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Showing posts with label fm. Show all posts

Tuesday, November 4, 2014

Small Single Chip FM Transmitter Circuit Schematic Diagram

The following circuit schematic diagram is the one used for the monophonic FM Transmitter. It is pretty clear seen on the circuit’s schematic that the left and the right signal is mixed before modulate the radio frequency.

Maxim Semiconductor’s MAX2606 is the core of this circuit. It is an integrated circuit which is compact, high-performance intermediate frequency voltage controlled oscillators. The output from this circuit is -21 dBm radiation power, and work with 3 volts power supply, so two small batteries with 1.5 volts each should be enough. You just only need a potentiometer to tune in the frequency within commercial FM broadcast band 88-108 MHz. And that is the best part. The frequency tuning circuitry have been handled by the IC, so you don’t need to bother. External varactor even doesn’t need in this circuit. One of the application that can be used with this circuit, you can extend your mp3/CD player in your room to your portable set around the house. Much more simple than using wires.

Wednesday, October 15, 2014

Build a 9V Wireless Microphone FM Transmitter

This FM transmitter circuit can be used as a wireless microphone, can be received by an ordinary 88- to 108-MHz FM broadcast receiver. For the power supply, this transmitter circuit is powered by a 9 V battery. To comply with the radiation limit of FCC rules, keep the antenna length under 12 inches. L1 is 6 turns of #24 wire wound around a pencil or a 1/4″ form, with turns spacing of 1 wire diameter. C6 is a gimmick capacitor which has value about 1 pF.

9V Wireless Microphone FM Transmitter Circuit Diagram

Thursday, September 25, 2014

FM Radio Receiver Antenna Booster Circuit

This affordable FM radio receiver antenna enhancer makes use of the BF324 TO92 type pnp transistor in a grounded-base arrangement.
The circuit can be utilized like a signal booster with VHF receivers whose front end is afflicted with reduced level of sensitivity (like a lot of valved and army supplemental variations). The frequency selection of the preamplifier is approximately from 75MHz to 150MHz.

The 2 inductors in the circuit are do-it-yourself. L1 includes 10 turns of 24SWG enameled copper wire; the inner dimension is 3mm, without any core. Inductor L2 bears 13 flips of the identical wire, as well as an inner diameter of 5mm; without core as above. A building tip: tight-wind the inductors making use of three and 5mm drill bits respectively in the form of momentary cores.

The prototype of the preamplifier was effectively tried with an 88-108 MHz FM broadcast receiver along with a 2-metre VHF ham receiver. The preamplifier consumes around 2.5mA from a 5-volt supply.

Sunday, September 7, 2014

TDA7012T Single chip FM received

FM Radio Receiver IC TDA 7012T is very simple, but Radio This FM receiver has good sensitivity and selectivity. Single Chip TDA 7012T FM Receifer is to build an FM receiver requires a few additional components.

Thursday, September 4, 2014

Stereo FM Transmitter 88 108 MHz based BA1404

This is the stereo FM transmitter schematic diagram which built based BA1404. By using this HI-FI stereo FM transmitter, you will be able to transmit MP3 music from your iPod, computer, discman, walkman, TV / SAT receiver, and many other audio sources.

The transmitter can work from a single 1.5V cell battery and provide excellent crystal clear stereo sound. It can also be supplied from two 1.5V battery cells to provide the maximum range.

The kits of Stereo FM Transmitter 88-108 MHz based BA1404 available at electronics-diy.com, check it out

Thursday, August 21, 2014

Stereo PLL FM Transmitter based BH1417

Here the schema diagram of stereo PLL FM transmitter based BH1417 chip. This is certainly the most recent BH1417 FM Transmitter design diagram from RHOM that consists of lots of capabilities in a single tiny package. It includes pre-emphasis, limiter to ensure that the music can be transmitted at the same audio level, stereo encoder for stereo transmission, low pass filter that blocks any audio signals above 15KHz to avoid any RF interference, PLL schema that delivers rock solid frequency transmission (no extra frequency drift), FM oscillator and RF output buffer.

There is certainly 14 possible transmission frequencies with 200KHz increments that you can select using a 4-DIP switch. Lower band frequencies begin from 88.7 up to 89.9 MHz, and upper band frequencies begin from 107.7 up to 108.9 MHz.

BH1417 could be supplied with 4 - 6 voltage and needs only about 30mA, giving 20mW output RF power. BH1417 delivers 40dB channel separation that is fairly good, although older BA1404 FM Transmitter chip delivers slightly better 45dB channel separation.

BH1417 is only offered in SOP22 IC case so this may possibly be an inconvenience for some people. On the other hand, since the chip is smaller than common DIP-based ICs its possible to fit the whole transmitter on a compact PCB.

BH1417 chip may possibly also be applied a stand alone stereo encoder. The benefit of thats that you have full freedom of working with a transmitter and amplifier of your choice. You will still have a pre-emphasis, limiter, stereo encoder and low pass filter in a single tiny package since very few external components are required for these blocks. PIN 5 is MPX output that could be directly connected to an external FM transmitter through a 10uF capacitor.

Detailed information about this schema, visit: http://electronics-diy.com/BH1417_PLL_Stereo_FM_Transmitter.php . The kit of stereo PLL FM transmitter based BH1417 also available there.

One Transistor FM Radio

Thi schema is very simple with only one transistor. No need additional active components, but if you want to hear the sound louder, just build another amplifier schema... :)

One

Part designator	Part description
C1a,C1b	10 pf, 50 v, ceramic disc capacitor
C2	22 pf, 50 v, ceramic disc capacitor
C3	RF tuning capacitor
C4	330 pf, 50 v, ceramic disc capacitor
C5,C8	0.001 uf, 50 v, ceramic disc capacitor
C6	0.22 uf, 50 v, film capacitor
C7	0.0047 uf, 50 v, ceramic disc capacitor
C9	22 uf, 16 v, electrolytic capacitor
D1	TL431AIZ voltage control Zener (shunt regulator)
EPH1	High impedance earphone
L2	22 uh RF choke
Q1	2N4416A JFET transistor
R1	470K, 1/4 w, resistor
R2, R3	1K, 1/4 w, resistor
R4	10K, 1/4 w, resistor
R5	1M, 1/4 w, resistor
R6	100 ohm, 1/4 w, resistor
S1	Small SPST switch
screws for C3	screws for mounting C3 (2 needed)
nylon screw	#4 nylon screw used for tuning C3
battery connector	mini battery snap

More instruction how to build this schema, visit this page