The amplifier can be used in a number of projects to buffer and amplify outputs from devices such as Direct Digital Synthesizer (DDS) chips. The board was initially produced to amplify the output of the 9833 DDS chip. The board was also intended for Amateur Radio applications (e. g. , a buffer amplifier for a VFO). Photo 1 shows the bare board and a
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board populated with all components except the optional output filter network. The board shown uses a bifilar wound 4:1 output transformer (as shown on the schematic and mentioned below). Schematic 1 shows the RF-Amp circuitry and a typical configuration of the optional output network. Note: with the given filter network, frequencies above 10 MHz are greatly attenuated. The schematic shows the board`s component layout, circuitry and connection points. The amplifier provides a voltage gain of approximately 16 to 18 dB. Photo 2 shows a gain vs. frequency plot of the basic amplifier board with an output optimized for the 3-10 MHz range (2000 Ohm load). Shown on this plot are the results for three different transformer windings, as follows: Photo 3 shows a gain vs. load plot of the basic amplifier board for the three windings given above. These plots show that the output impedance of the amplifier is approximately 220 Ohms without the 4:1 winding. With the impedance transformer, the output impedance is reduced to approximately 150 Ohms. The reduction over the 12 turn transformer is not 4:1 probably because the differences between the collector impedances for the two different transformers; the collector loading for the two transformers is comparable, but not exact. With the 4:1 transformer, a 2000 Ohm load and a frequency of 6 MHz, the voltage ratio between the collector and secondary of the transformer was (4220 mV rms)/(2210...
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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