HP 8901B Operation And Calibration Manual page 349

Model 8901B
Performance Tests
Characteristic
FREQUENCY MODULATION
(cont'd)
Residual
FM
AMPLITUDE MODULATION
FM
Rejection(2)
Performance Limits
<8
Hz
rms at
1300 MHz
decreasing linearly
with
frequency to
<1
H z rms
for
100
MHz and below
<0.2% AM
<0.2% AM
Conditions
50
H z to
3
kHz bandwidth
250 kHz
to
10
MHz carrier:
e5 kHz peak deviation;
400
and
1000
H z rates;
50
H z to
3
kHz bandwidth
<50 kHz peak deviation:
400
H z and
1
kHz rates;
50
H z to
3 kHz
bandwidth
10
to
1300
MHz carrier;
( 2 )
Peak residuals
must
be accounted for in peak readings. (Refer to
Residual Noise Effects
in
Detailed
Operating lnsfrucfions
in Section
3.)
Description
FM is measured with a very low-noise oscillator at the Modulation Analyzer's input. The resulting
measured FM is the residual FM of the Modulation Analyzer's internal local oscillator. FM accuracy is
measured with the internal FM Calibrator, which produces approximately 34 kHz peak deviation at a
10
kHz rate. A source, which can produce wide-band, linear FM,
is modulated
at various FM rates and
deviations to measure distortion, flatness, and incidental AM. A special AM/FM test source is required
for these tests to assure that the FM source has adequate bandwidth, low distortion, low residual FM,
and low incidental AM.
Equipment
AMfFM Test Source
.............................................................
H P 11715A
Audio Analyzer
...................................................................
H P 8903B
Audio Synthesizer.
................................................................
H P 3336C
CAL
HP 89016
MODULATION ANALYZER
0
AUDIO SYNTHESIZER
OUTPUT
( S t e p s 1 . 3 0 )
MODULATION
OUTPUT/
OUTPUT
AUDIO ANALYZER
- A U D I O
INPUT
z:::;
000000
0000 0
: ; ; ; ;
0
0 0
0 0 0 0 0 0 0
0000
0
(Step
1 5 )
INPUT
D O
0
I BRAT
I
ON INPUT
A W F Y
OUTPUT
L W RESIDUAL OUTPUT
( S t e p
I
F i n r e
4-2.
FM Performance Test Setup
Performance Test 2
4-9