14
2005

CAUTION

THIS TEST IS NOT RECOMMENDED FOR HIGH FREQUENCY
OR LOW CURRENT DEVICES IN OTHER INSTRUMENTATI0N,
AS CURRENTS FROM S0ME OHMMETERS MAY BE SUFFICIENT
TO DAMAGE SMALL SEMICONDUCTOR JUNCTIONS.

To test a component located in the oven:

(1)
Unplug the line cord and remove the cover from
the power supply.
(2)
Loosen the three screws which secure the oven cover.
(3)
Rotate the cover counterclockwise and pull it away
from the oven.

(4)
Remove the two screws which secure the oven cap;
then remove the cap.

(5)
Reach into the oven and extract the oven board.
NOTE

To test the oven board while the unit is operating, remove
it from its socket and insert a test adapter (Vector
Electronic Corp. Type P-9-N-S, or equal) in its place.
The board can then be plugged into the adapter.

(6)
To reassemble the oven, replace the board and cap.
Secure the cap in position with two screws. Slide the oven cover down until the screws slide into the slots in the cover. Turn the cover clockwise and tighten the three screws.

e. Poor Regulation, High Ripple: No specific check can be suggested since failure to regulate within specifications may be caused by any of the components in the supply. Make a point-to-point voltage and resistance chock. Check all capacitors for open circuits and all electrolytic capacitors for excessive leakage. Make stage—gain measurements by changing the output load current and noting the change in base current of each amplifier stage. Use low resistance milliammeters and microammeters to avoid upsetting the regulator. The open—loop current gain of the regulator should be more than 106 from the base current of the input differential amplifier to the collector current of the series regulator.


645
4—4

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