Tektronix 485 User Manual

Calibration—485/R485 Service
b. Adjust for best response.
Four of five upper
adjustments in the MAIN
VERT TRANS RESPset
(all but C617 next to
the 1C).
R613
R614
R615
Adjust for best flat
top response.
Slug-tuned coil near
the output 1C.
L654 Best flat top
response.
CH 1 adjustments above
U210.
C214
R214
Best front corner
level.
CH 1 adjustments behind
U210.
C240
R240
Fastest Risetime.
CH 2 adjustments above
U310.
C31 5
R315
Best front corner
level.
CH 2 adjustments behind
U310.
C340
R340
Fastest Risetime.
Uppermost adjustment
in the MAIN VERT
TRANS RESPset.
C617
Minimum ringing
and fastest risetime
for CH 1 and CH 2.
NOTE
U510 and U530 may be raised part way out o f their
sockets to match the level o f the first 3 ns to the
remainder o f the waveform for CH 1 and CH 2
transient response respectively.
63. ADJUST 1 M£2 DC BAL CH 1 and CH 2
NOTE
<
These adjustments are accessible at the bottom o f the
instrument.
a. Input to 50 £2; VOLTS/DIV to 5 mV; VERT MODE
to CH 1; input to GND.
b. Switch to 1 M£2 and adjust R45 for 0 shift between
50 £2 and 1 M£2.
64. CHECK 1 M£2 GATE CURRENT CH 1 and
CH 2
Switch from GND to DC in 5 mV; check for 0.2 div or
less of shift.
65. ADJUST 1 M£2 AMPLIFIER GAIN CH 1 and
CH 2
NOTE
Adjustments are labeled on the bottom shield o f the
attenuator compartments.
a. Set VOLTS/DIV to 20 mV.
b. Apply 100 mV from Amplitude Calibrator and Com
parator, then adjust R78 for 5 div of deflection.
c. Check 50 £2/1 M£2 gain match ;±1% in 20 mV/div.
66. ADJUST 1 MO 10 kHz TRANSIENT RE
SPONSE, CH 1 and CH 2
a. Connect Type 106 High Amplitude with 6 div of
10 kHz through 5X attenuator, GR cable, 50 £2 termi
nation.
b. Adjust C46 and R53 for optimum response.
67. ADJUST 1 M ft INPUT ATTENUATOR COM
PENSATIONS, CH 1 and CH 2
a. Connect 5 div of 1 kHz from Type 106 High Ampli
tude, through 5X and 10X attenuators, a 50 ohm termi
nation, and 20 pF standardizer. Volts/Div to 20 mV.
b. Adjust Cl 2 for front corner level to match 50 £2
input level. (Remove 20 pF standardizer, then check 50 £2
input level with 50 £2 pushbutton depressed.)
c. Check 5, 10, and 50 mV.
d. Set VOLTS/DIV to 100 mV (knob setting .IV),
remove the 5X attenuator, and adjust C24 and C26 for
optimum response.
e. Check 200 and 500 mV.
f. Set VOLTS/DIV to 1 V (remove 10X attenautor and
50 £2 termination) and adjust C20 and C22 for optimum
response.
g. Check 2 and 5 V.
REV. C, SEPT. 1974
5-19

Tektronix 485 Specifications

General

Brand	Tektronix
Model	485
Category	Test Equipment
Language	English