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| Author | Views | Views Today | Rank | Comments |
| 366,608 | 266 | |
350 |
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Here is the schematic, PC board pattern, and parts placement for a low powered FM transmitter. The range of the transmitter when running at 9V is about 300 feet. Running it from 12V increases the range to about 400 feet. This transmitter should not be used as a room or telephone bug. |
Schematic |
PC Board Layout and Parts Placement |
Parts |
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Notes |
Related Circuits |
Comments |
| In what frequency(channel) do this transmitter send information | ||
| Hello I am building a low power fm transmitter and I believe the last step I'm having trouble with is the inductor coil and making sure I have it correct does anybody have some good knowledge on inductors and how to make sure u have it correct? Thanks | ||
| bulit one but it does not work, i think the core part of it is the LC circuit, if the inductor or capaciotr value varies, the osillating freq can easily out of range between 88~108MHz | ||
| sine: The capacitor needs to have approximately the same range (e.g., 2-20, 5-15, ...) to stay in the same frequency band. If you stray from this range, you'll need to compensate by changing L2. Chris: If you can't read a schematic, you don't want to attempt this project. Start with something a bit simpler to get your experience level up a bit. It's easy build a ckt that won't tune into the FM band if you're not careful with layout, etc. Vinod: The capacitor between C and E is to provide feedback to make the circuit oscillate. | ||
| This should work fine. Download "LT Spice IV" amd you'll see it works just fine. I built this 35yrs ago and as kids we had a lot of fun (in the UK, the police band was just above the commercial FM band and this circuit tubes there too!), THe circuit I built then had a POT accross the microphone to adjust adio sensitivity - that may be needed here. I also reacall the circuit is very temperamental even when your hand comes close it stops (or starts) working. Play with that and tweek the coils, you'll get it working. Tomorrow I will build this with my 12 yr old son. | ||
| Sir l would like you to provide me an advise as how to set up an FM station with range of 70km.and also provide me with the sites where l can get a reasonable deal.Actually am looking for used equipments with computer. | ||
| hello dear iam live in ethiopia at the western waht ihave acommet is iwants to work atransmiter but i couldnt get the transister type like2n3866 the same as other can u support me how ican get it or equievalent pleas support me thak u | ||
| tempting to build one. But does it really work? I need to know cuz there's no point in building something that wont work in the first place. | ||
| Hey i am not very good with electronics but i would like you to send me a pic or something that shows me how to make a very easy FM transmitter, but not a diagram that says r1, r2, 10k resistor and all that stuff can you step me through what i have to get, what it looks like and where to put it | ||
| Guys plz help. I made this circuit and it didnt work. I didnt get the exact VC and wire. Please tell me is there any substitute for varicap and wire used. | ||
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