Figure 95. Test setup for interference measurement.

Figure 95. Test setup for interference measurement.

(4) If tuning unit 2, 3, or 4 is installed

b. O n t h e I G - 1 1 5 i m p u l s e g e n e r a t o r ,

in the main unit, rotate the SIGNAL

proceed as follows:

A T T E N U A T O R DB control to 20.

(1) Set the POWER switch to the ON

(5) W i t h the test setup as indicated

position.

( f i g . 95), record the pointer de-

(2) S e t the PULSE POLARITY switch

flection on the panel meter of the

to the + position.

unit under test.

(3) Set the DB ABOVE lV/MC coarse

d. On the IG-115 impulse generator. . set

and fine output level controls to a

t h e POWER switch to OFF.

v a l u e of 20 db greater than the

s e t t i n g s shown in the calibration

e. On the unit under test, perform the

c h a r t s (4A and 4B) supplied with

following procedure:

(1) Set the calibration switch to SHUNT

each test set. The tuning unit and

f r e q u e n c y selected will determine

CAL.

(2) Set the IMPULSE GENERATOR DB

the DB ABOVE lV/MC corase

and fine output level settings. For

ABOVE lV/MC switch to ON.

i n s t a n c e , if the calibration chart

(3) S e t the impulse generator coarse

s h o w s a control setting of 62 db

a n d fine output controls to those

for the frequency selected, set the

settings that produce the same

D B ABOVE lV/MC coarse and

pointer deflection as in c(5) above.

fine output level controls to a value

The settings of the output controls

of 82 db.

m u s t correspond within 1 db of

C . On the unit under test, proceed as

t h e calibration chart control set-

follows:

t i n g shown for the frequency se-

(1) R o t a t e the function switch to the

lected.

CW PEAK position.

(2) S e t t h e t h e c a l i b r a t i o n s w i t c h

105. CW Sensitivity

to SERIES CAL & OPERATE.

a. With a tuning unit plugged into the

(3) If tuning unit 1 is installed in the

m a i n unit, use the same test setup as in

main unit, rotate the SIGNAL AT-

figure 94 except for substituting the 10-db

T E N U A T O R DB control to the 0

pad (para 100) for the 5-db variable step

CW ONLY position.

222