All about the famous Corsair and Commando Transmitters designed by Dave Martin of WNKR. This blog will show you how to make each of the transmitters and show you examples that other people have made for them selves. The circuit below is basically the first 2 stages of a Corsair, it must be noted that there is no low pass filter on the output. You s
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hould add one as even at these low powers harmonics can be a problem. A suitable filter will follow. The Transformer, AL21219 above, is from a PYE Westminister W15AM PMR set. It may be available from "Garex". As an alternative you may construct your own using a small transformer such as mains to 12v 1amp. Remove all the original winding and wind the primary with 80 turns of 24 SWG enamelled wire, this will be the audio side that connects to the TDA2003`s pin 4`s. The secondary winding is 180 turns of 22 SWG enamelled wire, A LM386 audio IC is used to series modulate Q2. The LM386`s output on pin 5, sits at half the supply voltage. But is swung plus and minus with the audio being fed to it`s input. In the high current version Q4 allows Q2 to draw more current without damaging the LM386. The PA, Q3, is a IRF530 which is configured as a linear amplifier. To set up you should, by adjusting RV2, set the DC voltage at TP1 to 2. 5 VDC. Then by moving the turns on L6 further apart or closer together, get the RF power to read 10 Watts. It must be noted that Q2, Q3 & Q4 must have heatsinks and that Q3 & Q4 should be mounted using a TO220 insulation kit.
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....
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....
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....
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....
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....
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,....
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....
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....
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.....
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