In electronics, a Lecher line or Lecher wires is a pair of parallel wires or rods that . Kundt’s tube experiment which is used to measure the wavelength of sound. The Lecher wire experiment found in undergraduate laboratories is usually limited to the observation of the voltage distribution for open and. I had this experiment in my Physics Waves and Optics lab, so I of the frequently asked questions for the experiment: Lecher Line(Wire).
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To really make this article shine, it would have been nice to go back and verify the measurements with some known standard. But if I HAD to…. The nodes are much sharper than the antinodes, because the change of voltage with distance along the line is maximum at the nodes, so they are used. You are commenting using your Facebook account. I wonder if this same effect would work even wwire the two Lecher wires were rxperiment connected at all- I think it might because presumably inductance is conveyed by light particles.
The high voltage of early transmitters excited a glow discharge in the gas.
Lecher line – Wikipedia
Then the distance from the end of wite link to the shorting bar is a half-wavelength. Two methods are employed to find the nodes.
Detecting really tiny current with a long filament, huge magnets, and some optics. Could be wrong, but I believe the wood right next to it will have a significant effect.
The wikipedia article has lechre good description of this phenomenon. One answer is to put away the oscilloscope and use the rest along with a length of wire instead.
An improved Lecher wire experiment
Looking for more high frequency measuring projects here on Hackaday? The Speed of Light. ,echer velocity depends on the dielectric. Given that the wires are surrounded by air, and that the relative permittivity of air is 1. I wonder how easy it would be to use a fluorescent tube and measure of light intensity. Email required Address never made public. The resulting data and graph are shown below. There was a 90 MHz signal of unknown origin that dominated and the induced signal from the oscillator was lower amplitude so it rode on the 90 MHz signal.
One difference between them is that transmission line stubs like Lecher lines also resonate at odd-number multiples of their fundamental resonant frequency, while lumped LC leched just have one resonant frequency. How do you test the oscillator circuit you just made that runs between MHz and MHz if all you have is a MHz oscilloscope, a few multimeters and a DC power supply?
The tuning necessary to select different stations is done by varactor diodes across the Lecher line. The oscillator is a voltage controlled oscillator. The end with the oscillator but pulled back from the Wore line.
Modern Views of Electricity, 3rd Ed. Its namesake is Ernst Lecher, a physicist from Austria who perfected the practice in R Jessop  uses a Lecher line anode tank. Lecher line, oscillator and other equipment.
An improved Lecher wire experiment – IOPscience
As I slide the bar along the wires, it influences the waves. Leave a Reply Cancel reply Enter your comment here Why does this so drastically differ from the values in the datasheet? How does it differ from the POS? Commercially available and ohm twin lead balanced ribbon feeder can be used as a fixed length Lecher line resonant stub. In the first photo above, the oscillator is pulled back a bit to make things clearer.
More fun discovering Lecher Lines though. Enhanced version and more background: The uniform spacing of the wires makes them a transmission lineconducting radio waves at a constant speed very close to the speed of light. An advanced treatise on alternating-current theory.
My favorite, though, expwriment wiring our ADC circuits experjment into the address bus through opto-isolators, of course of a Commodore 64 so that we could get data points every 10 ms when we wrote our apps in assembler. lechr
Using a Lecher Line To Measure High Frequency
So the line presents an impedance to the applied power which varies with its length; when a current node is located at the entrance to experimenf line, the current drawn from the source, measured by the ammeter, will expperiment minimum.
The length of the wires depends on the wavelength involved; lines used for measurement are generally several wavelengths long. Retrieved March 23, One end of the rods is connected to the source of RF power, such as the output of a radio transmitter.
Probably results will be more accurate if wires will be farther from wooden base.