IVIE IE-10A, Руководство владельца и оператора

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MEASURING AUDIO SYSTEMS
and l o s s measurements a r e u s u a l l y considered t o be r e l a t i v e measurements.
T h a t i s , g a i n and l o s s a r e n o t d e s c r i b e d i n a b s o l u t e u n i t s l i k e v o l t s ,
o r dB-SPL. Gain and l o s s measurements a r e comparisons o f t h e o u t p u t
s i g n a l d i v i d e d by t h e i n p u t s i g n a l and a r e u s u a l l y expressed i n a
u n i t l ess measure.
Using t h e g a i n and l o s s can be measured w i t h e i t h e r a s i n e wave
generator, o r w i t h a p i n k n o i s e generator. The advantage of u s i n g a
p r e c i s i o n p i n k n o i s e g e n e r a t o r , i k e t h e i s t h a t both g a i n ( o r
o s s ) and frequency response a r e d i s p l a y e d s i m u l taneously.
For g r e a t e r
d e t a i l on p i n k n o i s e a p p l i c a t i o n s and t e s t s , r e f e r i n t h e o p e r a t o r ' s
manual t o t h e s e c t i o n s a b o u t p i n k noise.
1 s t EXAMPLE
Measure t h e g a i n o f a p r e a m p l i f i e r w i t h a 10 mv i n p u t s i g n a l a t a
frequency o f 2 KHz.
Procedure :
1.
Set up t h e equipment as shown w i t h t h e o u t p u t l e v e l of t h e s i n e -
wave generator s e t t o zero.
AMPLIFIER
UNDER
1
TEST
2
F i g u r e 34
2.
Most p r e a m p l i f i e r s have a v e r y low o u t p u t impedance and do n o t
u s u a l l y r e q u i r e a t e r m i n a t i n g oad. Power i f i e r s shoul d ways
be t e r m i n a t e d w i t h an a p p r o p r i a t e l o a d when measuring t h e power,
g a i n o r frequency response.
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