. Various 160-161 Calibration Procedure free download

File name 160-161 Calibration Procedure.pdf

ISITIAL FACTORY TEST 6 ALIGN?!ENT PROCEDL7RE DBX MODELS lb0 AND 161 WITHOUT Ii47 & R39 (LATE 160 & 161) TEST EQUIWENT REQUIRED: QU_41\T l7-Y ITEM TYPE OR EQUIVALENT 1 Signal Oscillator Kron-Hite 4200, Heath 1272 1 Digital Multimeter Dana 3300, B & K 282, Digitec 2110 1 Oscilloscope Any (covering audio band) 1 . Wide Range db Deter DBX SK-C-1026, HP 427 1 Harmonic distortion meter DBX SK-B-1070, Heath lM58, HP330, GR1500, CR1900 1 + 3 db meter (cal_ref. 1 volt) DBX SKC-1071 (optional) 1 Resistor Substitution Box Any. k w 57. values, typically 10K to 4 7 0 K NOTE: On model 160, tie It - II terminals to Gnd, for normal testing. Revised 4-70-77 350325-03 DBX MODELS 160 - 161 INITIAL TEST OUTLINE SEQUENCE OF STEPS: 1) Supply Trim 2) RMS Trim 3) VCA & RMS Symmetry 4) Level Calibration 5) Threshold Calibration 6) Gain Change & input zero calibration 7) Output Calibration 8) Input Tracking g) Compression Circuit Calibration 10) (R78) Correct Value Test 11) Clipping 12) Response 13) Signal Clamping (Model 160 only) 14) Noise 15) Seal Pots 16) Burn-in . 350025-03 P-3 . 160/161 INITIAL PROCEDURE Before applying power to unit, check mechanical zero of meter. 1) Supply Trim: Put resistance substitution box across R14 and measure DC voltage at (+) side of C7. Turn sub box until voltage is +15 volts + 50 MV (+14.950 to + 15.050). Solder appropriate resistor in place. Check (-) side of C8 to verify that it is -15 volts - 200 MV + (-14.800 to -15.200) 2) RMS Trim: (205) Connect sub box across the two RMS trim pins, and measure the offset at the input pin of the RMS module. Trim the sub box until voltage is zero + 15 MV, and solder appropriate resistor in place. - 274) (209) With input of 1.228 VRMS at 100 Hz, place sub box between + v and the trim pin on the RMS module. Drop input level to - 60 db and adjust sub box until a symmetrical w