Kenwood VT-172, Инструкция по эксплуатации

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R E A D I N G T H E M E T E R S C A L E S (See F i g . 3 )
(1) V O L T A G E S C A L E S
These scales consist of a 0—10 and 0 ~ 3 scale
which are used to read ranges which are multiples
of 10 and 3 respectively. The range setting a l w a y s
r e f e r s to the meter fullscale deflection. The ranges
are designed to overlap to a l l o w v a l u e s on the
lower portion of one range to be more accurately
read on the upper portion of the next more
sensitive range.
(2) d B m S C A L E S
A level of 1 m W into a 600O resistance is take
as OdBm (0.775V) and readings are made in OdBm
w i t h respect to t h i s standard reference level.
F i g . 3
6. P R E C A U T I O N S
1. T o assure accurate measurements a l l o w a f i v e
minute w a r m i n g up period before actual
measurements are begin. Note t h a t switching
between 1V and 300mV and between 1 m V arid
3 0 0 M / and 10/A/ upon powering the unit up m a y
result in the deflection of the meter.
2. T o preserve the high s e n s i t i v i t y of t h i s unit, be
sure to use either the input signal cable provided
or another low capacitance shielded cable. Use of
single conductors or other unshielded cables or high
impedance signal sources can result in noise being
introduced into the measurement c i r c u i t .
3. Be sure to take care not to exceed the m a x i m u m
allowable input levels :
10/A/—300/A/ ranges: A C : 10Vrms
D C : 500V
1 m V ~ 3 0 0 m V ranges: A C : 8 0 V r m s
5 0 0 V ( D C + A C p e a k )
. 1V—300V ranges : 5 0 0 V ( D C + A C p e a k )
F o r excessively high inputs in the 10/A/ to 300/A/
ranges the input impedance drops to a p p r o x i m a t e l y
10012.
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