Fm Dev Iation Accur Acy Test; F Mbandwidth Test - Wavetek 3001 Instruction Manual

4.14 FM
D
EVIATION ACCUR ACY T EST
SPE CI FICATIO N
+-500 Hz on FMx1 ra n ge ; t5 kH z an FM x10
r
a n ge.
M
ET H OD
The
d
eviation is measured in both FM modes
u
sing an inte rnal DC voltage
equ al to the peak of
t
h e internal si ne wave voltages. Α
f
requ ency counter
is
u
se d to
m
easure the
m
aximum deviation in
b
ot h FM
m
odes .
E
QUIPMENT
PROC EDURE
4.15 FM BANDWIDTH
T
EST
SPE CI F ICATIO N
4- 18
1 . Set the i nst rum ent controls as follows :
FRE D VERN IER
0 kH z
F requency selector 050.000 MHz
MOD UL ATIO N M OD E FM xt
M OD U LATIO N FRED DC
M OD ULATION FM /ΑΜ 10 kH z on FM scale
OUT PU T VERN I ER
F ull εω
O UTPU T Step Atte nu ator +10
d
Bm
2.
Connect
t
he 50 o h m inpu t of the frequency counter to the RF OUT
co nn ecto r.
3.
R
ead
t
he frequency counter and record
t
he reading to 8
p
laces
on
line 38 of t h e PTR .
4. Adjust the
M OD UL ATION FM/AM slider to 0 kH z
d
eviation on
t
he
FM scale.
5.
R
ead the frequency
counter a
nd record the reading
to
8
p
laces
on
.
li ne 39 of the P TR.
Β. Subtract the
r
eading ob taine d in step 5 from the
r
ea d ing o btained in
step 3. The
d iffe r ence
b
etween
t
h e two readings should be between 9.500
and 10 .500 kH z.
R
eco r d the
d iffere nce in kH z on line 40 of the
P
TR .
7. Set the
M
OD ULATIO N MOD E TO FM x10 a nd a djust the MODU-
LATION FM /ΑΜ slider to 10 kH z deviatio n of the FM scale.
8.
R
ea d
t
he fr eq uency co un te r
a
nd record
t
he reading to β
p
laces on
line 41 of the PTR
9 .
Ad ju st the MOD ULATIO N FM/AM slider to 0 kHz deviation on
t
he
FM scale.
10 .
R
ead
t
he frequency counter and reco rd the read ing to 6 places on
li ne 42 of
t
he P T R .
11 . Subtract
the
reading obtained
in
step 10 from
t
he
r
eading obtained
in step Θ. The
d
iffere nce
b
etween the two
r
ea di ngs should be
b
etween
95 .0 and 105.0 kH z. R
ecor d the
d iffe rence i n kHz on line 43 of the
P
TR .
External, 50 Hz to 15 kH z, (1 dB ban dwi dth), input level requ i red = 10
Vpp into 600 ohm s to provide cali b rated
d
eviation co ntrol .
IDC to 25 kH z when FREQ VERN I ER is
n
ot in CA L p osition .)