9.3 dB Bandwidth Adjustments

Reference

Related Performance Test

Description

Note

IF-Display Section

A4A9 IF Control

Resolution Bandwidth Accuracy Test

The CAL OUTPUT signal is connected to the RF INPUT. Each of the adjustable resolution bandwidths is selected and adjusted for the proper bandwidth at the 3 dB point.

Do not perform this adjustment on Option 462 instruments. Option 462 instruments require a different procedure. Adjustment 9 for Option 462 (6 dB or Impulse Bandwidth) is located in Chapter 4, Option 462.

Equipment

Procedure

No test equipment is required for this adjustment.

1.Position instrument upright and remove top cover.

2.Set LINE switch to ON and press (INSTR PRESET].

3.Connect CAL OUTPUT to RF INPUT.

4.Key in [CENTER FREQUENCY_) 20 MHz, (FREQUENCY SPAN) 5 MHz, LIN,

and (REs] 3 MHz.

5.Press PREFERENCE LEVEL] and adjust DATA knob to place signal peak near top CRT graticule line. Signal should be centered about the center line on the graticule. If not, press (PEAK SEARCH) and QEXTTF).

6.Press MARKER a.

7.Using DATA knob, adjust marker down one side of the displayed signal to the 3 dB point; CRT MKR A annotation indicates .707 X.

8.Adjust A4A9R60 3 MHz for MKR A indication of 1.5 MHz while maintaining marker at 3 dB point (.707 X) using DATA knob. See Figure 3-45 for location of adjustment.

3-84 Adjustments