A fairly simple `divide-by-1000` circuit which was first designed by Zeljko Bozic, S52ZB, in a 2006 issue of VHF Communications Magazine. The idea of this project is to extend the range of older (and cheaper) frequency counters. You can often find 100 MHz frequency counters for as little as $20 at hamfests or eBay, and this simple circuit wi
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ll extend their range up to at least 13 GHz. This version is based around a Hittite HMC363 divide-by-8 prescaler, a Fujitsu MB506 divide-by-64 prescaler, and a "divide-by-1. 953125" circuit using standard digital logic. The Hittite HMC363 front-end prescaler is good up to 13 GHz or so, and will do 15 GHz if you increase the input RF power a bit and minimize the prescaler`s exposure time. It`s possible to pick up the Hittite HMC363 evaluation board for around $100, or you may be able to receive a couple HMC363s as free samples. The evaluation board will be ideal, as it`s properly designed for high-frequency microwave work. The Fujitsu MB506 can be found in some MMDS or satellite TV downconverters, the Fujitsu MB501 can probably be substituted with a slight circuit change. Fujitsu MB501 prescalers can be found in older analog cellular phones. The rest of the circuit is just a simple ECL-to-CMOS logic converter using a Maxim MAX961 high-speed comparator, and some 74HC390 ripple-counters and 74HC02 NOR-gate logic chips wired up as a divider. The output of the Fujitsu MB506 is in Emitter-Coupled Logic (ECL), which means the signal is 1. 6 volts peak-to-peak with a DC offset of around 3 volts. The Maxim MAX961 compares this signal to a preset reference DC voltage and converts the signal into one with the normal +5/0 volts that we`re used to. The "divide-by-1. 953125" circuit is based around the fact that by using three...
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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