Tektronix 184, Инструкция по эксплуатации

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When circuit conditions are known to be safe, install
a tube or transistor of the same type which is known to
be good and check for proper operation. If the original
tube or transistor is thus proved acceptable, return it to
the socket from which it came to avoid unnecessary
reca I ibration.
Troubleshooting Aids
This manual and the instrument contain many features
intended to speed and simplify maintenance. A block dia­
gram which provides an overall picture of instrument
operation is included with the diagrams in the back of
this manual. The diagrams give the circuit reference num­
ber for each electrical component as well as important
operating voltages, signals, and conditions for their meas­
urement.
The instrument contains a number of stable metal-film
resistors identified by their gray background color and
color coding. If a resistor has th ree significant figures and
a mu ltiplier, it will be EIA color coded. If it has four sig­
nificant figures and a multipl ier, the value will be printed
on the resistor. For example a 333 kn resistor will be color
coded, but a 333.5 kn resistor will h ave its value printed
on the resistor body. The color coding sequence is shown
in Fig. 4-2.
Sig. Fig.
Sig. Fig.
Sig. Fig.
Tolerance
Date
Color
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
I
1 st 2nd
Sig. Sig.
Fig. Fig.
I
0 0
I
1
1
I
2 2
I
3
I
4
I
5 5
I
6 6
I
7 7
I
8
8
.
White
I
9 9
Gold
.
Silver
3rd
Sig. Mu ltipl ier
Fig.
0 1
1 10
2 100
3
1,000
I
4 10,000
I
5 100,000
6
1,000,000
I
7 10,000,000
I
8 100,000,000
I
1,000,000,000
0.1
I
0.01
Tolerance
(±) %
-
1
2
-
-
0.50
0.25
0.10
0.05
-
5
-
10
Fig. 4-2. Standard EIA color code for metal-film resistors.
®
Maintenance-Type 1 84
Color Coded to Type
Fig. 4-3. Diode polarity of the glass diodes used in the Type 184.
Fig. 4-3 identifies the polarity of the glass diode types
used in Tektronix instruments.
In-circuit diode checks.
In-circuit diode checks may be
performed with a voltmeter. A comparison check of the
voltages on each side of the diode with the typical voltages
listed on the diagram will help determine if the diode is
faulty. Forward-to-back resistance ratios can be checked by
referring to the schematic and pul ling appropriate tubes or
transistors to remove low resistance loops around the diode.
General Troubleshooting.
If the instrument is not operat­
ing, attempt to isolate the trouble by a quick operational
and visual check. Make sure that any apparent trouble is
actually due to a malfunction within the Type 184, and not
to improper control settings or a fault in associated equip­
ment.
Operate the front-panel controls to see what effect, if
any, they have on the trouble symptoms. The normal or
abnormal operation of each particular control helps in
establishing the nature of the trouble. The normal function
of each control is listed in Section 2 of this manual.
If the trouble cannot be located by means of front-panel
checks, remove the instrument from its case and check volt­
ages and waveforms against those shown on the schematics,
starting with the power supply connections. Once the trouble
is isolated to a particular circuit, refer to the circuit descrip­
tion in Section 3 for an explanation of how the circuit normal­
ly operates.
C
A U T
ION
Be careful when m a king measurements on l ive
circuits. The sm all size a n d high dens ity of com­
ponents used in this i nstrument resu
i
t in close
spacing. An in advertent movement of the test
probes, or the use of oversized probes, may sh ort
between circuits.
Troubleshooting Techniques
This troubleshooting procedure is arranged in an order
which checks the simple trouble possibil ities before proceed­
ing with extensive troubleshooting. The first few checks
assure proper connection, operation and cali bration. If the
trouble is not located by these checks, the remaining steps
4-3