Tektronix 491 - Page 6

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INSTRUCTIONS: (Cont
1
d)
E. TO REPLACE CONNECTOR CIRCUIT BOARD
( ) l. Unsolder all of the wires from the pin connector circuit board on the
Phase lock chassis and replace the connector circuit board with the new
Connector circuit board, from the kit, and wire as follows:
--
Pin
Wire Color Pin
Wire Color
----·
A
white
and #22 bare
E*
white-black
wire to pin B
F white-brown-red
B
Shield for pins G
white-brown-green
C & D
H
white-black-brown
c Red
I*
white-vi o 1
et
D Black
J*
white-blue
F. TO REPLACE OSCILLATOR CONNECTOR BOARD. SEE FIG. 1
( )
1. Unsolder all of the wires from the oscillator connector circuit board.
( )
2. Remove the oscillator circuit board mounting screws and replace the
circuit board with the new board and wire as follows:
( ) 3.
Solder the White-red wire (See Ftg. 1) to the -20VDC termina1 on the
Band
11
C
11
osci1 lator.
( ) 4. Solder the white wire from the ground connection on the Band
11
C
11
oscillator to the grounded** side of the Band
11
B
11
filament.
( ) 5.
Solder the white-black wire from the AFC terminal on the Band
1
C
1
oscillator to the AFC terminal on the Band
1
B
1
oscillator.
( ) 6. Connect the remaining wires as shown in the drawing.
FIGURE 1.
WHT-BLK--
* The white-black, white-violet, and white-blue wires will be connected in
step G 4-6.
** Terminal toward the back. CHECK WITH OHMETER TO BE SURE.
Page 6 of 9 050-0692-02