Model
5340A
Operation
3
-
11. Sample Rate, Measurement Time, and Reset
3
-
12.
The sample rate control sets the interval between measurements, but not the interval of the
measurement. On the
5340A,
the minimum sample rate
is
variable between approximately
50
milliseconds and
5
seconds. For
1
Hz RESOLUTION settings, an additional
1
sec delay
is
incurred.
A
hold feature can be selected to “freeze”
a
measurement display indefinitely.
\
3
-
13.
The measurement interval (gate time)
is
the time that the counter’s gate remains open to
accumulate counts. In the
5340A,
the gate time
is
a
function of the resolution selected and the
input frequency. Typical measurement time for an
18
GHz signal with
1K
resolution selected is
about
120
msec. With
1
Hz resolution selected and an
18
GHz input, the gate time
is
quite long,
approximately
120
seconds. However during this time, the LOCK annunciator lights to indicate
that a measurement
is
in progress.
3
-
14.
Reset
is
accomplished by pressing the RESET switch or changing the RESOLUTION or
RANGE switch. When the counter
is
reset, the display reads all zeros and ahew measurement
cycle is initiated.
3
-
15.
AM
Characteristics
3
-
16.
The
5340A
will measure inputs containing amplitude modulation provided that the mini
-
mum level of the input signal is greater than the sensitivity specification. The maximum modu
-
lation permissible can be calculated by the following formula:
vu
-
vs
vu
=
%
modulation where: Vu is the unmodulated
rms
input level.
Vs is the sensitivity specification
at
the frequency
of interest.
As
an example of the use of the formula, calculate the maximum permissible modulation for
a
-
10
dBm
(70
mV) input
at
10
GHz. At
10
GHz, the sensitivity specification
is
-
35
dBm (4 mV)
Using the formula:
Vu
-
Vs
-
70mV
-
4mV
-
-
66
mV
=
94.5%
modulation
vu
70
mV 70 mV
3
-
17. FM Characteristics
3
-
18.
phase modulation, or residual noise.
rate and carrier frequency
as
shown
in
Figure
3
-
1.
The
5340A
will measure carrier frequencies in the presence
of
frequency modulation,
The FM characteristics are a function of the modulation
Figure
3
-
1.
FM Characteristics
I I I
I
I
10
100 1K 10K 1 OOK 1M
1,
-
MODULATING
FREOUENCY
-
Hz
3
-
2
To Next Page
Loading...
Need help?
General
