40w no tune amp

Posted on Feb 7, 2014

To boost the output power of low power FM broadcast band exciters, a number of these are available commercially, both as kits and ready made. See How to be a Community Radio Station for links to reviews of some of the more popular exciters. Unwanted spurious RF radiation, resulting in interference to other users of the electromagnetic spectrum, th

Click here to download the full size of the above Circuit.

us risking a visit from the state, and consequent risk of equipment confiscation, fines, and possibly imprisonment. I believe the quality of the vast majority of schematics and designs for FM broadcast equipment available on the internet to be far from satisfactorily. See my advice on building from plans on the web. In particular the information available on VHF RF power amplifiers is even more desperate, for example designs using dinosaurs of devices such as the TP9380. This design is based on a new MOSFET device, with the attendant advantages of Seeing as most of the designs on the web are over 10 years old, using a recently introduced device should maximise the useful life of the design. I also use this design as a vehicle to demonstrate the amount of information required for a third party not equipped with mind-reading skills to successfully build this amplifier. The point is this: if a person is sufficiently skilled and experienced to build something from scanty design information, for instance just a schematic, they are just as able to build it from no information at all. Conversely, a person not at that skill and experience level will require detailed instructions to succeed. The amplifier design is based on the recently introduced (1998) Motorola MRF171A MOSFET ( MRF171A data sheet in PDF format). Do not confuse this with the older, now discontinued, MRF171 device. January 2002 - Motorola changes their RF power...

Visit page

Leave Comment

characters left:

Related Circuits

LED Tester

You have to admit that these tiny electronic lamps are handy, and they last almost forever. Around 40 years after Nick Holanyak developed the first LED, they have become just about indispensable....

LED VU Meter

The circuit below uses two quad voltage comparators (LM339) to illuminate a series of 8 LEDs indicating volume level. Each of the 8 comparators is biased at increasing voltages set by the voltage...

Micro Power AM Broadcast Transmitter

In this circuit, a 74HC14 hex Schmitt trigger inverter is used as a square wave oscillator to drive a small signal transistor in a class C amplifier configuration. The oscillator frequency can be...

Moduler Preamplifier

To complement the 60 Watt MosFet Audio Amplifier a High Quality Preamplifier design was necessary. A discrete components topology, using and - 24V supply rails was chosen, keeping the transistor...

Plant Watering Watcher Circuit Schematic

This circuit is intended to signal when a plant needs water. A LED flashes at a low rate when the ground in the flower-pot is too dry, turning off when the moisture level is increasing. Adjusting...

Power-Off Time Delay Relay

The two circuits illustrate opening a relay contact a short time after the ignition or ligh switch is turned off. The capacitor is charged and the relay is closed when the voltage at the diode...

Pure Class-A Headphone Amplifier Schematic

The mentioned shunt-feedback configuration also allows the easy addition of frequency dependent networks in order to obtain an useful, unobtrusive, switchable Tilt control (optional). When SW1 is...

Quick On-Board Junction Tester

Short circuits or broken pcb tracks can be easily recognized by means of a Multimeter, but this tool can give wrong results when testing the efficiency of a transistor or diode, unless the device...

New Circuits

Zero consumption Anti-theft High power Code Switch for E-Bike Batteries

This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
Ultrasonic distance finder circuit

The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Simple Metal detector circuit with CD4030

Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Fully automatic watering circuit for flower pots

Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
Simple deep searching metal detector circuit

The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
Sub-Harmonic Bass Converter for Electric Guitars

The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
Echo Depth Sounding Sonar for Boats

In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
100W HiFi Audio Amplifier Circuit

This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
Plant-Pot Water Level Indicator Circuit

A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....