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6 METERS – “The Magic Band”. Two-Way radio communication on 50 MHZ. 6 meters is a very unique amateur band. Just about every mode of propagation known to exist can be found here. 6 Meters plays well with several FORMS of propagation. Some 6 Meter History.
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6 METERS – “The Magic Band” Two-Way radio communication on 50 MHZ.
6 meters is a very unique amateur band. • Just about every mode of propagation known to exist can be found here. 6 Meters plays well with several FORMS of propagation
In 1924, the 5-meter band (56–64 MHz) was first made available to amateurs in the United States
1927, the band was allocated on a worldwide basis by the International Radiotelegraph Conference 56–60 MHz was allocated
There were several changes made as far as power restrictions and operating times with early television stations occupying this same band space.
ARRL lobbies to the FCC for a change in the band plan. The ARRL Gets Involved!1947
The ARRL stepped in and convinced the FCC there were several “Unique Propagation Properties” and requested they assign the 6 meter band to 50-54 mhz. Arrl Lobbyists pressed hard for The Perfect Spot
About every 11 years the sun spot cycle explodes. • These solar storms produce sufficient amounts of radiation to activate the F-layer - producing a very radio reflective surface. • A sun spot number of @ 115 is needed for the M.U.F. (maximum useable frequency) to reach 50 mhz. • When this happens, 6 meter signals can be propagated to distances well past 10,000 miles!!!! • The height of the F2 layer reflects single hop distances @ 2,500 miles. F-Layer Propagation
A very interesting propagation modes is called Trans-equatorial propagation. • TEP is the scattering from ionospheric irregularities at very high altitudes. • TEP was discovered by amateurs during the late 1950’s. • TEP is frequent between March and September, usually in the late afternoon and early evening. • During the solar cycle peak. TEP signals can often exceed 400 mhz. Trans-equatorial Propagation“TEP”
http://home.iprimus.com.au/toddemslie/aTEP-Harrison.htm Roger Harrison
Sporadic E normally produces peak during the summer months of May through August, and then again with a minor peak in the winter months of November and December. • Sporadic E is reflections from dense patches of ionization that form at E-layer heights. • The height of the E-Layer reflections produce single hop distances @ 1200 miles. • Single / Double / Triple hop Sporadic E has occurred with distances exceeding 5,000 miles. Sporadic “E” Propagation
Sporadic E is an interesting form of propagation because it is still being studied. • Some believe that storms and wind shear might have some major effects. • Several Japanese hams believe that there are several types of Sporadic E variations and that summer heating comes into play. It has been called “SSSE” – Summer Season Sporadic E propagation. Sporadic “E” Still So Much ToLearn
Spring “E” Season Is Right Around The Corner!!
To make use of this phenomenon, radio amateurs actually bounce their signals off of the Aurora Borealis, also known as the “Northern Lights.” • SSB signals are raspy. • Signals propagating through the Aurora are fluttery. • CW signals appear to be modulated by white noise. Aurora propagation
In most cases - nearby stations cannot hear each another due to the skip or silent zone that surrounds them. • Back Scatter is most prevalent on 6 and 10 meters. • Usually on the HF bands you cannot hear stations in a range of about 125 - 200 miles around your location - BUT you can get better results on the lower bands where the skip distance is shorter. • But under "Special Ionospheric Conditions" these two "same" nearby stations might be able to communicate thanks to Back or Side Scatter. Back scatter propagation
Tropospheric Propagation refers to the way radio signals travel through the lowest layer of the Earth's atmosphere, the troposphere, at altitudes up to @ (11 miles). • Weather conditions in the lower atmosphere can produce radio propagation over greater ranges than normal. • If a temperature inversion occurs, with upper air warmer than lower air, VHF and UHF radio waves can be refracted over the Earth's surface instead of following a straight-line path into space or into the ground. • “Tropospheric Ducting" can carry for (500 miles) or more, far beyond usual range. Tropospheric“TROPO” propagation
Meteor Scatter is a propagation mode – more realistically “An Event” that uses the ionized trails of meteors during entry into our atmosphere to establish brief communications paths between stations up to (1,400 mi) apart. • As the earth moves along its orbital path, billions of particles known as meteors enter the earth's atmosphere every day a small fraction of which have properties useful for point to point communication. • When these meteors begin to burn up, they create a trail of ionized particles in the E layer of the atmosphere that can persist for up to several seconds. • The ionization trails can be very dense and thus used to reflect radio waves. • The frequencies that can be reflected by any particular ion trail are determined by the intensity of the ionization created by the meteor, often a function of the initial size of the particle, and generally size up to be perfect for 6 Meters. Meteor Scatter propagation
Airplane scattering is observed on 6 meters as well as 2 meters. • This yields momentary “Artifial” propagation up to 400 miles even in mountainous terrain. • Aircraft Scatter is usually in play when you are hearing “Picket Fencing” on signals. Aircraft Scatter propagation
Now to confuse us all! These propagation types can intermix with each other. Giving us several different “ENHANCEMENTS”
OK We Are At The Bottom Of The Current Solar Cycle
“THEY” Say The Bands Are Dead!!
IF THIS IS THE “BOTTOM” OF THE SOLAR CYCLE…
AUGUST 9th 2018 THURSDAY
Imagine the PEAK of the Cycle
