Heathkit Model EU-80A

Voltage Reference Source

 

Date Calibrated:   _____/_____/_____

 

Calibration Procedure

 

Ancillary Equipment Needed

 

EU-805A Universal Digital Voltmeter

(or equivalent)

 

* * * * * * *

NOTES

·         Remove all jumper wires between the circuit grounds and chassis ground.

 

·         Remove all loads from both sets of terminals.

 

·         Use of non-metallic alignment tools is preferable.

 

·         A very accurate voltage measurement device must be used if the Voltage Reference Source should require recalibration.

 

* * * * * * *

Initial Front Panel Adjustments

 

(    )         Remove the plug button from the Calibrate hole in the rear panel of the unit.

 

(    )         Disconnect the shorting bar between the common ground and the chassis ground output binding posts.

 

(    )         Connect the line cord to the AC line voltage.

 

(    )         Set the left most pushbutton to the ON (in) position.

 

(    )         Allow the unit to stabilize for at least 30 minutes.

 

(    )         Set all four right pushbuttons to the OUT position.

 

(    )         Connect a set of test leads from the Digital Voltmeter input to the OUTPUT terminals of the unit (observe correct polarity).

 

(    )         Connect a test lead from the chassis ground of the unit to the chassis ground on the Digital Voltmeter.

 

(    )         Set the Digital Voltmeter to indicate 10-volts on the lowest scale.

 

(    )         Set the first switch to the nine (9) position.

 

(    )         Set the second switch to the nine (9) position.

 

(    )         Adjust the third switch to the ten (10) position.

 

(    )         Set the fourth switch to the volts (V) position.

 

(    )         The left most decimal point should be lighted.

 

* * * * * * *

 

(    )         Adjust the Calibrate control (rear chassis) using an insulated screwdriver until the Digital Voltmeter indicates 010.000 volts.

 

(    )         Set the left most pushbutton to the OFF (out) position.

 

(    )         Disconnect all external components from the front terminals.

 

(    )         Disconnect the line cord from the AC line source.

 

(    )         Replace the plug button into the Calibrate hole in the rear panel of the unit.

 

(    )         Calibration procedure is complete.