2B-FM / AM RADIO RECEIVER
In the circuit of this project IC CXA1019S is used. With this IC you can listen the programme on FM / AM band. Only one transistor is used in the circuit. The programme of FM band in stereo mode are broadcast in clear sound. Therefore, you can fully enjoy the music in FM band.
IC CXA1019S is used in this prouject. This is a D.I.L. [Dual In Line] 30 pin IC. The pin no. 27 of this IC is given directly +4.5V supply to switch S1. Pin no. 1, 2, 12, 14, 19, 21, 29 & 30 are given negative supply. A sound section is also built inside the IC. The pin no. 5, 23, 25, 26 and 28 of IC CXA1019S work for the sound output section. A SPDT switch is used as a band switch. The pole of band switch is earthed. AM terminal of IC is connected with pin no. 16. The FM terminals are left open. In this receiver AM/FM gang is used. The central taping of volume control [10K] is connected with pin no. 5 of IC. One terminal of the side is connected with RF ground. Where as other side terminal is connected with ground. Pin no. 28 is the output pin of IC. The output signal in the speaker is given through a condensor 220mfd/10v with this pin. A ceremic filter CF 10.7MHz is connected between pin no. 15 and 18 of the IC. IC CXA11619BS can also be used in place of CXA1019S. But in that case you have to ground pin no. 2 and pin no. 1 of the IC is RF ground through a resistance of 1K. A ceremic filter [Xtal 10.7MHz] is earthed from pin no. 3 of the IC.
**PRECAUTIONS WHILE MAKING THE PROJECT
- Adjust the coil on ferrite rod for clear sound.
- Take care that there is no shortage on PCB while soldering the components.
- First of all, check all components so that all components are OK as per circuit.
- The tunning of IFT should be done carefully and with proper aligner.
- Solder the collector base and emitter of transistor carefully.
- Clean the terminal of all parts before soldering.