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(e) Valves constructed with ceramic envelope:
() Valves désigned for operation in ambient temperatores cxceeding 100*À (g) Amplifier Klystrons;
(A) Travelling wave cubes,
29, Thyratron and modulator gas-discharge tubes, as follows:
(a) Those rated for continuous operation with peak current and peak voltage exceeding 100 amperes and 9,000 volts at a pulse repetition Frequency of 200 or more pulses per second;
(8) Hydrogen thyratrons of any rating.
(Note: The following is the definition of thyratron" :
Thyrotron: Any hot cathode gas-filled tube containing 3 or mo
electrodes in which anode current flow is initiated by a control electrode).
30. Electronic components designed for and/or capable of reliable perfomance in relation to their electrical and mechanical characteristics and maintaining their design service lifetime while operating:
(a) Over the whole range of ambient temperatures extending from below
minus 45°C to above plus 100°C; or
(8) At ambient temperatures of 200°C or higher.
21. Materials designed and manufactured for use as absorbers of electro- magnetic waves having frequencies greater than 2 x 10 cycles per second, and less than 3 x 1012 cycles per second.
32. Tantalum electrolytic capacitors not elsewhere specified, as follows: (a) All types designed to operate al temperatures exceeding 83*G (4) Sintered electrolytic capacitora:
(4) Electrolytic capacitors constructed with foila.
13. Electronic computers (except business-type machines, accounting machines
and statistical calculating machines).
14. Equipment specially designed to produce electronic assemblies;
(a) By depositing or printing on insulating panels (including plates aad wafers), or otherwise forming in situ, component parts other than basic wiring: or
(6) By automatically inserting and/or soldering componcats on insubling pancla (including plates and wafers), to which wiring is applied by printing or other means,
35. All electronic control equipment.
36, Magnetometers of the following types:
(a) Fluxgate:
(b) Electron beam sensing;
(c) Paramagnetic;
(d) Nucleonic;
and specialized parts therefor.
37. Magnetic recorders and/or reproducers, other than those designed for voice or music, and specialized recording media and parts and components therefor.
38. Centrifugal testing apparatus or equipment possessing any of the following
characteristica:
(a) Driven by a motor or motors having a total rated horsepower preater
than 400 h.p.j
(6) Capable of carrying a payload of 250 lbs. or more;
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(2) Capable of exerting a centrifugal acceleration of 8 or more "g" on a
payload of 200 lbs or more.
39. Ion microscopes having a resolving power beller than 10 Augstrom units.
4. Oscilloscopes (cathods ray) and specialized parts therefor.
46. Photographic equipment, as follows:
(o) High-speed cinema recording cameras employing:
(1) Film widths 35 mm. or narrower and recording at rates exceeding 3,000 frames per second in the case of equipment using as the Fighting source a steady light flow and 10,000 frames per second in the case of equipment using as the lighting source Bash equip- ment connected to the unwinding system;
(2) Film widths greater than 35 mm. and recording at rates exceeding
64 frames per second.
(6) Other high speed cameras capable of recording at rates in excess of
250,000 frames per second;
(c) Photographic micro-flash equipment capable of giving a dash of 1/100,000 second or shorter duration," at A minimum recurcace frequency of 200 flashes per second.
2 Quartz crystals (worked or unworked) and plates, radio grade only.
41. Measuring and counting equipment, as follows:
(a) Time interval measuring equipment with self-contained reference fre-
quency, having one or both of the following characteristics:
(1) Capable of measuring time intervals of 1/10 second or less with
an error not exceeding 1 micro-second plús 0.001 per cent of the interval measured;
(2) Incorporating counting circuits capable of counting at rates in
excess of 1 megacycle per second.
(0) Counting equipment capable of counting at rates in excess of 1
megacycle per second,
GROUP H.
METALS AND MINERAL MANUFACTURES.
1. Ball and roller bearings and parts therefor.
2 Magnetic metals of all types and of whatever form, eg powder, strip, abcat, castings, and blocks, if possessing one or more of the following characteristics:
(a) Grain oriented sheet or strip of a thickness of 0.2 mm. 10.008 inches)
or less;
(4) Initial permeability 50,000 or over:
(c) Remanence 98 per cent or over of maximum flux for materials having
magnetic permeability:
lich A composition capable of sao coergy product greater than 6 times
100 gausses/dersteds, or containing more than 25 per cent cobalt;
(e) Core loss of wall per kg. (0.45 watts per pound) or less at B13,000 fausses and at 50 cycles per second (136 watts per kg. or 0.62 walts per pound at B-15,000 gausses and at 50 cycles per second) or less for graji oriented sheet and strip of a thickness of 0.3) mm. (0.012 inches) or less.
3. Permanent magnets of all types.
4 Alloy steels containing 50 per cent or more iron and
(a) (1) 10 per cent or more molybdenum (but 5 per cent or mare molybdenum in say alloys containing more than 14 per cent chromium); or
No comments yet.
Private notes are available after approval.