84
The SGC Building, 13737 S.E. 26th St. Bellevue, Washington 98005 USA
P.O. Box 3526, 98009 Tel: (425) 746-6310 Fax: (425) 746-6384
© 1997 SGC Inc.
Even though you might be stuck in a location where man-made noise is abundant, you don't have to be bothered
by this interference. A number of different techniques can eliminate some or all of the noise at the source, or by
filtering or changing that noise.
DSP is one of the new audio technologies that is just starting to take off. With DSP technology, the radio audio
is turned into digital signals and certain patterns, such as noise patterns, can be filtered out. In some cases, it might
even be possible for the audio signal to be partially reconstructed. It won't be long until DSP technology is contained
in most every radio. Just as digital frequency readout boxes were available for every transceiver 25 years ago,
separate DSP boxes will soon look archaic and it will be assumed that the technology will be in every radio 25 years
from now.
The noise blanker is a circuit that is effective in limiting quick, "pops" in the audio. When a loud, quick noise
occurs, the noise blanker turns the audio circuit off for a very brief amount of time. The circuit is turned off and on
so quickly that you don't even realize that it happened. Noise blankers only work with brief "pops;" if a noise
blanker is used with a constant noise source, the audio will be reduced and effect will be similar to using an
attenuator.
Magnetic antennas have nothing to do with car whip "mag mounts" or a tacky antenna that you could stick on
your refrigerator. These antennas are all types of loop antennas, which receive the magnetic component of radio
waves and not the voltage component. As a result, although the received signals are at a lower level, the interference
is also greatly reduced.
DIGITAL SIGNAL PROCESSING (DSP)
NOISE BLANKER
MAGNETIC ANTENNAS
NOISE REMEDIES AT THE TRANSCEIVER
To Next Page