MFJ-935C
High-Efficiency Magnetic Loop Tuner
Instruction & Technical Manual
1
RADIO FREQUENCY HAZARDS
1.1
BACKGROUND INFORMATION
The following warning is printed on the back of the MFJ-935C
High-Efficiency Magnetic Loop
Tuner/Antenna Current Meter
™
.
WARNING
DO NOT touch or come into contact with Loop Connectors or
Loop Antenna while transmitting
YOU CAN BE SERIOUSLY INJURED
The MFJ-935C
High-Efficiency Magnetic Loop Tuner/Antenna Current Meter
™
can, and in fact
does, produce
LETHAL VOLTAGES
and
HIGH CURRENTS
during normal operation. The
high-Q circuit produced by resonating the wire loop connected to the tuner, and matching it to the
50Ω coax supplying power creates this unique operating environment.
NOTICE
It is imperative that the operator specifically follows the operating
instructions and complies with all CAUTIONS, WARNINGS, and FCC
Guidelines for Human Exposure to Radio frequency (RF) Electromagnetic
Fields.
1.2
RADIO FREQUENCY RADIATION
Radio frequency (RF) energy is one type of electromagnetic energy. Electromagnetic waves and
associated phenomena can be discussed in terms of energy, radiation, or fields. Electromagnetic
radiation is defined as waves of electric and magnetic energy moving together, or radiating,
through space. The movement of electrical charges generates these waves. For example, the
movement of charge in a radio station antenna (the alternating current) creates electromagnetic
waves that are radiated away from the antenna and intercepted by receiving antennas. The term
electromagnetic field refers to the electric and magnetic environment existing at some location due
to a radiating source such as an antenna.
An electromagnetic wave (Figure 1) is characterized by its wavelength (
λ
) and frequency (
f
). The
wavelength is the distance covered by one complete wave cycle. The frequency is the number of
waves passing a given point in space over a second. For example, a typical radio wave transmitted
by a 2-meter VHF station has a wavelength of about 2 meters and a frequency of about 145 million
cycles per second (145 million Hertz): one cycle/second = one Hertz, which is abbreviated Hz.
-1-
Содержание MFJ-935C
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