A well tuned antenna system works like a dummy load, i. e. the SWR is 1. 2:1 or below but the hunting range is low. What`s wrong Insufficient radiation How to know that Yes, this is what the article about. You can measure the effective radiation using a field strength meter (FSM). A commercial FSM can measure the loss or gain of radiation, testin
Click here to download the full size of the above Circuit.
g polarisation, plot the radiation pattern for the various antennas for comparison. The cost for a commercial FSM can vary from Rs 1500/- to Rs 5000. But this design one can assemble for a few hundred. The Standard Analog Meters or LCD - DVM based FSM are some what DEAF and the meter level movement can`t be read from a distance of around 5 ft and above. To avoid this problem, this FSM is having a 10 level multi coloured 3mm LEDs for level reading; this will give a fair reading up to 20 ft + distance even at night. The FSM will give RF radiation reading; picked through the air, that shows an antenna`s gain of radiation. Due to this REAL READING, one can compare different types of antennas gain, angle of radiation, polarization etc. The FSM sniffs out bad coax, connectors or improperly grounded transmitter. It is a good instrument to plot radiation patterns of yagis / verticals. It is an educational tool for studies. SWR meter cannot do or detect some measurements about RF. But this FSM will do!. When Working with different types of input RF signal levels, the sensitivity of the NSH FSM can be controlled by changing different types of sensing antennas. Remember that, VSWR meter only shows that the antenna is fully loading and shows a low reflected power or very low SWR, but it does not mean that the antenna is efficiently radiating the TX power into AIR - The only tool that shows the exact on-air radiation levels is FSM....
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.....
characters left: