Pendulum GPS-12, Руководство пользователя

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Option 71B
(0.1 & 1 & 5 & 10 MHz)
Connect a DSO with 50
W
inputs to all BNC
connectors, one at a time. Verify that the four
output signals are sinusoidal and that the volt-
age is at least 1Vrms. Connect the counter and
verify that the frequency is 10 MHz ± 0.01 Hz,
5 MHz ± 0.005 Hz, 1 MHz ± 0.001 Hz and 0.1
MHz ± 0.0001 Hz respectively.
Option 72B
(2 x 2.048 MHz & 2 x 2.048 Mbps)
Connect a DSO with 75
W
inputs to all BNC
connectors, one at a time. Verify that the output
signal is a rectangular pulse train with an ampli-
tude of ±1.2 V ± 0.12V. Connect the counter
and verify that the frequency at the two clock
outputs is 2.048 MHz ± 0.002 Hz. The ampli-
tude at the two data outputs can be checked in
the same way. For a quick check of the validity
of the encoded HDB-3 data, do like this:
–
Connect the data outputs, one at a time, to
Input A on the counter and measure ac-
cording to the procedure below.
–
Recall the default settings and make these
alterations in the INPUT A menu:
–
DC
coupling
–
50
W
input impedance
–
Trig 75 %
–
Select MEAS FUNC
®
Period
®
Single
®
A
–
Select
STAT
istics.
The result should be the clock period time mul-
tiplied by four, i.e. 4 x 488 = 1952 ± 2 ns
Standard Deviation
s
< 1 ns
Option 73B
(4 x 13 MHz)
Connect a DSO with 50
W
inputs to all BNC
connectors, one at a time. Verify that the signal
is a square wave, and that the low level is
<0.9 V and the high level >1.8 V. Connect the
counter and verify that the frequency is
13 MHz ± 0.013 Hz.
Option 74B
(2 x 1.544 MHz & 2 x 1.544 Mbps)
Connect a DSO with 75
W
inputs to all BNC
connectors, one at a time. Verify that the output
signal is a rectangular pulse train with an ampli-
tude of ±1.2 V ± 0.12V. Connect the counter
and verify that the frequency at the two clock
outputs is 1.544 MHz ± 0.0015 Hz. The ampli-
tude at the two data outputs can be checked in
the same way. For a quick check of the validity
of the encoded HDB-3 data, do like this:
–
Connect the data outputs, one at a time, to
Input A on the counter and measure ac-
cording to the procedure below.
–
Recall the default settings and make these
alterations in the INPUT A menu:
–
DC
coupling
–
50
W
input impedance
–
Trig 75 %
–
Select MEAS FUNC
®
Period
®
Single
®
A
–
Select
STAT
istics.
The result should be the clock period time mul-
tiplied by four, i.e. 4 x 648 = 2592 ± 2 ns
Standard Deviation
s
< 1 ns
Option 77
(-48 V
DC
from ext. source)
–
Disconnect the line power cord.
5-4 Rear Panel I/O
Performance Check