Sect. IV Page 1
SECTION IV
MAINTENANCE
4-1 GENERAL INFORMATION 9) A frequency response generator such as an @
Specification 23679.
This section contains instructions for testing, ad-
justing and trouble-shooting the Model 150A Oscil-
loscope. If the instrument is operating, the Con- 4-2 ROUTINE SERVICING
densed Test and Adjustment Procedure, paragraph
4-3, is a fast method of checking the basic adjust- Routine servicing covers air filter cleaning, cabinet
ments and operation. The Trouble-Shooting Proce- removal, adjustments required when tubes are
dure, paragraph 4-4, is a rapid means of isolating changed, and CRT replacement.
a section of the instrument that is not functioning.
Paragraph 4-2 deals with the physical layout of the Each of the major sections of the instrument is lo-
instrument and routine maintenance procedures. cated in a particular area. Figure 4- 1 indicates the
location of these sections. The Horizontal Ampli-
Schematic Diagrams and the Table of Replaceable fier and the Sweep Generator and Sync Amplifier
Parts are located at the end of this section. sections will swing out when the instrument is out
of the cabinet. These sections are held in place by
The following test equipment is used for testing and fasteners near the panel.
adjusting the Model 150A Oscilloscope during manu-
facture. Equivalent test equipment may be used.
A. CLEANING THE AIR FILTER
1) A test oscilloscope such as the @ Model 150A
equipped with an @ Model 152 Dual Trace Ampli- Inspect the air filter often when the Oscillo-
fier. scope is in constant use.
2) A high impedance dc vacuum tube voltmeter cal- The air-filter element in the 150A is a reuseable
ibrated to an accuracy of A%, such as an @ Model type. It is located in the bottom of the instrument
410B with an @ Model 459A DC Voltage Mcitiplier. cabinet and is removed by pulling straight down. In
the rack mount pull the filters to the rear. To clean
3) A high impedance ac vacuum tube voltmeter, the filter element, wash in warm water and deter-
such as an @ Model 400D/WL. gent, then recoat with an adhesive made for this
purpose. Filter Coat No. 3 made by Research Pro-
4) A variable power line transformer with a mini- ducts Corp., Madison 10, Wisconsin is suitable. If
mum rating of 7.5 amps, equipped with a voltmeter, you have difficulty obtaining it, see your Hewlett-
accurate within 1 volt. Packard Field Sales Engineer.
5) A square wave generator such as an $3 Model Apply Filter Coat No. 3 with the HANDIKOTER spray
211A. applicator directed at the intake side of the filter
until visible baffles are liberally coated. Do not
6) A sine wave o scillator with a m aximum frequency spray to the extent that adhesive runs or drips off
of at least 50,000 cycles, such as an @ Model 200CD. the surface of the filter. Filter is now ready for
service.
7) An accurate time mark generator suitable for B. REMOVING THL CABINET
sweep speed calibration.
CAUTION
8) A voltmeter calibration generator such as an @ When the cabinet is removed, dangerous voltages
Specification 23678. are exposed. Observe adequate safety precautions.
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ACEC
