Oct. 13, 2014

Hi good afternoon.


Theoretical physicists are now saying that different matters in the universe are just waves, waves of different frequencies. The universe is alive with oscillations. If you look at the wave spectrum or frequency spectrum, we can go down to one kilohertz and even lower and the upper end are gamma rays. It between are sound waves, radio waves, light waves, x rays etc. Light waves are waves visible to our eyes. But we cannot see radio waves. We can feel some waves, the heat waves. There is one light wave that we cannot see:infrared.

When we drop a pebble in a lake, the waves travel outward in ripples. Waves travel and therefore, it must have speed. Radio waves and Light waves travel at 300 Million meters per second or at 300 x 10 to the 6. It takes the light from the sun 8 seconds to reach earth. All images in the sky took years traveling at the speed of light to reach our eyes.

WAVES VARY IN LENGTH

     Waves have lengths and is called wavelengths. The wavelength is inversely proportional to its frequency.
When we say 2 Meter band, the WL is 2 meters.What is the frequency. Well, it is easier to view it this way. If the wave traveled 300 M meters in one second, and the wavelength is 2 meters, there are 300M meters/2 repetitions as it travels in one second. Thre frequency therefore is 150 million hertz or 150 Mhz. so, the formula is:

          WL=300 M/ Freq. in Mega hertz. Thus at a frequency of 150 Mhz, it is 300 M/150 Mhz= 2 meters.

Look at the waves as a crawling caterpillar on a long stick. The caterpillar arches like a letter S and the distance its body covers is the WL. The shorter it is, the more cycles it has to make to  cover a distance. A radio wave is a sine

Let us go to reality. The MW BC band in AM is around 1 Mhz in the middle (.640-1.640Mhz). What is the meter band for this band? It is 300/1 or 300 meter band. in the shortwave band, at 7.7Mhz, what is the WL? It is 300/7.5=40 Meter. The CB band is 11 meters (300/27). The FM band is around 3 Meter at 100 Mhz. As we go higher into the UHF band like the 430 Mhz for amateurs, the WL is about .7 meters. our cellphones are at 900 Megs, 1.8 Gigahertz and other services today are at 2.4 Gigahertz. They are in the microwave region.