This can be 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 elements just like the 5.5MHz ceramic filter, and 5.5MHz IFT coil used for this FM radio may be simply discovered out there at a really low-cost. Additionally, an IC TBA120S used on this circuit may be simply discovered out there at a very-low price or you possibly can take off out of your outdated Black & White TV receiver set and so on.

Circuit Working

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

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

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

Capacitor C1 (.001uF) is related to an antenna (75cm lengthy) and to baseQ1 (BF494).C2 (.01uF) is related between a base of a Q1 (BF494) and to a floor. C3 (10pF) is related between the emitter and collector of Q1 (BF494). An output (pin 3) of X1 (5.5MHz ceramic filter) is related 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 related between pin 13 and pin 12 and to a floor terminal. Capacitor C6 (103) is related between +6V and floor. Capacitor C7 (103) is related between pin2 and 13 of IC1.

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

Building and testing

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

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To begin 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 elements like 5.5MHz IFT coil, resistors, capacitors or 5.5MHz ceramic filter and in addition solder all of them.

Subsequent, we’ll take a look at 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, get pleasure from listening to FM radio.

Components Listing