Tektronix 7A22, Instruction Manual

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Maintenance-Type 7A22
Areas
of
Repair
Input Coupling
switches and cables
Input Attenuators
Preamp
LF �3 dB POINT
TABLE 4-1
Checks
5
Adjustments
Calibration
Affected Step
---�"-''''--".--.--.. ''''-
.--." .. �-- .. --_.,-_." -----
Input R and C, 6, 13, 14, 15, 16,
Attenuator com- 17, 18, 19, 20,
pensation, CMRR, 21, 22
LF response, Gain
- ._. .
.
_. __ .
.
... _
.
... _--_ .. -
1
X
input C, Cross
Neutralization, DC
BAL, CMRR Com-
non-Mode dynam­
ic range, Differen­
tial dynamic range,
Offset range,
Noise, Input pro­
tection system
Gain, 1 MHz freq.
response, Over-
drive indicator
Ga-i�,TFf,:e
q . re-
sponse, 1 MHz
freq. response
3, 6, 10, 11, 12
13, 14, 20, 22,
23, 24
6, 20, 21
--
-
-'._-'. __ .
,"-"
... _ ....
-
Overdrive Indicator
---'_
..
_ .. _ .
.
__
.
.. _ ..
.
__ ._._-
-
-_._--_
..
__
..
_-
Gain Switched Amp
Dynamic range
---------,-.--�---..
-
-
-
------.-
-
.-.-.-..
--
Gain, Deflection
factor tracking, AC
Atten Bal, HF -3
dB POINT, 1 MHz
freq. response,
Overdrive recov­
ery Variable Bal-
ance
23, 24
1, 2, 6, 8
20, 26
-- -- -.- . .. --------�---.
.
. .
-... --.-. ------ --------..
Offset Generator Offset Range, DC 3, 22
Bal, CMRR
.. -"" -,._,,._._- _ .. ,--,,_.
-
._. __ . . " .. -----.... "-... ""-.-,.---.-.-----�-----
Output Amplifier HF --3 dB POINTS,
Var balance, Vari­
able range, Gain
Obtaining Replacement Parts
Standard Paris.
All electrical and mechanical part re­
placements for the Type 7 A22 can be obtained through your
local Tektronix Field Office or representative. However,
many of the standard electronic components can be ob­
tained locally in less time than is required to order them
from Tektronix, Inc. Before purchasing or ordering replace­
ment parts, check the parts lists for value, tolerance, rating
and description.
NOTE
When selecting replacement parts, it is important
to remember that the physical size and shape of
the component may affect its performance in the
instrument, particularly at high frequencies. All
replacement parts should be direct replacements
unless it is known that a different component will
not adversely affect instrument performance.
Special Parts.
Some parts are manufactured or selected
by Tektronix to satisfy particular requirements, or are manu­
factured for Tektronix to our specifications. These and most
4-2
mechanical parts should be ordered through your Tektronix
Field Engineer or Field Office. See Parts Ordering Informa­
tion and Special Notes and Symbols on the page immedi­
ately preceding Section 6.
Soldering Techniques
Circuit Boards.
Use ordinary 60/40 solder and a 35-
to 40-watt pencil type soldering iron on the circuit boards.
The tip of the iron should be clean and properly tinned
for best heat transfer to the solder joint. A higher wattage
soldering iron may separate the etched wiring from the
base material.
The following technique should be used to replace a
component on the circuit board. Most components can be
replaced without removing the board from the unit.
1. Grip the component lead with long-nosed pliers. Touch
the soldering iron to the lead at the solder connection. Do
not touch the soldering iron tip directly on the board, as
it may damage the board.
2. When the solder begins to melt, pull the lead out
gently. This should leave a clean hole in the board. If not,
the hole can be cleaned by reheating the solder and plac­
ing a sharp object, such as a toothpick or pointed tool,
into the hole to clean it out.
3. Bend the leads of the new component to fit the holes
in the board. Cut the leads of the new component to the
same length as those of the old component. Insert the leads
into the board until the component is firmly seated against
the board, or as positioned originally. If it does not seat
properly, heat the joint, and gently press the component
into place.
4. Apply the iron and a small amont of solder to the con­
nection to make a firm solder joint. To protect heat-sensitive
components, hold the lead between the component body
and the solder joint with a pair of long-nose pliers or other
heat si nk (see Fig. 4-l).
5. Clip the excess lead that protrudes through the board.
6. Clean the area around the soldered connection with
flux-remover solvent to maintain good environmental char­
acteristics and appearance. Be careful not to remove in­
formation printed on the board.
Fig.
4-1.
Removing or replacing component on circuit board.
01