HP TM 11-6625-2779-14&P manual Adjustment and Calibration Procedure, Power Supply Check

Section V

CARRIER 600 and repeat the above procedure. Between 1kHz and 10kHz, the balance must be greater than 70dB. Between 10kHz and 100kHz, the balance must be better than 60dB. Between 100kHz and 600kHz, balance must be better than 40dB.

5-14. ADJUSTMENT AND CALIBRATION PROCEDURE.

5-15. The following is a complete adjustment and calibration procedure for the Model 3555B. These adjustments should be performed only after it has been determined by the performance checks that the set is not operating within its published specifications.

5-16. POWER SUPPLY CHECK.

5-17. Before attempting the following calibration procedures, first check the power supply voltage to be sure that it is correct and that the ripple voltage is not abnormal. To do this perform the following steps.

NOTE

Calibration of the 3555B should be performed with the set operating from the internal battery except for the power supply ripple check in the following steps. Operate the set from the ac power source long enough to make this check and then return the set to internal battery operation. This is accomplished by changing the position of the slide switch mounted on the side of the set. When operating from the battery, disconnect the ac power cord from the set.

a.Remove the set from the case and connect the 3440A/3445A dc voltmeter between the - 20V supply and ground. The negative side of A3C34 is a convenient place.

b.Turn the set on. The 3440A/3445A should indicate -20 volts ±1.0V.

c.Connect the 400FL AC Voltmeter to the negative side of A3C34 and measure the ripple voltage. The maximum allowable ripple is 200uV rms.

5-18. 75 UNBAL CALIBRATION.

a.Connect the 654A and 3440A/3445A as shown in Figure 5-2and set the 3555B controls as follows:

FUNCTION ................ 75 UNBAL INPUT..................... TMS, TERM RANGE ..........................+10dBm

b.Set the 654A frequency to 10 kHz, 75 UNBAL, and adjust the output level for 866 mV (+ 10 dBm) indication on the 3440A/3445A.

Model 3555B

c.Set the 654A meter for a reference indication and be sure to maintain this indication throughout the following procedures unless

otherwise instructed. Disconnect the 3440A/3445A voltmeter.

d.Change the 654A to -50dBm and change the 3555B RANGE switch to -50dBm.

e.Disconnect the 3440A/3445A, the 11094A termination and the cable. Connect the 654A output directly to the 3555B input.

f.Adjust A3R43 for 0dBm indication on the 3555B meter.

g.Change 654A frequency to 3MHz maintaining the reference established on the 654A meter.

h.Adjust A3C8 for 0dBm indication on the 3555B meter.

5-19. ATTENUATOR CALIBRATION.

a.Remove the FUNCTION board and replace it with the test board supplied with the set.

b.With the equipment and controls set as in the preceding check, change the 3555B RANGE to 40dBm and change the 654A attenuator to -40dBm. Change the 654A frequency to 100kHz.

c.Adjust A2C12 for 0dBm indication on the 3555B meter.

d.Change the 3555B RANGE switch to -30dBm and change the 654A attenuator to - 30dBm. Adjust A2C7 for 0dBm indication on the 3555B meter.

e.Change the 3555B RANGE switch to -20dBm and change the 654A attenuator to - 20dBm. Adjust A2C4 for 0dBm indication on the 3555B meter.

f.Change the 3555B RANGE switch to +10dBm and change the 654A attenuator to +10dBm. Adjust A2C1 for 0dBm indication on the 3555B meter.

g.Check the frequencies listed in Table 5-2for the tolerance indicated. If any of the checks in Table 5-2do not meet the indicated tolerances, repeat steps b through f.

5-20. FUNCTION CALIBRATION.

a.Remove the test board from the set and install the function board assembly. Connect the 654A balanced output to the 3555B balanced input terminals. See Figure 5-5.Set the 3555B controls as follows:

FUNCTION........ CARRIER, 600 BAL INPUT ........................... TMS, TERM RANGE ................................ -50dBm

b.Set the 654A frequency to 10kHz and adjust the output attenuators for -5OdBm output level, using the 600 BAL output function.

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