Test 2-9: Total Harmonic Distortion (cont’d)
Example Program (cont’d)
230 PRINT "Connect Spectrum Analyzer to AFG Output. "
240 DISP "Press ’Continue’ when ready"
250 PAUSE
260 !
270 !---------- Set u p A F G ----------
280 OUTPUT @Afg;"*RST" !Reset AFG
290 WAIT 1
300 OUTPUT @Afg;"VOLT "&Dbm_out$ !Set AFG output
310 OUTPUT @Afg;"OUTP:FILT:FREQ 10MHZ" !Enable 10MHz filter
320 OUTPUT @Afg;"OUTP:FILT ON"
330 OUTPUT @Afg;"INIT:IMM" !Initiate
340 !
350 !---------- Per form test ----------
360 FOR I=1 TO 5
370 OUTPUT @Afg;"FREQ "&VAL$(Freq(I)) !Set frequency
380 !
390 CALL Meas_thd(Freq(I),Thd) !Measu re THD
400 PRINT "Fundamental Frequency =";Freq(I)
410 PRINT "THD =";DROUND(Thd,4);"dBc"
420 PRINT
430 DISP "Press ’Continue’ when ready"
440 PAUSE
450 DISP
460 NEXT I
470 !
480 OUTPUT @Afg;"*RST;*CLS" !Reset AFG
490 END
500 !
510 !
520 !---------- Measurement subprogram ----------
530 SUB Meas_thd(Frequency,Thd)
540 INTEGER Harmonic
550 CLEAR SCREEN
560 Harmonic=1
570 !
580 GOSUB Meas_fund !Get fundamental amplitude
590 !
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Agilent E1445A Service Manual Verification Tests 67