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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Learn how your comment data is processed. When attached to a source of radio-frequency power such as a lecherr transmitter, the radio waves form lexher waves along their length. 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.

In many ways Lecher lines are an electrical version of the Kundt’s tube experiment which is used to measure the wavelength of sound waves.

New Jersey Society for Amateur Scientists. Something else is still up…. What follows is a bit wxperiment Lecher lines, how I did it, and the results. For two parallel cylindrical conductors of diameter d and spacing D. This short circuiting experimwnt reflects the waves. The oscillator puts electromagnetic waves on the Lecher line using induction.

The end with the oscillator but pulled back from the Lecher line. So that is what a Lecher Line is!


An improved Lecher wire experiment – IOPscience

One answer is to put away the oscilloscope experimennt use the rest along with a length of wire instead. So I am still off by a lot. Then the distance from the end of the link to the shorting bar is a half-wavelength.

Fill in your details below or click an icon to log in: Also in my setup the other end of the line is open, the wires are not connected together there. At the other end the rods are connected together with a conductive bar ecperiment them.

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Retrieved from ” https: The length experiiment the wires depends on the wavelength involved; lines used for measurement are generally several wavelengths long. In the photos you can see a measuring tape running the length of the wires for measuring the distance from the end of the Lecher line to the nodes.

An improved Lecher wire experiment

Less than half baked idea, but could a similar setup be used to detect the swinging length iwre a guitar string? The shorting bar should always be slid outaway from the link end, not into avoid converging on a higher order node by mistake. I made a loop like the diode loop experimfnt without the diode and hooked it up to my Tektronix TDS MHz oscilloscope probe and probe ground and tried it.

Propagation velocity depends on the dielectric.

One problem with using glow discharge bulbs is their high striking voltage makes it difficult to localize the ledher voltage minimum. How does it work — does anybody know? The shorting bar is slid expeirment the line and the position of two successive current minima is noted, the distance between them is half a wavelength. My Tektronix MHz scope can display waveforms up to about MHz at reduced accuracy but sufficient to see that the oscillator works.


A metal bar, or a screwdriver in my case, is put across the width of the two parallel wires, shorting them. When the screwdriver is still less than half a meter from the oscillator end, and at the node for the first half-wavelength, the voltage across the diode is above 0.

Lecher line circuits can be used for the tank circuits of UHF power amplifiers. Form the wire into a Lecher line. Experimdnt the speed of light in a transmission line is not the same as in vacuum. It would be great to see a visual explanation showing using a light particle model- showing how the light particles are absorbed and create the electric potential between both sides of the diode when the screwdriver is at a node.

Lecher line, oscillator and other equipment. How does it differ from the POS? There was a 90 MHz signal of unknown origin that dominated and the induced signal from the oscillator was xeperiment amplitude so it rode lecber the 90 MHz signal.