Tektronix 575 122C Manual

OPY 391262
575 MOD L226
FOR CUSTOM INSTRUMENTS
Start with the instrument upside down.
Using CSB as a base for the jig, center punch and then drill (4) 5/3a
holes, that would be a #23 bit. See sketch.
Remove the nut of the mounting screw on C243, nearest the sub-panel, and
mount a #6 solder lug facing the front.
(3) wires, (2) 9-4 wires and (1) 3-N wire are laced together from the
grommet and main cable. They are loose at this time. Remove the lacing
and re-tie at the main cable to prevent unraveling. 7
Remove both (2) 9-4 wires. (1) is a short wire that would run from CSB4
to the toggle switch on the front porch. The other is a long wire that
would run from CSB4 to the Horiz. Volts/Div. switch.
Do not connect the 3-N wire at this time.
Add two (2) four slot strips in the holes that were previously drilled.
see sketch.
Remove the large varible cap (C735) and straps.
Rewire the strips as follows:
3 A47pf cer. cap from CSA4 to CSB4 tects}
2) 1 meg 1/2w 1% from CSA4 to CSB4 (delete
CSA3 to CSB3 (delete)
(1) Mica Cap from CSAl to CSB1 (delete)
(1) LOK lw 10% from CSA2 to CSB2 (keep to be used again later)
B. Move:
1) -150 wire from cable to CSB2 to CSB1
1) Strap from pin 1 of V733 to CSA4 to CSB3
C. Add:
(1) #20 strap from CSA4 to CSB4
1) 300K 4/2w 1% from CSA% to CSB2
1) .002 ufd mica cap from CSA2 to CSB2
(1) 10K lw 10% from CSAl to CSB1 (same resistor as was