TM 11-6625-2965-14&P

APPENDIX D

MANUAL BACKDATING CHANGES

Manual backdating changes describe changes necessary to adapt this manual to earlier instruments. T O adapt the manual to serial numbers prior to 7L2301 inspect the following table for your serial number and then make the appropriate changes. For serial numbers 7L4450 and up check for inclusion of change sheet.

CHANGE 1:

In the replaceable parts table, make the following changes:

Delete

Q10.

 

 

 

Delete

R51.

 

 

 

Change

R53

to

fxd, comp 10

±5% ½W, EB-1005,

0 1 1 2 1 ,

p a r t N o . 0 6 8 6 - 1 0 0 5 .

Change

R54

to fxd, ww 5.25

±0.5% ½W, Type

E-30,

01686,

Part No, 0811-1921.

Change R81 to var. ww 100

, Type 110-F4,

11236,

Part

No. 2100-0281.

On the schematic remove transistor Q10 in current limit circuit and connect circuit as shown in

Figure B-1.

The circuit description Paragraph 4-19should now read as follows:

4-19 Current limiting occurs when diode CR16 becomes forward biased. Its anode potential is determined by the voltage at the base of Q4. The cathode potential of CR16 is determined by the voltage drop acress resistors R53 and R81

Figure B-1.

which, in turn, are connected across the current sampling resistor(s). The cathode potential of CR16 is a function of the output current.

A S this current increases, the drop across the sampling network increases, and CR16 will start to conduct. Conduction of this diode clamps the base of Q4 to a potential which decreases the conduction of the series regulator, thus limiting the output current, Potentiometer R81 permits the cathode potential of CR16 to be varied and thus charges the current limiting threshold.

Paragraph 5-52,Step (e) should read:

“Adjust R81 until differential voltmeter indicates 2.55 Vdc . . . .”

D-1