6. Sampling Oscillator Adjustment

23.Set the HP 6114A Power Supply for a 21 Vdc output 50.2 lead to X201 pin 1 and the negative supply lead to X201 pin

V. Connect the positive supply 4.

24.Connect the active probe to TP201.

25.Set the HP 8560A [LINE] switch on and set the controls as follows:

C E N T E R F R E Q . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..661MHz SPAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 Hz

26. Set the HP 5343A Frequency Counter as follows:

SAMPLE RATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Counterclockwise

50R--MO SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500

10 Hz-500 MHz/500 MHz-26.5 GHz SWITCH . . . . . . . . . . . 10 Hz-500 MHz

RESOLUTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 kHz

27.Starting at the end of 2200 nearest X201, short the center conductor to a hole in the ground plane with the lead of a 1 MR resistor (HP part number 0757-0059) until the frequency counter reads 298 MHz f4 MHz.

28.Once the proper tap has been found, solder the resistor lead to the ground plane and the center conductor of 2200. Cut away the rest of the resistor.

29.Remove the power supply leads and the active probe.

30.Set the HP 8560A (LINE) switch off and reinstall the top shield. Set the m switch on.

31.Repeat the procedure beginning at step 2 for the remaining center frequencies listed in Table 2-11.

Table 2-l 1. Sampling Adjustments

511288

541290

571292

601294

631296

661298

2-36 Adjustment Procedures