TM 55-4920-390-13&P
SECTION VIII
INTRODUCTION TO PARTS LISTS AND ILLUSTRATIONS
8-1. GENERAL. The parts lists and illustrations in Section IX are intended to enable the user to procure the parts
necessary to accomplish repairs to the Strobex Blade Tracker Model 135M-9, manufactured by the Chadwick-Helmuth
Company, Monrovia, California.
8-2. SYSTEM.
a) Those garden variety" parts which should be universally available are listed by Chadwick-Helmuth part number,
and a complete generic description, which should allow procurement from a variety of sources. In these cases, electrical
equivalents are generally available from a number of manufacturers. This is true of resistors, capacitors, diodes,
transistors, etc. However, especially in the case of diodes and transistors, it is important that care be taken to assure that
the replacement part is a true electrical equivalent.
b) Unique parts made by or for Chadwick-Helmuth Co. especially for the Strobex Model 135M-9, are listed by
Chadwick-Helmuth part numbers and a description which is, however, inadequate to reproduce the parts. Such parts
must be procured from the Chadwick-Helmuth Co., except in the few cases where a National Stock Number is shown,
and the part would be available from the Chadwick-Helmuth Co. or from a military depot where that part is stocked.
c) Ordinary screw, nuts, washers, etc., and a number of brackets, etc., which are either very common, or unlikely to
require replacement, are not listed. A written description or sketch will enable the Chadwick-Helmuth Co. to supply such
parts as required.
d) A recommended spare parts list is shown in Section IX. This consists of parts most likely to fail and/or most
likely to be difficult to procure from limited sources, or sources that do not stock sophisticated parts.
e) The part number code is as shown in Table 8-1.
8-1
