HP 8719ET Reference Manual page 109

4. KEYBOARD input (mini-DIN). This connector allows you to connect an
external keyboard. This provides a more convenient means to enter a title
for storage files, as well as substitute for the analyzer's front panel
keyboard.
5. Power cord receptacle, with fuse. For information on replacing the
fuse, refer to the installation and quick start guide.
6. Line voltage selector switch. For more information, refer to the
installation and quick start guide.
7. Fan. This fan provides forced-air cooling for the analyzer.
8. 10 MHZ PRECISION REFERENCE OUTPUT. (Option 1D5)
9. 10 MHZ REFERENCE ADJUST. (Option 1D5)
10. EXTERNAL REFERENCE INPUT connector. This allows for a
frequency reference signal input that can phase lock the analyzer to an
external frequency standard for increased frequency accuracy.
The analyzer automatically enables the external frequency reference
feature when a signal is connected to this input. When the signal is
removed, the analyzer automatically switches back to its internal
frequency reference.
11. AUXILIARY INPUT connector. This allows for a dc or ac voltage input
from an external signal source, such as a detector or function generator,
which you can then measure, using the S-parameter menu. (You can also
use this connector as an analog output in service routines, as described in
the service guide.)
12. EXTERNAL AM connector. This allows for an external analog signal
input that is applied to the ALC circuitry of the analyzer's source. This
input analog signal amplitude modulates the RF output signal.
13. EXTERNAL TRIGGER connector. This allows connection of an
external negative-going TTL-compatible signal that will trigger a
measurement sweep. The trigger can be set to external through softkey
functions.
14. TEST SEQUENCE. This outputs a TTL signal that can be programmed
in a test sequence to be high or low, or pulse (10 µseconds) high or low at
the end of a sweep for robotic part handler interface.
Front/Rear Panel
Rear Panel Features and Connectors
3-11