometer

P2

100K Linear potentiometer

C1

39pF Ceramic

C2

47pF Ceramic

C3

2,2nF Polyester

C4, c14

220nF Polyester

C5

22nF Polyester

C6

10nF Polyester

C7, c18

180pF Ceramic

C8

150pF Ceramic

C9

100nF Polyester

C10, c13

330pF Ceramic

C11

220pF Ceramic

C12, c16

3300pF Ceramic

C15, c17

1800pF Ceramic

C19, c21, c22

10mF/16V electrolytic

C20

10nF Polyester

C23

47nF Polyester

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

IC2

LM7805

IC3

LM386 with base DIL 8

D1

BB329 or BB105 or other than old tuner televisions.

SPEAKER

Loudspeaker 8W/1W.

S1

Switch of catering.

AERIAL

50cm isolated wire

CONNECTOR DB25

Fastener of 25 pin parallel door PC (LPT) -Optional

REGULATIONS:

A) With the P1 we regulate the intensity of sound.

B) With the P2 we regulate the frequency of reception.

C) 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 planning as C ++, PASCAL, VISUAL BASIC, DELPHI etc you can write some 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.

(As long as grows the number that sends in the parallel door, so much minimizes the frequency that receives the radio.)

Note:

Exists a simple program in DOS which I can to you him send in order to experiment. [kkontak@hotmail.com].

Also check the conversation about this project at the community. Post you questions here.

Title: FM radio
electronic circuit
Source: www.electronics-lab.com
Published on: 2005-02-03
Reads: 2719
Print version: Print version

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