Understanding Antennas For the Non-technical Ham by N4JA - An online Book!

Understanding Antennas For the Non-technical Ham by N4JA - An online Book!: "meters or 20 meters. It just depends on the stage of the sunspot cycle. During the years with high sunspot numbers, nearby contacts are possible all day. At night, the skip lengthens making contacts possible to those parts of the world where it is still dark. Working DX on 40 meters is a nighttime or greyline event. When the sunspots are low, forty meters may have long skip during the day, and nearby contacts may be impossible or they may be very weak. During the time when we suffer from low sunspot numbers, many DX contacts are made during early morning, late afterno"

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Attenuation - Wikipedia, the free encyclopedia

Attenuation - Wikipedia, the free encyclopedia: "Radio
Main article: Path loss
Attenuation is an important consideration in the modern world of wireless telecommunication. Attenuation limits the range of radio signals and is affected by the materials a signal must travel through (e.g., air, wood, concrete, rain). See the article on path loss for more information on signal loss in wireless communication."

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Impedance - Wikipedia, the free encyclopedia

Impedance - Wikipedia, the free encyclopedia: "Impedance may refer to:
Electrical impedance, the ratio of the voltage phasor to the electric current phasor, a measure of the opposition to time-varying electric current in an electric circuit
Characteristic impedance of a transmission line
Nominal impedance, approximate designed impedance
Wave impedance, a constant related to electromagnetic wave propagation in a medium
Impedance of free space, a universal constant
Mechanical impedance, a measure of opposition to motion of a structure subjected to a force
Acoustic impedance, a constant related to the propagation of sound waves in an acoustic medium"

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Thermal Compound Roundup - February 2012 | Hardware Secrets

Thermal Compound Roundup - February 2012 | Hardware Secrets:


The difference between room temperature and CPU temperature (lower equals better performance).



New Software for Mac OS X