3 transistor fm transmitter with coil on circuit board

3 TRANSISTOR FM TRANSMITTER WITH COIL ON CIRCUIT BOARD INSTALL
3 TRANSISTOR FM TRANSMITTER WITH COIL ON CIRCUIT BOARD DRIVER

I have a seperate module for this that generated a 2volt control sigggnal i assume conn this thru 30k resistor to varactor diode,may work,do you have any suggestions if this is feasable?. With box aux in & mic port.Just plug and play. I have already A fully welded kit with 7 to 10 km long range. Check with the local authorities.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

Local laws in some states, provinces or countries may prohibit the operation of this transmitter.

The other trimmers must be adjusted to maximum output power with minimum SWR and input current. Q1 and Q5 should be cooled with a heat sink.Build the transmitter in a RF-proof casing, use good connectors and cable, make a shielding between the different stages, and be aware of all the other RF rules of building. Make some connections between the two sides. The circuit has been tested on a normal RF-testing breadboard (with one side copper).Email Rae XL Tkacik with questions, comments, etc.Of 1 : 1.05 (quite normal at my place with my antenna).Ħ-hole Ferroxcube Wide band HF Choke (5 WDG)īB102 or equal (most varicaps with C = 2-20 pF will do) The notes that I made at the original schematic, it worked fine with a SWR In combination with the BLY88 amplifier to obtain 20 W output power. This is a circuit that I've build a few years ago for a friend, who used it Although the stability isn't so bad, a PLL can be used on this circuit. Output power that can be used between 90 and 110 MHz. use of this transmitter with outdoor antenna is illegal in most parts of the world.This is the schematic for an FM transmitter with 3 to 3.5 W Note: This transmitter is meant only for educational purposes. They have 4, 6, 6, 5 and 7 turns of wire, respectively.

3 TRANSISTOR FM TRANSMITTER WITH COIL ON CIRCUIT BOARD INSTALL

Install the antenna properly for maximum range.Ĭoils L1 through L5 are made with 20 SWG copper-enamelled wire wound over air-cores having 8mm diameter. Assemble the circuit on a general purpose PCB. You can also use a 12V battery to power the circuit. Regulator IC 78C09 provides stable 9V supply to the oscillator, so variation in the supply voltage will not affect the frequency generated. Also adjust trimmers VC2 through VC7 to get maximum output at maximum range. Carefully adjust trimmer VC1 connected across L1 to generate frequency within 88-108 MHz. Use a heat-sink with transistor 2N3866 for heat dissipation ( Note: or 2N4427 because it works better at 12 V and delivers up to 1 watt RF power). Signals are finally fed to the class-C RF power amplifier, which delivers RF power to a 50-ohm horizontal dipole or ground plane antenna.

3 TRANSISTOR FM TRANSMITTER WITH COIL ON CIRCUIT BOARD DRIVER

The preamplifier is a tuned class-A RF amplifier and the driver is a class-C amplifier. You can also use transistor 2N5109 in place of 2N2219. The FM signals are amplified by the VHF preamplifier and the pre-driver stage.

When you speak near the microphone, frequency-modulated signals are obtained at the collector of oscillator transistor T1.

Working of the 1 Watt transmitter circuit is simple. This FM transmitter circuit uses four radio frequency stages: a VHF oscillator built around transistor BF494 (T1), a preamplifier built around transistor BF200 (T2), a driver built around transistor 2N2219 (T3) and a power amplifier built around transistor 2N3866 (T4).Ī condenser microphone is connected at the input of the oscillator.

3 transistor fm transmitter with coil on circuit board