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3 .
Set the signal generator output level to .10
d
Bm, the
m
ode to C
W
,
and ι h ε
f
requency to 250 MHz.
4 .
Set the spectrum analyzer to span 0 to 500 MHz and
t
he
b
a ndwidth
to 300 kH z.
U
se t h e log reference level controls to calibrate the 250 MHz
signal at the lot) line (0 r18 re ference) of the display gr αtίειιΙe .
5 .
Disconnect
t
h e coaxial sh ort and connect th e device-under-test port
of t he VSW R bridge to the Η F OUT connector. Tu n e t h e sign al generator
t
hroug h out the instrument's range an d verify that the signal level in the
d
is play is 21 dB below the 0 dB reference . Disregard
t
he signal at 520
MHz.
R
eco rd
t
he reading i n d8 below the reference on line 47 of t he PT R ,
< 1 .0 μV is in du ced in α two-turn, one
i
n ch diameter loop whic h is held
one inch away from any
s
urface.
L
oo p feeds a 50 ohm receiver
Α 50 ηΙιιιι receiver consisting of α 26 dB
a
mp lifier and α spectr um analyzer
.Ire calil)rate d it α 1
) ι V lονΕ l ιιτιπg th e ίιι s Ιηιιηεη t Α too',) probe is Ιh ιαι
connecte d to
t
he nceίver and the leak age is measured α [ α
o
ne-inch dis-
ta nce from Ore external surfaces of the instrument with
t
h e RF OUT
connector termi nated in 50 o hm s. Α screen room m ay
b
e
r
equ ired for
this measurement,
(8) (101 (14) 115) (16)
1 .
Set the instru ment con trols as follo
w
s:
FRE O VERN I ER
CA L
Fre quency selector
500.ODO ΜΗι
Λ40DU LATIO N MODE
CW
M OD UL ATIO N FRE D
N/A
O UTP U T VERN I ER
+3 dB
OUTP UT Step Α2τe ηυατοr
-110 dBm
2.
Connect th e equipment as
s
h o
w
n in Figure 4-7 .
3-
Set the spectr um analyzer bandwidth to 100 kHz, the sca n widt h to
0.5 MHz/division,
t
he video filter to 100 Hz,
t
he in pu t attenuation 2ο 0
d
θ
an d
t
he log refe rence level to 50 (f β m with α 10 dB /d ivision vertical scale.
Ce n ter the signal in
t
he display
u
sing the center frequency control . Cali-
brate the analyzer for the .107 dBm signal α2
t
h e -31 dBm graticule
u
sing
t he log reference co ntrols.
4.
Disconnect
t
he RF
a
mp lifier from
t
he instrum ent and connect the
50 ohm coaxial terminal to the R F
O
U T connector of t h e instrument
Tigh ten the termi nation to minim ize RF leakage.
5.
Set the OUTPU T Step Αττeπυατοr to -10 dBm
a
nd
t
he OUTPUT
VERN I ER fo r α +3 dBm rea d i ngo n
t
he outpu t ME TER .
6 .
Connect the loop probe to the in pu t of the RF
a
mp lifie r .
M
ove the
loop
p
ro be over the sur faces of the inst rument wit h
t
h e two-turn loop at
α
o
ne-inch
d
istance. The signal plus noise should he less th an t h e -107 dB m
reference (ste p 2) .
R
ecord
t
he maxi mum read ing in dBm on li ne 48 o f
t
he
P
TR .
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