User's Manual
02/10/2012
© 2012 Meteorcomm LLC. All Right
Cosmic Noise
Cosmic noise is the limiting noise factor in a meteor burst system
noise is generated by star systems in the galaxy and is frequency
dependent.
The noise is approximat
and 13 dB above thermal at 50 MHz
the highest when the antennas are pointed directly at the center of the
galaxy and lowest when they are pointed at right angles to it
variations of 3 to 4 dB can be expected
one that is limited only by cosmic noise.
Power Line Noise
One of the main sources of man
Noise on these lines is generated by high voltage bre
on power line hardware such as transformers and insulators
can be seen with an oscilloscope at the Receiver IF test point as a series
of spikes that occur every 8 msec (1/60 Hz) or every 10 msec (1/50 Hz)
The level of the spik
floor.
The number of spikes can vary, depending upon the level of
interference, from one or two every 8
8-10 msec.
The impulse noise blanker in the MCC
a
mount of this type of noise
increase, the effectiveness of the blanker is reduced
site always, check the IF test point with a scope to determine the level
of the power line noise interference
noise be avoided for an optimum site
well away from power lines.
Note
power lines to reduce noise. Call the local utility in case of severe
noise.
Automobile Ignition Noise
Automobile ignition noise is generated by all gasoline engines and is a
result of the high voltage required to fire the spark plugs
noise is similar to power line noise, with the exception that it does not
have the regular 8
Computer-
Generated Interference
545C Operations Manual
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hts Reserved.
Proprietary and Confidential. Do Not Distribu
Cosmic noise is the limiting noise factor in a meteor burst system
noise is generated by star systems in the galaxy and is frequency
The noise is approximat
ely 15 dB above thermal at 40 MHz
and 13 dB above thermal at 50 MHz
.
This noise is diurnal in nature
the highest when the antennas are pointed directly at the center of the
galaxy and lowest when they are pointed at right angles to it
variations of 3 to 4 dB can be expected
.
An optimal meteor burst site is
one that is limited only by cosmic noise.
Power Line Noise
One of the main sources of man
-
made noise is high voltage power lines
Noise on these lines is generated by high voltage bre
akdown occurring
on power line hardware such as transformers and insulators
can be seen with an oscilloscope at the Receiver IF test point as a series
of spikes that occur every 8 msec (1/60 Hz) or every 10 msec (1/50 Hz)
The level of the spik
es is much higher than the normal background noise
The number of spikes can vary, depending upon the level of
interference, from one or two every 8
-
10 msec to several dozen every
The impulse noise blanker in the MCC
-
545C removes a large
mount of this type of noise
.
However, as the number of spikes
increase, the effectiveness of the blanker is reduced
.
When setting up a
site always, check the IF test point with a scope to determine the level
of the power line noise interference
. It is mand
atory that power line
noise be avoided for an optimum site
.
Try to place the receiver antenna
well away from power lines.
Note
:
Power companies are required to properly maintain their
power lines to reduce noise. Call the local utility in case of severe
noise.
Automobile Ignition Noise
Automobile ignition noise is generated by all gasoline engines and is a
result of the high voltage required to fire the spark plugs
.
noise is similar to power line noise, with the exception that it does not
have the regular 8
-
10 msec period associated with power line noise.
Generated Interference
545C Operations Manual
DCN 00001789-A
ibute.
21
Cosmic noise is the limiting noise factor in a meteor burst system
. This
noise is generated by star systems in the galaxy and is frequency
ely 15 dB above thermal at 40 MHz
This noise is diurnal in nature
. It is
the highest when the antennas are pointed directly at the center of the
galaxy and lowest when they are pointed at right angles to it
. Daily
An optimal meteor burst site is
made noise is high voltage power lines
.
akdown occurring
on power line hardware such as transformers and insulators
. This noise
can be seen with an oscilloscope at the Receiver IF test point as a series
of spikes that occur every 8 msec (1/60 Hz) or every 10 msec (1/50 Hz)
.
es is much higher than the normal background noise
The number of spikes can vary, depending upon the level of
10 msec to several dozen every
545C removes a large
However, as the number of spikes
When setting up a
site always, check the IF test point with a scope to determine the level
atory that power line
Try to place the receiver antenna
Power companies are required to properly maintain their
power lines to reduce noise. Call the local utility in case of severe
Automobile ignition noise is generated by all gasoline engines and is a
.
Auto ignition
noise is similar to power line noise, with the exception that it does not
10 msec period associated with power line noise.