3 transistor fm transmitter with coil on circuit board

3 transistor fm transmitter with coil on circuit board how to#
3 transistor fm transmitter with coil on circuit board install#
3 transistor fm transmitter with coil on circuit board Pc#

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How were the values of the FM transmitter determined? What is BS170? is this transistor and how this fm transmiter give best result? I get it stability to 50khz/5min and deviation to allmost 100khz. So after that I builded smaller versio of that using junk SMD parts and with little modifications. That little transmitter is very unstable, it drift 89.100 to 89.329, 229khz in 5mins! And FM deviation iss very slow, only about 5khz. I builded that transmitter to that PCB layout seen on that page. Please help me about this circuit,can i replace mic by audio jack ? This transmitter needs stable voltage, any voltage trop or rise changes the frequency

KN2222A looks like the 2N3904, soo i think that yes you can use that

3 transistor fm transmitter with coil on circuit board how to#

I'm a teacher in the high school & I'd like very much to put forward this project for the annual competition for my students.Ĭan you please tell me how to make a reciever of the same frequency as this tranmitter. I'd like to use the transmitter for remote switching.How to replace mic to send a switching pulse? I made a post on my blog and an instructable. I've searched for the website and was so glad that it's still up and running. I've tried it back in 2001 and it's just worked perfect. Is this FM transmitter available in kit form with all the part and PWB? It looks a lot better now!ģ Watt FM Transmitter, 8 Watt Audio Amp, 22 Watt Audio Amplifier, 50 Watt Amplifier, Crystal Radio, FM Transmitter, Guitar Fuzz Effect, FET Audio Mixer, Microphone Mixer, 8 Note Tune Player, Op Amp Radio, Mono To Stereo Synthesizer, Electronic Stethoscope, Tone Control, Transistor Organ, Stereo Tube Amplifier, Digital Volume Control, Sound Level Meter, Aircraft Radio Communications Receiver, Single Chip FM Radio, One Tube Regenerative Radio, Single Chip AM Radio

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An antenna may not be required for operation.

You may want to bypass the battery with a.

You can use 1/4 W resistors mounted vertically instead of 1/8 W resistors.

Q1 and Q2 can also be 2N3904 or something similar.

This transmitter operates on the normal broadcast frequencies (88-108MHz).

3 transistor fm transmitter with coil on circuit board install#

Remove the form after winding then install the coil on the circuit board, being careful not to bend it. The inside of a ballpoint pen works well (the plastic tube that holds the ink). L1 and L2 are 5 turns of 28 AWG enamel coated magnet wire wound with a inside diameter of about 4mm.

3 transistor fm transmitter with coil on circuit board Pc#

This transmitter should not be used as a room or telephone bug.ĩV Battery Snap, PC Board, Wire For Antenna Running it from 12V increases the range to about 400 feet. The range of the transmitter when running at 9V is about 300 feet. Here is the schematic, PC board pattern, and parts placement for a low powered FM transmitter.