Wavetek 3001 Instruction Manual page 50

T
he re maining %ΑΜ accu racy, whic
h
is ±15% of the
r
ea d ing + 1% of full
scale), is measure d by th e
m
odu lation
m
eter wit
h
accurately measu red
voltage applied to
t
he
m odu lation system. The measurement uncertai n ty
is 2% of the
r
ea ding + 1% of full scale.
1 . Set
t
he instrument controls as follows:
FRED VERN IER CA L
Frequency selector 520 .000 MHz
M
OD ULATIO N M OD E CW
MOD ULATIO
N
FRED DC
M
OD ULATIO N FM/AM 0% AM
OUTPUT VE RN IER -3
d
8
O UTPUT Step Attenuator 0
d
am
2.
Connect the equ ipme n t as show n in F ig ure 4-3. Co nnect t h e ce
n
te r
co n d uctor of the cable between
th
e
h
igh ter minal of th e
d
igital m υ12 ί-
meter and
t
he
M
OD ΤΡ (pin 36 of
r
ear- p anel PR OG RAMM ING j
ack
J 101) . Co nn ect t he cable shield between the low te rminal of t h e
d
igital
m
ultimete r
a
nd ground ( p in 25 of
J
101) .
3. Set the
M
ODUL ATION FM/AM slider to its fu ll up position.
4. T
h
e
d
igital mu ltimeter should rea d 5.000 -0 .020 VDC . If the voltage
is within li mits, continue to step 5. If not, recali brate (Section 5.3 .9).
5. Set the
M
ODUL ATIO N FM/AIM slider to 30% AM .
6.
T he
d
igital multimeter should read betwee n 1 .300 a nd 1 .700 VDC .
Record
t
he reading on li ne 31 of the PTR.
7. Set t he M OD UL ATIO N FM/AM sli der 2ο 90% AM,
8.
The
d
igital
m
ulti meter shou ld
r
ea d between 4 .300 an d 4.700 VDC .
R
ecord
t
he reading on line 32 of
t
he
P
T R. NOTE : This co nclu des t h e
M
ODULATIO N FM/AM con t rol accuracy test . As ma ny ot her
p
oints may
b
e tested as
d
esired.
9. Adjust the
M
OD UL ATIO N FM/AM sli der to 0% AM,
10 . Set the modulation meter to read %ΑΜ at 520 MHz. Set t he mete r
range switch to 100, the R F inpu t atte nu atio n to 10
d
8, th e I F band wi d th
to +_400 Hz,
t
he mete r res ponse 2σ fast, the fun ction switch to +AM, and
t
he filter
b
and width to 50 Hz - 15 kH z.
11 . Adjust the MOD ULATIO N FM/AM slider fo r α reading of 1 .500
±0.003 VDC on the
d
igital mu ltimeter. Set
t
he
M
OD ULATIO N FRE D
switch to 1 kH z and
t
he MODU L ATIO N MOD E switch to AM .
12 .
M
ake α note of the
m
o du lation m
eter reading in %ΑΜ . Set the
m
odu-
lation meter fun ction switch to -AM,
a
nd note the
m
o d ulation mete r %ΑΜ
r
eading as
b
efore. Co mpu te t h e average of th e two
r ea di n gs . T h e average
%ΑΜ
s
hou l d be betwee n 27 .5 and 32 .5%.
R
ecord
t
he ave r age %ΑΜ to t
h
e
n
earest 0.5% on li ne 33 of th e
P TR.
4-15