Wiring Diagram Remote Control

This circuit provides an FM modulated signal with an output power of around 500mW. The input Mic preamp is built around a couple of 2N3904 transistors, audio gain limited by the 5k preset. The oscillator is a colpitts stage, frequency of oscillation governed by the tank circuit made from two 5pF capacitors and the inductor. ( Click here for Colpitt Oscillator Resonant Frequency Equation.) Frequency is around 100Mhz with values shown.

4 Transistor Transmitter Circuit Diagram

Audio modulation is fed into the tank circuit via the 5p capacitor, the 10k resistor and 1N4002 controlling the amount of modulation. The oscillator output is fed into the 3.9uH inductor which will have a high impedance at RF frequencies.

The output stage operates as a class D amplifier, no direct bias is applied but the RF signal developed across the 3.9uH inductor is sufficient to drive this stage. The emitter resistor and 1k base resistor prevent instability and thermal runaway in this stage.

This fm transmitter circuit is a very simple and require few external components and operates in FM band above 100 MHz.This fm transmitter needs to be powered from a 9 volts battery or from another 9 volts regulated power supply .The tuned coil L1, has two output tapping for the antenna connection, marked "A" and "B".

These are both low-level outputs and you choose which tapping you want to use ( stable low range, or more unstable but higher range). Tap B (2.5%) takes just a very small portion of signal from the oscillator circuit and therefore gives a very frequency stable transmitter. The output level (around 2.5mW) and range are therefore somewhat reduced.Tap A (10%) delivers very much more power (around 10mW) to the antenna load. This gives you a greater range, but at the expense of frequency stability. 

9V FM Transmitter Circuit diagram


All component leads should be kept as short as possible. The LINK wire on the PCB should lay flat on the PCB. Use the cutoff from a resistor leg.  Antenna length for circuit diagram transmitter varies with frequency for optimum distance: 90MHz 80 cm, 95MHz 75cm, 100MHz 70 cm, 105 MHz 68 cm.The frequency determining elements (L1, C5 and C6) form a simple LC tuned oscillator. The inherent problem with this type of circuit diagram transmitter is that any external load (antenna) will change the operating frequency.

Wireless FM transmitter circuit Microphone Hi Fi using a model-ready transmitters, this is because the buil-up transmitter module has a transmission capability of a stable and very effective to emit 10 mW RF. so that the target of Hi Fi FM Wireless Microphone transmitter circuit Hi Fi can be realized. The series can be seen from the FM transmitter Microphone Wireless Hi Fi transmitter module is that it stands alone with an additional R7, R8 and C6 to produce high-quality RF frequency.

In the series of FM transmitter Microphone Wireless Hi Fi module requires power consumption of a battery 12 VDC. Transmission antenna is directly connected with the circuit module Wireless FM transmitter Wireless FM Microphone Hi Fi.

A compact 2 transistor transmitter for use at VHF frequencies.

2 Transistor Transmitter Schematic Circuit Diagram

Notes:
Transistor T1 works as an audio preamplifier, gain is fixed at approximately R2/R1 or 100 times. The audio input is applied at the points LF in (on the diagram). P1 works as gain control. After amplification this audio signal now modulates the transmitter built around T2. Frequency is tunable using the trimmer CT and L1 is made using 3 turns of 1mm copper wire wound on a 5mm slug. The modulated signal passes via C6 to the antenna. A dipole can be made using 2 lengths of 65cm copper pipe. A DC power supply in the range 3 to 16 volts is required.

FM tracer was prepared using the LM3909 IC and some supporting components. 1.5V FM trackers This will provide an indicator of revenue sources by providing a signal emitted by the LED. FM tracking uses a source voltage of the battery cell and fruit consumption current is 3.7 mA.

Have been obtained if the working frequency Tracking FM 1.5V  (tracking transmitter) then the corresponding LED will light emitted by the transmitter information such as sound through an FM receiver is terdengan. 1.5V FM tracker (tracking transmitter) can use a regular 12-inch antenna. Playing and learning electronics that will be happy,

1.5 Volt Tracking FM circuit (Tracking Transmitter)

Circuit  Description 1.5 Volt Tracking FM (Tracking Transmitter)

AM Transmitter circuit 

To this powerful AM transmitters are huge, using ceramic tuning 3.587 mhz resonator and resonator filters are also sold with a value of 5.5 mhz, 7.7 mhz and 10.7 mhz. Distance transmitter range is approximately 2-4 km. the working principle of this circuit are filter resonator/ceramic filters raise the frequency of the value of the resonator filter.


This frequency is amplified by the transistor can be changed t1. Frequency so need C7 as a regulator / placement. sound signal superimposed over the audio transformer.frekuensi which awakened by resonator filters and t1 is fed to the next amplify strengthened so as to achieve the desired power passed to antenna. t2 and t3 as a buffer as a final power amp.

For AM radio because its hard to find IC ZN 414 then now could be replaced with the equivalent of IC MK 484. Frequency coverage between 550 kHz-1600 mhz, 3 pins of this IC include series of radio tuner, RF amplifiers, automatic gain control, the AM detector. The series voltage regulator or a power transistor made by BC 108B, 4diada IN 4148, 2k7, 820R, and the 10K trimpot, trimpot functions for selectivity of the controller of all series. Then we using a booster class A and class B amplifier for signal modulated not disappear.

Low pass filter is a circuit to filter freq dirty from an fm transmitter. so we get a clean signal. and can maximize the output power generated from the booster. low pass filter is capable to 150 watts. in this post . file [lay] that can only be opened with software sprint layout. for those interested please download here.