A. In electronics, a Lecher line or Lecher wires is a pair of parallel wires or rods that were used to measure the wavelength of radio waves. The Lecher wire experiment found in undergraduate laboratories is usually limited to the observation of the voltage distribution for open and short circuit. An improved Lecher wire experiment. To cite this article: M B Allenson et al Phys. Educ. 8 View the article online for updates and enhancements.

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Newnes Guide to Television and Video Technology. A Lecher line consists of two parallel wires or rods that form a balanced transmission line. Permission Reusing this file.

This page was last edited on 22 Novemberat The wikipedia article has a good description of this phenomenon. As shown in the above photos, I added the diode loop to the collection of loops at the end of the Lecher lefher.

Views Read Edit View history. Its namesake is Ernst Lecher, a physicist from Austria who perfected the practice in Retrieved March 24, 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 circuits just have one resonant frequency. Leave a Wir Cancel reply Enter your comment here Lecher wire demonstration apparatus with lamp for indicating the point of resonance.

The oscillator is a voltage controlled oscillator. My Tektronix MHz scope can display waveforms up to about MHz at reduced accuracy but sufficient to see that the oscillator works. But if I HAD to…. Graph of the data.


The loop is only around 3. There seems to be something to that. So that is what a Lecher Line is! So I am still off by a lot.

Lecher line – Wikipedia

The Electrical Engineer, Ltd. Plain Lecher line and with lecheer equipment in use The end with a loop A Lecher line consists of two parallel wires or rods that form a balanced transmission line. 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.

How does it differ from the POS? Learn how your comment data is processed. Could be wrong, but I believe the wood right next to it will have a significant effect. Also available on Arthur H. In many ways Lecher lines are an electrical version of the Kundt’s tube experiment which is used to measure lechre wavelength of sound waves. A Lecher line is a pair of parallel uninsulated wires or rods held a precise distance apart. Austrian physicist Ernst Lecherimproving on techniques used by Oliver Lodge [3] and Heinrich Hertz[4] developed this method of measuring wavelength around Radar circuit analysis by United States.

Lecher line

Does that make sense? Retrieved March 26, from D. The separation between the Wier bars does not affect the position of the standing waves on the line, but it does determine the characteristic impedancewhich can be important for matching the line to the source of the radio frequency energy for efficient power transfer. Then the distance from the end of the link to the shorting bar is a half-wavelength.


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 the line, the current drawn from the source, measured by the ammeter, will be minimum.

Commercially available and ohm twin lead balanced ribbon feeder can be used as a fixed length Lecher line lecyer stub. One answer is to put away the oscilloscope and use the rest along with a length of wire instead. Short lengths of Lecher line are often used as high Q resonant circuitstermed resonant stubs.

Lecher line circuits can be used for the tank eire of UHF power amplifiers.

Lecher wire wavemeter

The timestamp is only as accurate as the clock in the camera, and it may be completely wrong. One end of the rods is connected to the source of RF power, such as the output of a radio transmitter.

This reminds me of the fun part of physics classes. Lecher line, oscillator and other equipment. More fun discovering Lecher Lines though. The shorting bar is slid down the line and the position of two successive current minima is noted, the distance between them is half a wavelength.