FM and AM receiver

Thread Starter

brahms

Joined May 9, 2014
32
Hi guys, i'm wondering if anyone here can give me a working schematic or a link where i can find a working circuit of FM and AM receivers.. The simpler the better. Been searching and have done some that i have seen in the net but it's all faulty..

Thanks in advance!
 
Last edited:

MrChips

Joined Oct 2, 2009
30,621
You want a simple radio circuit?
Then you would't find both AM and FM together unless it is a commercial chip.

For a simple AM radio, try this:

 

takao21203

Joined Apr 28, 2012
3,702
I have built AM and FM transmitters from web schematics, yes, they are often incorrect, dont incllude component values, or need transistor types you dont have.

With some research it is possible to make them working, for instance there is often no adjustable resistor in the emiiter path, which you need by all means for two reasons:

-the hFE is incorrect, you get too much gain or not enough. Maybe the original author just tried until he found a working transistor, and then just wrote the type number.

-you use a substitute transistor, which normally should work, but the circuit is too much specific, so without changing the offset, the transmitter or receiver simply does not work.
 

alfacliff

Joined Dec 13, 2013
2,458
building an fm radio is more dificult than an am radio, the higher frequencies make lead lengths more critical and much more. there are lots of information on proper parts layout and fabrication in the ARRl amatur radio hamdbook or the RSGB handbook. actual hints from people who have been building ricievers and transmitters for a long time.
 
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