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This circuit is a circuit diagram fm transmitter. Transmitter circuit described here has the additional RF power amplifier stage, after the oscillator stage, to increase the power output of 200-250 milliwatts. With a good matching 50-ohm ground plane antenna or multi-element yagi antenna, this transmitter can provide a good enough signal strength to a distance of about 2 kilometers.
Long Range FM Transmitter Circuit – [Link]
The antenna that comes with the 900 and 1300MHz video transmitters usually aren’t any good. In fact they are quite inefficient and due to bad design and build tolerances of certain crucial parts. You can however quite easily improve the efficiency and thus the range of these systems by using a tuned antenna. You can even quite easily build your own!
In this guide I will show how to make two designs.
DIY monopole antenna – [Link]
This project shows how to convert a simple FM transmitter to a miniature TV transmitter. Just change the input from the audio to the video (video camera or VCR) and check the signal at your television set. In Europe, for instance, choose the channel 2 – 4 and turn the trimmercap of the transmitter until you see a clear image.
Micro TV transmitter - [Link]
A relay sequencer is used in a radio transverter and is use to activate particular stages in order after short delay. This project describes how to build this sequencer. It has the following features.
- Four negative sinked delayed output so higher voltages can be switched.
- Adjustable delay (seconds to ms).
- Input / output switching for TX or RX IF stages from radio.
- Activation on PTT through +8VDC on the radio RF input or external +ve voltage control.50 ohm dummy load for radio RF signal.
- Adjustable RF level for TX IF stages.
- 12VDC operating voltage.
Relay Sequencer Board - [Link]
This FM transmitter (FM Tx) is about the simplest and most basic FM Tx it is possible to build and have a useful
transmitting range. It is surprisingly powerful despite its small component count and 3V operating voltage. It will
easily penetrate over three floors of an apartment building and go over 300 meters in the open air. The circuit
we use is based on a proven Australian design.
Simple FM Transmitter – [Link]
The 60 Watt linear amplifier is simple all solid state circuit using power mosfet IRF840. The IRF series of power transistors are available in various voltage and power ratings. A single IRF840 can handle maximum power output of 125 watts.
60W Linear amplifier – [Link]
This is a small but quite powerful FM transmitter having three RF stages incorporating an audio preamplifier for better modulation. t has an output power of 4 Watts and works off 12-18 VDC which makes it easily portable. It is the ideal project for the beginner who wishes to get started in the fascinating world of FM broadcasting and wants a good basic circuit to experiment with.
4 Watt FM Transmitter – [Link]
This is an excellent 50mW Hi-Fi PLL FM Stereo Transmitter that features BH1417 chip. ROHM’s new Japan has BH1417 is one of the most simple and practical integrated circuits, which combines phase-locked loop circuit, stereo encoder circuit, transmitter circuit, as well as other additions. Check schematic on the link below.
50mW BH1417 Stereo PLL FM Transmitter - [Link]
This Phone FM transmitter connects in series to your telephone line and transmits the telephone conversation over the FM band when you pick up the telephone handset. Transmitted signal can be tuned by any FM receiver. The circuit includes an “On Air” LED indicator and also provides a switch which can be used to turn off the transmitter.
Phone FM Transmitter - [Link]
There are two ways to learn PCB Trace Antenna Design. One is to go to the university the other is reading the article below! This article will guide you through “trial and error” approach to antenna design at the 2,4GHz communication band (wifi, zigbee, etc). The design procedure is clear enough and will help you save big time on your design.
The Dropout’s Guide to PCB Trace Antenna Design - [Link]
