Tektronix 2A60 Instrument Reference Book page 46

INPUT AMPLIFIER CH A NGES
REDUCE COMPRESSION WITII
VARIABLE VOLTS/DIV IN
COUNTER-CLOCKWISE POSITION
Effective Prod SN 3044
w /exceptions: 3041-2
See SQB MJ 0303-1
Usable in field instruments SN J OJ -3043
FRONT PANEL SYMITOM: Noticeable compression when the VARIABLE VOLTS/DIV is
ccw and the POSITION control is used to buck out signal DC level of greater thon
2 or 3 divisions.
PROBLEM: The suppressor grids of V434 and V444 were returned to ground and the plotc
voltage was not adequate
to
handle input signal swings of more than ±1. SV from
ground (±3 divisions when the VARIABLE VOLTS/DIV was ccw).
PRODUCTION CHANGE: The suppressor grids of V434 and V444 were connected to their
respective cathodes and the plate voltage was increased by about JO volts by changing
R432 from 5.25k l/2W 1%
to
4.225k l/2W 1%. These changes reduce the gain
change to less than 2%. See Mll214.
Parts Removed: Res, prec, 5.25k l/2W 1%
Pc1rts Added:
R432
R432 Res, prec, M. F., 4. 225 k l/2W 1%
309-00:32-00
323-0663-00
INSTALLATION INSTRUCTIONS:
Ports r~cquired:. See 'Parts Added. '
In staJla tion Procedure:
Replace R432, a 5. 25 k 1 /2W J % resistor located
between CSA -5 and CSB-5 with a 4. 225 k l /2W l %
resistor. See drawing.
C':,A
Page JO 60/2A60 MODIFICATION SUMMARY
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