![](/images/backgrounds/286910/hp-e4401b-users-manual-54883328x1.png)
Front and Rear Panel Features
Front Panel Overview
frequency span are GHz, MHz, kHz, and Hz, whereas the units for reference level are +dBm, − dBm, mV, ∝ V, and ∝ A.
NOTE If an entry from the numeric keypad does not coincide with an allowed function value (for example, that of a 12 MHz bandwidth), the analyzer defaults to the nearest allowable value.
| The Step Keys (⇓ ⇑ ) increase or decrease the active function value. The step |
| size depends upon the current analyzer measurement. Each press results in |
| a single step change. For those parameters with fixed values (resolution |
| bandwidth), the next value in a sequence is selected each time a step key is |
| pressed. Step size is predictable (e.g., 10% of span for center frequency) and |
| can be set for some functions (i.e., center frequency). |
| |
11 | VOLUME. The VOLUME knob adjusts the volume of the internal speaker. The |
| speaker is turned on and off with the Speaker On Off key in the Det/Demod menu. |
12 | EXT KEYBOARD. The EXT KEYBOARD connector is a |
| The keyboard can be used to enter screen titles and filenames. |
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NOTE | To avoid damage to the analyzer, always turn off power before plugging a keyboard |
| into the analyzer. |
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13 | PROBE POWER provides power for |
| accessories. (+15 V, − 12.6 V, 150 mA maximum) |
14 | LO OUTPUT provides the proper local oscillator signal for use with external |
| mixers (Option AYZ). |
15 | IF INPUT connects to the IF OUTPUT of the external mixer (Option AYZ). |
16 | Return. The Return key accesses the previously selected menu. Continuing to |
| press Return accesses earlier menus. Return also terminates entry of alpha |
| numeric functions (e.g., Title). |
17 | AMPTD REF OUT provides an amplitude reference signal of 50 MHz at |
| Agilent ESA models E4402B, E4403B, E4404B, E4405B, E4407B, and E4408B |
| only. |
18 | Tab Keys are used to move around in the Limit editor, the Correction editor and |
| similar |
19 | INPUT 50Ω (INPUT 75Ω for Option 1DP) is the signal input for the analyzer. |
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| CAUTIONWhen operating in dc coupled mode on analyzers with Option UKB, |
| ensure protection of the input mixer by limiting the input level to |
| 0 Vdc, +30 dBm. |
| When operating in ac coupled mode, ensure protection of the |
| input mixer by limiting the input level to 50 Vdc, +30 dBm. |
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20 | The Next Window key can be used to select the active window in functions which |
| support |
| the User’s guide for more information.) In such modes, pressing Zoom switches |
28 | Chapter 2 |