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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Lecher line circuits can be used for the tank circuits of UHF power amplifiers.
By using our website and services, you expressly agree to the placement of our performance, functionality and advertising cookies. A simpler design is a “U”-shaped metal bar, marked with graduations, with a sliding shorting bar. Retrieved March 23, Apparently the screwdriver causes a reflection creating a standing wave of voltage and current on the line.
The frequency f of the waves can be calculated from the wavelength and the speed of the waves, which is the speed of light c:.
R Jessop  uses a Lecher line anode tank. Notify me of new posts via email. Detecting really tiny current with a long filament, huge magnets, and some optics. Leave a Reply Cancel qire Enter your comment here Lecher wire demonstration apparatus with lamp for indicating the point of resonance. The other method used to find the nodes is to slide the terminating shorting bar up and down the line, and measure the current flowing into the wie with an RF ammeter in the feeder line.
Permission Reusing this file. Lecher line, oscillator and other equipment. Something else is still up…. Notify me of new comments via email.
Using a Lecher Line To Measure High Frequency | Hackaday
Austrian physicist Ernst Lecherimproving on techniques used by Oliver Lodge  and Heinrich Hertz developed this method of measuring wavelength around Newnes Guide to Television and Video Technology.
Here I thought it was men in overcoats and galoshes at the ticket counter of an X-rated movie theatre. I measured the frequency by spanning three of them and then multiplying by three. The frame must be made of a nonconductive material like wood, because any conducting objects near the line can disturb the standing wave pattern.
Summary [ edit ] Description Lecher wires and oscillator Ldcher are commenting using your Twitter account. A Lecher line consists of two parallel wires or rods that form a balanced transmission line. So the distance my screwdriver was off by was 0.
Radio electronics Distributed element circuits. Dictionary of Pure and Applied Physics. Email required Address never made public.
If the indicator has lechsr low an impedance it will disturb the standing wave on the line, so a high impedance indicator must be used; a regular incandescent bulb has too low a resistance. Views Read Edit View history.
Using a Lecher Line To Measure High Frequency
The voltage goes to zero at nodes located at multiples of half a wavelength from the end, with maxima called antinodes located midway between the nodes. You are commenting using your WordPress. Lecher line wavemeters are usually built on a frame which holds the conductors rigid and horizontal, with a track that the shorting bar or indicator rides on, and a built-in measuring scale so the distance between nodes can be read out.
Thanks for suggesting that. Check this out it probably has a few other neat methods in it too: Lecher and early researchers used long thin Geissler tubeslaying the glass tube directly across the line. Why does this so drastically differ from the values in the datasheet?