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An "aggregate" result summary can be accessed by pressing the
LIM
soft key. This performs a limit check of all channels contained within
the scan and reports an overall pass/fail conclusion. The aggregate
limit check is not performed with each scan update, however, a
Check
soft key is provided to repeat the limit check whenever
desired.
The
Limits On/Off
soft key toggles the limit check feature on & off.
When turned off, the limit annunciators do not appear.
4.7 HOW TO MEASURE C/N
It is a good engineering practice to use a bandpass filter on the input
of the receiver when making C/N measurements. This is to ensure
accuracy and extend measurement range. If a preamplifier is used to
boost test point levels prior to measurement, it should be placed
between the bandpass filter and the receiver. This measurement is
simply a comparison in amplitude between the video carrier refer-
ence signal and the noise (FCC limit: > 43 dB). The noise measure-
ment must be made at least 2 to 2.5 MHz from any other carrier on
the system.
Summary of Contents for 3SR
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