APPLICATIONS
2 . M e a s u r e m e n t
o f
pulse c i r c u i t t h r e s h o l d level
( F i g .
4 )
1) A d j u s t t h e voltage o f pulse c i r c u i t t o a p r o p e r level
(5-1OV f o r T T L ) , t h e n set R A - 9 2 0 t o 0 d B .
2) A d j u s t R A - 9 2 0 so t h a t t h e o u t p u t disappears f r o m t h e
o s c i l l o s c o p e !
3) Where t h e reading o f R A - 9 2 0 is 5 , t h e t h r e s h o l d level
is e
Q
, and t h e pulse generator o u t p u t is e j ,
e
0
= e
j X
L O G
- 1
In m e a s u r e m e n t , be sure t h a t t h e pulse f r e q u e n c y is
b e l o w 1 0 0 k H z , t h e signal is p r o p e r l y sheilded a n d
t h e load i m p e d a n c e is adequate.
3. A u d i o m i x i n g ( F i g . 5)
B y using t w o R A - 9 2 0 , it is possible t o a t t e n u a t e t w o
i n d i v i d u a l signals f o r a u d i o m i x i n g .
Oscilloscope
TRIG
Speaker
Speaker
Fig.
4
Fig. 5
9
Pulse
generator
RA-920
60on
Pulse
circu it
MIC
amplifier
RA-920
Tape
recorder
RA-920
Mixing
amplifier
Main
amplifier