(3)
dBm
S c a l e
In general, voltmeters have a reference level d i v i s i o n
of OdBm equal to 0.775V (1 mV power) induced across
a 600O resistance load. Therefore, the red d B m scale
is a v a i l a b l e to measure a power level referenced to 0
d B m , w i t h the impedance of the given power c i r c u i t
being 60012 pure resistance. Where measured across
specific resistance loads, f o r example, 1 0 k O
r
other
than the 600X1 load, the levels are sometimes
expressed in d B s .
• How to Use Remote Control
A v a i l a b i l i t y of the optional Remote Control is one of
outstanding features of your V T - 1 7 1 [ " V T - 1 7 1 E J .
T o a t t a c h the Remote C o n t r o l , remove the blind plate
a t the rear of your V T - 1 7 1 ( " V T - 1 7 1 E J . I n s t a l l and
plug the optional con-nector into the 16-pin connector
on the P C board.
The R T - 6 1 option, a remarkable feature of the V T - 1 7 1 ,
provides a remote control c a p a b i l i t y . T o use the option,
remove the case and the rear-panel blind plate, i n s t a l l
the connector supplied w i t h the R T - 6 1 , then plug the
R T - 6 1 into the 16-pin connector on the p r i n t circuit
board. F o r d e t a i l s , refer to the R T - 6 1 Instruction
M a n u a l .
How to Use Relative Reference Control
The R E L A T I V E R E F control is kept a t " C A L " in
general cases of reading c a l i b r a t e d , absolute values on
the Meter. T o measure r e l a t i v e levels such a s fre-
quency responses, t u r n the control f o r uncalibration
s t a t e ( U N C A L ) until the reference level is set to a
desired value, f o r example, OdBm. T h i s a l l o w s reading
the relative levels.
F i g u r e 4 - Meter Scale G r a d u a t i o n s .
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