Even though I'm a newbie, I don't mind it taking a while, so I will be able to spend lots of time fiddling with it if I choose this one. This one looks very good, but as you said, fairly complex. Apparently it's a pretty shoddy circuit and the guy who made the thread hasn't had much success(although the way he's not within 100km of an FM station probably didn't help.)Īfter some more searching, I have found a couple of transistor based superheterodyne receivers. Looking at that thread, it doesn't seem like such a good suggestion. In summary, is there any good designs for a superheterodyne FM receiver that isn't based on some sort of tricky-to-get-hold-of IC? Also, why might I not be able to build the one-transistor FM receiver on a breadboard or a PCB of my own design? Sorry if these aren't very clever questions, I don't have much experience with radio circuits, or huge amounts of experience with electronics for that matter. Why is this? Is this type of radio circuit very sensitive to circuit layout? Would it be impossible to build this circuit on a breadboard or prototype stripboard? I wanted to modify it so the output would be amplified by an op-amp to drive speakers or headphones. However, down at the bottom of the page it warns that unless you have a good experience with these type of circuits, that you should use the premade PCB that they offer. So, i continued searching and I found this design, which seemed quite good. However, I don't seem to be able to find any electronics store that stocks an IC like this - it seems very specialized. At first I was researching superheterodyne receivers which seemed quite interesting but the only circuits I was able to find where ones based on an IC instead of discrete components, like this one. I have been researching and have a reasonably good understanding of the principles behind it, and have found several circuit designs. Next part would be to add an RF amp and LO so that to achieve a stand alone working FM receiver and I feel pretty confident that that would be so simple actually!īelow is the current status on breadboard, and you can see the signal generator outputting 102.9MHz used for ~455KHz down-converting for the receiver.For an electronics project, I have been looking to build an FM radio. No tuned input circuits employed as of now and the whole circuit is powered using 3V(2xAA cells) Being connected with just a 5" antenna at the emitter of the transistor and Signal Generator output injected to the base in place of LO, let me say I'm quite surprised that the system could clearly receive couple of strong local FM stations nearby.įor 102.3MHz, I've injected around 102.9MHz to tune in the station clearly. So I've added a simple charge pump FM demodulator consisting of 2 BC547's and a BF494 wired before the IF stages as a simplest mixer. The next stage was to remove the oscillator/mixer and detector part from the working receiver to actually convert it to an FM receiver. This one was a big success and I could receive the local AM stations clearly and apparently I got surprised a bit on how beautiful is the so called 'superheterodyne' principle! A transistorized FM superhet receiver which can demodulate and output broadcast band FM stations.īut the interesting thing is that I have started with a basic Medium Wave receiver circuit with 455KHz two stage IF and basic germanium diode AM detector. I've carried out some quick experiments after the arrival of my new RF Signal generator/counter.
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