ADDENDUM

I. Generally Applicable Annotations

Consistent with good engineering practice, leads attached to customer accessible signal/monitoring ports (such as the l0-pin Control Connector, the 7-pin Analog Connector, the 7-pin Digital Port/Trigger Connector, screw terminal Barrier Blocks, etc.) should be twisted and shielded to maintain the instrument's specified performance.

II. CE'92 Product Specific Annotations

When tested for radiated susceptibility as called for in EN 50082-1 per the EC EMC directive, the following changes in the Supplementary Characteristics of the 6621A and 6623A have been noted:

6621A

When subjected to radiated field strengths of 3 volts/meter in the vicinity of 90 MHz, the full scale programming accuracy of channel 2 increases from 31 millivolts at 20 volts output to 700 millivolts.

The accuracy reverts to the published value of 31 millivolts when the field is reduced to 2 volts/ meter.

When subjected to radiate field strengths of 3 volts/meter in the vicinity of 200 MHz, the full scale readback accuracy of channel 1 increases from 23 millivolts at 5 volts output to 100 millivolts.

The accuracy reverts to the published value of 30 millivolts when the external field is reduced to 2 volts/meter.

6623A

When subjected to radiated field strengths of 3 volts/meter in the vicinity of 160 MHz, the full scale programming accuracy of channel 1 increases from 31 millivolts at 20 volts output to 50 millivolts.

The accuracy reverts to the published value of 31 millivolts when the field is reduced to 2.5 volts/ meter.

When subjected to radiate field strengths of 3 volts/meter in the vicinity of 160 MHz. the full scale readback accuracy of channel 1 increases from 30 millivolts at 5 volts output to 50 millivolts.

The accuracy reverts to the published value of 30 millivolts when the external field is reduced to 2.5 volts/meter.

114 Addendum