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Yaesu G-400 Antenna Rotator Controller
A very simple controller circuit, with fairly smart performance! Can`t afford a fully automatic computer controlled rotator, but would like more capability from your basic rotator Would you like a simple to use "point and shoot" computer controlled antenna You`ve come to the right place! The ZL1BPU Rotator Controller has been designed as an...
Active ferrite rod antenna for HF
The red connector is for an optional external antenna wire and the black connector is for a ground wire. The red is wired to secondary winding and the black is connected to the circuit ground plane. Additionally two by-pass capacitors (100n) are soldered from different +9V locations to the GND plane for stability in high gain setting. The ferrite
Design of a wideband multi-standard antenna switch for wireless communication devices
Wireless smart sensor with small spiral antenna on Si-substrate
TV antenna principle circuit
Active Antenna for HF-VHF-UHF
Antenna Booster for FM AM and SW Receiver
This AM/FM antenna booster circuit amplify the broadband signal from antenna. This antenna booster should work fro FM, AM, and SW receivers. Here is the..
Crystal Radio Antenna Preamplifier
Adapting one of my failed Tesla coils into a crystal radio set to show the neighborhood kids. I`ve run into the #1 problem everyone faces not enough antenna to generate a strong signal. I read somewhere that a proper AM antenna should be between 100 500 ft for good reception (technically known as quarter wavelength). I don`t think anyone...
Low Frequency Antennas
Home-made antennas can greatly improve the performance of AM and FM radios, short-wave receivers, and scanners. If you are a talk-radio fan then experiment with the AM band antennas and you will be able to hear shows from all over the country with surprising clarity. Short-wave receivers are always coping with weak signals and they must have a...
The VHF antenna switch
Finally I have found a use for a bunch of DIP-style RF relays I acquired in a grab-bag from a discount electronics shop some time ago. These babies are sealed totally, and rf shielded with low contact capacitance. Perfect for VHF frequencies. They are 12 volt and have a fairly decent coil resistance, although I wish they were latching style. I hav
An B3CKS beer can VLF Antenna
So there is a chance to use them in combination with a condenser microphone amplifier for a VLF Receiver. Bingo. The first tests as a Monopole gave good results. I live in a small town located at J041VG with approximately 7500 inhabitants. The height above sea level is between 220-650 m over NN. My QTH is in the middle of town and 330 m over NN.
antenna tuner circuits
The Johnson 275 watt and Kilowatt Matchboxes are both unnecessarily exaggerated and unnecessarily maligned. They are not exceptional tuners, and are not poor designs. The primary drawbacks are the fixed coupling link, and the fact they are balanced VOLTAGE sources, not the generally more ideal current source. C2 is special and expensive. C2 is a d
Analog HF Antenna Analyser
Results are shown on an analog VSWR meter. The design was originally published in `Break-In`, New Zealand`s amateur radio magazine in Sept/Oct 2005, and is republished here with the permission of the editor. Note: `Break-In` is a term used in amateur radio to describe a system which allows another person`s signal to be heard in the brief
Digital HF Antenna Analyser
This instrument measures complex impedance over the 1. 6 - 33 MHz HF spectrum. It also calculates and displays the VSWR of the impedance referenced to 50 ohms. The most common application of the meter is as an antenna analyser. The design was published in `Break-In`, New Zealand`s amateur radio magazine in Jan/Feb 2006, and is republished here with
Wideband DTV UHF Antenna TV Amplifier Circuit using transistor 2sc3358
This HD TV UHF wideband amplifier (Ultra High Frequency amplifier ) has a total gain of 10 to 15 dB in the 400 850 MHz domain frequency so it can be used where the tv signal is weak. For this UHF antenna tv amplifier to work correctly you need to cut the components pins as short as possible. C1, C2, C6, C7 are SMD type ( surface mounted ). Thi
circuit to test servo motor (pole rotor) of parabolic antenna
That circuit is to test the motor servant of the parabolic antenna it is working perfectly, although a system with lnbf is much more appropriate, a lot of people they still use systems using lnb and servo motor. Then the idea of that circuit is to help to the technician reparation of parabolic antennas when doing test of operation of the servo mot
Active Antenna Circuits
Antenna Tuner Circuits
Yagi Uda Antennas
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 measured. There are three main categories of distance measurement methods in use: a) By...
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 find something potentially valuable, hidden a few centimeters below the soil. So many...
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 circuit comes as a solution to this problem. Depending on humidity of the pot at...
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 circuit of this metal detector, it is possible to detect a metal coin in depth of 90 to...
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, such as filtering or distortion. Instead, a frequency division system produces outputs...
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 calibration of the rope. This arrangement still exists in some yachts. The big...
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 supply must be symmetrical so that no electrolytic capacitors are needed at the outlet....
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. The circuit of the device is shown in Figure 2. The water detection is made from the bottom...
Analogue Sound Preasure dB-Meter Circuit
The best human ear can capture sounds from 20Hz to 20KHz. These limits are known to be the broadest that can exist. Normally the normal limits range from 100Hz to about 13KHz and depend on the age and health of the individual. We for our measurements and to have a good accuracy we will get the limits of 20Hz to 20KHz. A sound to be heard does...
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