HP 11848A Service Manual page 38

Installation
Model 11848A
A rear-panel, line power module permits operation from 100,120, 220, or 240 Vac. The number visible
in the window (located on the module) indicates the nominal line voltage to which the instrument
must be connected. Verify that the line voltage selection and the fuse are matched to the power source.
Refer to Figure 2, Line Voltage and Rise Selection.
Two fuses are supplied with each instrument. One fiise has the proper rating for 110/120 Vac line
operation (HP part number 2110-0063; 0.75A, 250V, non-time-delay). The other fiise is rated for
200/220 Vac operation (HP part number 2110-0012; 0.5A, 250V, non-time-delay).
One fuse is installed in the instrument at the time of shipment. The rating of the installed fuse is
selected according to the line voltage specified by the customer. If the voltage is not specified, the
rating of the installed fiise will be selected according to the country of destination.
|WARNING|
For protection against fire hazard, the line fuse should only be a 250V
normal blow fuse with the correct current rating.
Power Cables
|WARN1NG|
BEFORE CONNECTING THIS INSTRUMENT, the protective earth
terminal of the instrument must be connected to the protective conductor
of the (mains) power cord. The mains plug shall only be inserted in a
socket outlet provided with a protective earth contact. The protective action
must not be negated by the use of an extension cord (power cable) without
a protective conductor (grounding). Grounding one conductor of a two
conductor outlet is not sufficient protection.
This instrument is equipped with a three-wire power cable. When connected to an appropriate ac power
receptacle, this cable grounds the instrument cabinet. The type of power cable plug shipped with each
instrument depends on the country of destination. Refer to Table 2 on for the part numbers of the
power cables and Mains plugs available.
Mating Connectors
Coaxial Connectors. Coaxial mating connectors used with the Phase Noise Interface should be either
the 50-ohm BNC male connectors or 50-ohm Type-N male connectors that are compatible with those
specified in US MIL-C-39012.
The application note, "Principles of Microwave Connector Care" (HP part number 5958-7442) can help
you improve measurements and reliability. Suggestions in the application note will help you get the best
performance from all microwave connectors. It will show what to look for when cleaning and inspecting
connectors (in order to preserve their precision and extend their life) and how to make the best possible
microwave connections (improving the accuracy and repeatability of all your measurements).
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