Sect. IV Page 1
SECTION IV
MAINTENANCE
4-1 IN TRODUCTORY APPLICATION EQUIPMENT
This sel ction contains instructions for maintaining Power supply ad just - 20,000 ohm/volt multi-
and fro1 uble shooting the Model 500B as well as ment; dc voltage and meter or dc VTYM,
procedu res for tube replacement and internal ad- resistance measure- suchas -hp- Model
ment. 410B. t. A tube replacement chart describes ad-
justmenl
justmen ts necessary after tube replacement, and a
Range calibration and Accurate test oscil-
trouble shooting chart contains procedures for
phantastron adjust- lator to 100 KC with
checking g instrument performance section by sec-
ment. at least 10 volt signal
tion to assist in localizing most troubles which
output, such as -hp-
may occ ur.
200 series.
COMPR: EHENSIVE CHECK
Signal tracing. AC VTVM, wide fre-
quency range, such as
After y 'ou replace tubes or otherwise restore
-hp- Model 400 series.
instrumc ent to operation you may want to make a
completc e check for optimum performance. If this
is the c aSe, perform the procedures given in the 4-4 TUBE REPLACEMENT
) referenc :e paragraphs below in the followingorder:
Tubes used in the Model 500B are listed in
Para .graph 4-8 Table 4-1, following. A tube may be replaced
Para graph 4-6 with any tube of its type having standard charac-
Chec :k waveforms in Figure 4-6 teristics. The tubes which involve circuit ad-
justment when replaced are accompanied by a
Para graph 4-9 reference to the applicable paragraph in this
Para .graph 4-11 section of the manual.
Para graph 4-10
4-5 TROUBLE LOCALIZATION
4-2 CA ABINET REMOVAL
The conservative design of the Model 500B means
To remc ove the instrument from the case, remove that normal aging has little effect on operation.
two mal chine screws from the rear of cabinet. Tube replacement and adjustment should repair
Full frc ont panel forward from the case. (The the majority of difficulties which may develop in
bezel rr emains attached to the front panel of the the instrument. Isolation of circuit failures is
instruml frequently possible by considering the sections, ent.)
shown in Figure 3-1, and observing the effects
of front panel controls on instrument behavior.
4-3 E( SUIPMENT REQUIRED Electrical trouble shooting should be preceded with
a visual inspection. Look for signs of damage,
Test prc ocedures in this section attempt to isolate burned out components, overheating, or loose-
ness of parts which, if not failure sources them-
as man: y probable difficulties as possible with a
minimui n of equipment. The nature of the in- selves, suggest areas of future trouble. A cold
strumen ,t, however, requires the following equip- tube found simply by touch may save considerable
ment to be available. time and effort in restoring the instrument to |
ACEC
