Easy FM Radio Utilizing TBA120S

It is a easy FM radio utilizing a preferred TBA120S (14-pin). Most FM radio works on 10.7MHz IF frequency however this one does work on 5.5MHz IF frequency. So, the parts just like the 5.5MHz ceramic filter, and 5.5MHz IFT coil used for this FM radio will be simply discovered out there at a really low-cost. Additionally, an IC TBA120S used on this circuit will be simply discovered out there at a very-low price or you’ll be able to take off out of your outdated Black & White TV receiver set and so on.

Circuit Working

The circuit could be very easy. An IC1 TBA120S and Q1 (BF494) had been the center of this FM radio. A number of passive parts and Inductor L1 trimmer capacitor VC1 (2-22pF), X1(10.7MHz ceramic filter) and T1 (5.5MHz IFT coil) had been used on this circuit of FM radio.

Resistor R1 (470K) is linked between a base pin of Q1 (BF 494) and +6Volts. Resistor R2 (470) is linked between the emitter pin of Q1 (BF494) and the bottom.

Resistor R3 (680) is linked between pins 13 and 14 of IC1 (TBA120S). R4 (100) is linked to pin 11 of IC1 and to a +6V terminal.

Capacitor C1 (.001uF) is linked to an antenna (75cm lengthy) and to baseQ1 (BF494).C2 (.01uF) is linked between a base of a Q1 (BF494) and to a floor. C3 (10pF) is linked between the emitter and collector of Q1 (BF494). An output (pin 3) of X1 (5.5MHz ceramic filter) is linked to a pin 14 of IC1 (TBA120S). A 5.5MHz IF frequency is taken off from an emitter of Q1 (B494) and to a pin14 of IC1 (TBA120S) with a capacitor C4 (33pF). Pin no 2 of X1 is a connector to the bottom.

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Capacitor C5 (103) is linked between pin 13 and pin 12 and to a floor terminal. Capacitor C6 (103) is linked between +6V and floor. Capacitor C7 (103) is linked between pin2 and 13 of IC1.

C8 (103) is linked between pin 8 and pin 11 of IC1. A 5.5MHz IFT coil is linked between pin 7 and pin 9 of IC1. An AF output sign is taken out from pin 8 of IC1 (TBA120s) by means of an electrolytic capacitor C9 (22uF/25V). Pins 1,3 and 4 are linked to the bottom terminal.

Development and testing

You’ll require a 5cm*7cm Vero board for making your TBA120S FM radio. It’s possible you’ll use a PCB board as given within the article.

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To start with take a 14-pin IC socket and put it on the center of your vero board. Take a low-watt soldering iron and gently solder a 14-pin IC on the center of a vero board.

Now insert an NPN transistor Q1 (BF494) on the left facet of a vero board. Now insert all of the remaining parts like 5.5MHz IFT coil, resistors, capacitors or 5.5MHz ceramic filter and likewise solder all of them.

Subsequent, we’ll check a completed FM radio. You’ll want a 5.5MHz sign generator. Join a + 6V energy to your FM radio and join the AF output sign to an AF amplifier enter. Flip ON your 5.5 MHz sign generator and convey a 5.5MHz sign generator close to your FM radio. You’ll hear an AF tone popping out from a speaker of AF amplifier.

Subsequent, join a 75 cm wire to an antenna terminal. Slowly tune VC1 with a plastic screwdriver till you obtain a sign. You may additionally tune your FM radio by squeezing coil L1 (5 turns of 23 SWG wire on a 5 mm air core).

Now you’ll hear a station out of your FM radio. Lastly, take a plastic screw and gently tune a 5.5MHz IFT coil till you’ll hear a transparent sound out of your FM radio. So, take pleasure in listening to FM radio.

Elements Checklist