Test The Ttl Threshold - HP 1660 Series Service Manual

Testing Performance
To test the threshold accuracy (logic analyzer)

Test the TTL threshold

Press the Format key. Select the field to the right of Pod 1, then select TTL in the
1 1
pop-up menu.
On the function generator front panel, enter 1.750 V ± 1 mV DC offset. Use the
2 2
multimeter to verify the voltage.
The activity indicators for pod 1 should show all data channels and the J-clock channel at a
logic high.
Using the Modify down arrow on the function generator, decrease offset voltage in
3 3
1-mV increments until all activity indicators for pod 1 show the channels at a logic
low. Record the function generator voltage in the performance test record.
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