HP 8568B MHz, MHz, MHz, C-1, Read, 100 Hz, 1. Press, SWEEP @iiYZ, Press MARKER, Equipment None required, ~8: 1, 30 kHz to 30 Hz bandwidths

5.6 dB Resolution Bandwidth Selectivity Test

Related Adjustments 3 MHz Bandwidth Filter Adjustments 21.4 MHz Bandwidth Filter Adjustments

Step Gain and 18.4 MHz Local Oscillator Adjustments

Specification 60 dB/6 dB bandwidth ratio:~11: 1, 3 MHz to 100 kHz bandwidths~8: 1, 30 kHz to 30 Hz bandwidths60 dB points on 10 Hz bandwidth are separated by ~100 Hz

Description Bandwidth selectivity is found by measuring the 60 dB bandwidth and dividing this value by the 6 dB bandwidth for each resolution bandwidth setting from 30 Hz to 3 MHz. The 60 dB points for the 10 Hz bandwidth setting are also measured. The CAL OUTPUT provides a stable signal for the measurements.

Equipment None required

Note Performance Test 4, 6 dB Resolution Bandwidth Accuracy Test, must be performed before starting this test.

Procedure	1. Press [		INSTR PRESET)		.
	2. Connect CAL OUTPUT to SIGNAL INPUT 2.
	3. Key in analyzer control settings as follows:
	[					)	.20	MHz
		C E N T E R F R E Q U E N C Y
							20	MHz
		FREQUENCY SPAN		.........................................]
	&?Ti, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .						.3	MHz
	@iEEDiJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .						100 Hz
	SWEEP @iiYZ-

4.Press MARKER C-1 and position marker at peak of signal trace. Press MARKER @ and position movable marker 60 dB down from the stationary marker on the positive-going edge of the signal trace (the MARKER A amplitude readout should be -60.00 dB +l.OO dB). It may be necessary to press SWEEP (CONT) and adjust CCENTER FREQUENCY_) so that both 60 dB points are displayed. (See Figure 4-4.)

5.Press MARKER (7iJ and position movable marker 60 dB down from the signal peak on the negative-going edge of the signal trace (the MARKER A amplitude readout should be .OO dB f0.50 dB).

6.Read the 60 dB bandwidth for the 3 MHz resolution bandwidth setting from the MARKER A frequency readout (Figure 4-4) and record the value in ‘Iable 4-4.

4-10 Option 462