Corrective Maintenance; Parts Procurement - Tektronix 7a11 Instruction Manual

Wh e n
c
hec king the probable trouble area, associated
leads, switches and ot h er components should not be ig-
nored. Α
t
ransistor might be inoperative
b
ecause of α
d
efec-
tive resistor in series with it .
Th e c hart is designed on the
b
asis of single
d
efects.
M ulti p le p ro blems may disru
p
t the logic, but it should still
b
e effective in determining the
p
roblems, one at α time .
CO RRECTI VE MAI NTEN ANCE
Ge neral . Many electrical compone n ts are mounted in α
p
articular way to re
d
uce or control stray capacitance and
in
d
uctance . Dressing of lea
d
s an d orientation of
p
arts
should du plicate the original i nstallation .
WARNING
Disconnect the 7Α 11 from the Oscilloscope before re-
moving or replacing components.
Α
t
horough cleaning shoul
d
accom
p
any any repairs, and
α P
erformance Chec k or Calibration P
roce
d
ure should
b
e
satisfactorily
p
erforme
d
after the re
p
ai rs
h
ave
b
een com-
plete
d
.
P arts Procu rement
F
ig . 4-2. Color code for resistors and ceramic ca pacitors.
Maintenance-7A11
All parts use d
in this equi
p
ment can be purc hase
d
t
hroug h Te ktronix Field Offices or
R
e
p
resentatives . How-
ever, replacements for standar d
electronic items can
b
e
readily obtaine
d
from local electro n ic parts stores .
When selecti ng replacement parts, it is im p ortant to re-
member that the
p
hysical size an d
s
hape of α com
p
onent
may affect its performance at high frequencies . Α( Ι re
p
lace-
ment parts should be
d
irect replacements unless it is
k
nown
that α different com
p
onent will not adversely affect instru-
ment performance. Before
p
urchasing, cons ult the Electri-
cal
P
arts
L
ist to
d etermine the re quire
d
specifications .
Special Parts. Some electrical
p
arts are specially re-
worke
d
,
q
uality chec ke
d
, or manufactu re
d
to fulfill α parti-
c u la r re
q
uirement .
M
ost mechanical
p
arts are common to
t he s
p
ecific e
q
ui pment . All electrical
p arts wh ose part
numbers are
p
rece
d
ed by an asterisk, an
d
most mec hanical
p
arts, can therefore be obtained only throug h
t
h e Tek-
tronix Fiel
d
Office or
R
ep resentative . Or
d
ering i nformation
p
rece
d
es the Electrical
P
arts
L
ist.
Compositio n Resistors:
Ce ramic Capacitors:
an
d
3 Ο -1 st, 2n
d
and 3rd significant figur es ;
-multiplier;
Το -tolerance ;
TC -tem
p
erature coefficient.
R
esistor
a
n
d
Capacito r Colo r Code
*
For capacita nce of 10 pF
o
r less .
NOTE : Ο
a
nd /o r TC , colo r code fo r capacitors de pe nd s upon
ma nu factur er
a
nd capacitor type. May
n
ot be present in some cases.
4-5
Signifi-
Mu lti
p
lier Tolera nce
Color
ca nt
F
ig ures
R
esis-
_tors to
Ca
p
aci-1
rs
Ι
R
esis-
tors
Ca
p
aci-
to rs
Silver
10-2 Ι _ _
±10%
Gol
d
Ι
_ _ _
Ι 10 -1 Ι ---
±5%
B
lack 0
1 1 ---
±20% or
2 pF*
B
rown 1 10 10
-+1 % ±1 % or
0.1 pF *
R
ed Ι 2 Ι 102 10 2
±2% ( ±2%
O range 3 Ι_ 10 3 Ι 10 3 Ι ±3% Ι
±3%
Yellow 4 104 10 4 ±4 0/o
-χ-100%
-0%
G
reen 5 105 10 5 ± ρ.5 0 / o
±5% or
0.5 pF *
B
l ue 6 10° 10 5
___ ---
Violet
Ί
7
Ί -
Ι
--- ---
Gray
8 __-
1 ρ-2
___
+80%
-20%
or 0.25 pF *
Wh ite 9
---
10-1
---
_-L100/. or
1 pF *
(none)
---
F-7 _ _
±20 0
±10°/, or
1 p F*