Ramsey Electronics DA25 manual

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before we snapped the rope, the sound waves would arrive much quicker than the “rope wave” would. In the case of radio waves, the rate at which the waves travel is much faster, reaching the speed of light (186,000 miles / second, or about 3x108 meters / second) in a vacuum. Radio waves do travel slightly slower in air however. In a wire transmission line, they travel even slowly!

Frequency and Wavelength

Since all antennas collect electromagnetic waves, lets take a moment to think about the wave motion of the radio wave itself. Try to picture a repeating sinusoidal waveform moving down a line (oscillating). A wave that repeats itself has a certain period (amount of time) that it takes to complete a full cycle. Since this cycle is regular, we say that the wave has a frequency of repetition. This frequency in fact is the reciprocal of the time it takes for the wave to complete one full cycle, mathematically speaking f = 1 / T. By the same token the time and frequency are related by the expression T = 1 / f.

The distance in free space that the wave takes to repeat itself is said to be the wavelength and can be calculated using the same velocity equation. By rearranging the velocity equation algebraically, we can say that the Distance = Velocity x Time. Since we will approximate the velocity to be the speed of light (“c”), once the Time is determined we can solve for the distance traveled which is the wavelength; usually denoted as the Greek letter lambda (“λ”) reducing our equation to λ = v x T. In English, the wavelength is equal to the velocity multiplied by the period of the waveform. Pretty neat, huh!

Electromagnetic Wave

One Wavelength

One Cycle

Some Amount of Time

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Contents Broadband Discone Antenna KIT Ramsey Transmitter Kits DA25 Introduction Page DA25 DA25 Discone Description DA25 ˆ 1 7 inch pie-plate CAUTION, Edges MAY be Sharp Parts Supplied with Your DA25 KITEnough of that… lets get started DA25 Discone Antenna KIT AssemblyDA25 Solder Here Bottom Copper Plated side Coaxial Cable Solder Points Congratulations Important Note Concerning Outdoor Usage Installation of the Antenna MountTroubleshooting Guide Using Your DA25 Discone AntennaConclusion Ramsey Kit Warranty Ramsey ELECTRONICS, INC Required ToolsAdditional Suggested Items