need FM circuit

[rupam91]

Hi frendzz. i am very new in electronics projects. recently made a fm transmitter which works fine in short range. now i want to make a fm receiver in the frequency range of 88-108 MHz but cant find a descent circuit diagram. plz help me with it guyz. i will do it on a breadboard and want to avoid ICs if possible. circuit with transistors will be good for me. thanks in advance.

 

[audioguru]

A breadboard has too much capacitance and inductance between its rows of contacts and the connecting wires for radio frequencies.
FM radio is a very high radio frequency.

Transistors were replaced by ICs in FM radios about 50 years ago.
Where will you get the coils and transformers to make an FM radio?

 

[alec_t]

There are many cheap FM radios coming out of China these days (e.g. available for £1 in the UK). One of those will cost much less than the components bought separately.

 

[rupam91]

Ok then i will use IC if it gives quality performane. Just advise me a proper circut diagram. I'm confused between the various circuits i got by searching. As an amature i dont know which will work good.
And alec_t, with ur point of view i even have to buy anything. Mobile phones have fm. But thats not the point, i want to build it by myself.

 

[audioguru]

Sony and other radio manufacturers made radio ICs a long time ago but not anymore.
I don't know where to buy a radio IC today.
Go to China and buy 10000 (the minimum order) radio ICs.
Hire a professional radio engineer to design a pcb for your circuit.

The FM radio at The Dollar Store has Horrible performance.

 

[absf]

As an amature i dont know which will work good.

Depends what you mean by "good". A decent FM radio normally has a Mixer stage which mixes the RF received with a frequency higher by 10.7MHz. The signal then passes through 2 stages of IF amplifiers and then goes through FM detector to be converted to Audio. I am not sure if you can get those OSC and IF coils in your local shops selling electronic components. They most properly came in as a set.

Here is a smple one using the philips TDA7000 FM chip and the LM386 audio amp. The whole radio only using one coil and you can wind it yourself. The PCB design was also given. But quality-wise.... I cannot tell as I've never done it before. So here's the link. Decide yourself...

http://www.escol.com.my/Projects/Project-01%28FM-Radio%29/Proj-01.html

http://www.escol.com.my/Projects/Project-01%28FM-Radio%29/PCB-Project%2001.pdf

Allen

 

[audioguru]

The antique Philips TDA7000 FM radio IC is obsolete and has not been made for many years. It had horrible performance. It was replaced by the TDA7088 FM radio IC with scanning which is also not made by Philips anymore but is made by a Chinese company for those terrible $1.00 radios.

I got a couple of those $1.00 radios for free by buying a newspaper. Strong local stations overload it and appear all across the dial. If the antenna is shortened then medium strength local stations are received with distortion and noise. Weak distant stations are not received.

 

[jjw]

Here has been used newer chip from Silicon Labs:
http://theradioboard.com/rb/viewtopic.php?t=3539

 

[audioguru]

Here has been used newer chip from Silicon Labs:
http://theradioboard.com/rb/viewtopic.php?t=3539

It appears to be a simple AM radio circuit.

 

[jjw]

It is FM/AM/SW chip
https://www.electro-tech-online.com/custompdfs/2013/05/Si4831-35-B30.pdf

 

[audioguru]

It is FM/AM/SW chip

Its spec's are fairly good and it is a very modern design.

 

[HiTech]

The purpose of this whole thread has me wondering... and laughing- sheesh!