Adjustments - TB-9-6695-288-350008

TB-9-6695-288-35 Distortion Measurment Set Hewlett-Packardf Model 339A and 339A 001 Manual
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TB 9-6695-288-35

b. Adjustments

NOTE

Remove ratio transformer from equipment.

(1) Set INPUT RANGE switch to 3 V.

(2) Adjust calibrator output to 3 V and 1 kHz.

(3) Adjust A2R17 FULL SCALE ADJ (fig. 1) for TI meter indication of 3 V (R).

(4) Adjust calibrator output for 1 V.

(5) Adjust A2R37 1/3 SCALE ADJ (fig. 1) for a TI meter indication of 1 V on 3 V

range (R).

(6) Repeat (2) through (5) above for best in-tolerance condition.

(7) Connect multimeter to A2TP2 (fig. 1) and chassis ground.

(8) Adjust calibrator output to 3.162 V and 1 kHz.

(9) Adjust A2R36 REFERENCE ADJUST (fig. 1) for a multimeter reading of

3.162 V dc (R).

(10) Reduce calibrator output to 0.94 V ac.

(11) Adjust A2R35 LOW LIMIT ADJUST (fig. 1) until INPUT RANGE low limit

indicator (front panel) just lights (R).

(12) Increase calibrator output to 0.95 V ac. Low limit indicator should turn off. If

not, repeat (7) through (11) above.

(13) Set LINE switch to OFF.

(14) Disconnect cable connector from A2J2 (fig. 1). Place cable in a place that will

not short cable to chassis.

(15) Connect a jumper wire, using test lead between A2TP1 and A2TP8 (fig. 1).

(16) Connect multimeter between A2TP9 (+) (fig. 1) and chassis ground.

(17) Adjust output of calibrator to 3.0 V and 1 kHz.

(18) Set LINE switch to ON.

(19) Adjust A2R24 AUTO SET LEVEL FULL SCALE ADJ. (fig. 1) for an

indication of 3.162 V dc on multimeter (R).

(20) Reduce calibrator output to 1.0 V ac.

(21) Adjust A2R22 AUTO SET LEVEL 1/3 SCALE ADJ (fig. 1) for a multimeter

indication of 3.1612 V dc (R).