Figure 1 shows the 10. 58 to 10. 74 MHz VFO oscillator circuit. Yes, this is the same circuit that was presented last, but I`ve re-designed to show the Colpitts oscillator more clearly. `L` is approximately 1. 5 uh, 19 becomes a core T50-6 (yellow). The value of C6 is found experimentally. I 69 pF (47 pF to 22 pF and a parallel). More information abo
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ut this during check-out. "L" and the VVC with C6 form the parallel-tuned circuit that determines the frequency of the VFO. The CVV is a MV2104. Capacitors marked with an asterisk are required Silvered Mica, COG or NPO. You might wonder how the component values for the resonance circuit is determined. Well, when Jupiter aligns with Mars and Mercury on the cusp of the new moon, if the inductive reactance equals the capacitive reactance, then we have a resonance circuit. For a given frequency there are infinite combinations of L and C is a resonance circuit. Experience shows that the variable capacitors and VVC in the range of 5 to 300 pF pF are quite practical. Combine this with the fact that UH 1. 5 coil and a capacitor of 150 pF resonate near the frequency of interest, and has the component values for the resonance circuit this VFO. You can find the formulas to calculate all this in your manual if you like to do arithmetic. The values of the components actually used in the circuit to take into account "stray" inductance and capacitance that occurs in the real world. More information about this during check-out. Resonant circuits are fascinating creatures! Although I did not go into a theoretical discussion, there are some fundamental characteristics of resonant circuits that you (and me) should be considered in the construction of VFO, filters, amplifiers, etc. There are two types of resonant circuits commonly used are the...
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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