1971-HKRS30-16-30_Part07 — Page 6

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commercial standard television camera tubes and commercial standard X-ray amplifier tubes).

1.556.

Non-flexible fused fibre optic plates or bundles, baving all the following characteristics-

(4) A fibre pitch (centre-to-centre spacing) of less than $5

microns;

J561.

(6) A light-absorbing medium surrounding each fibre, or inter-

stitially placed between fibres;

1562.

1558.

1559.

1560.

(c) A diameter greater than † Inch (13 min.).

Valves (tubes) electronic, and specialized parts, as follows- (*) (i) Valves rated for continuous-wave operation above 1,000 mega Hertz at the maximum ruted anode dissipation; (0) Valves rated for pulsa operation above 300 mega- Hertz at the maximum rated anode dissipation;

(iii) Valves rated for continuous-wave operation over the frequency range 300 to 1,000 megaHerts and for which, under any conditions of cooling, the product of the maximum rated anode dissipation (expressed in walls) and the square of the maximun frequency (expressed in mega- Hertz) at the maximum rated anode dissipation is greater chan 10%, or where applied to external anode tubes rated only without a radiator, and rated only for free air circula- tion, the product is greater than 5 x 104:

(iv) Valves constructed with ceramic envelopes and rated for operation above 300 mega Herts:

(3) Valves in which the velocity of the electrons is utilized as one of the functional parameters, including but not limited to klystrons, travelling wave tubes and magnetrons, except fixed frequency pulsed magnetrons designed to operate al frequencies in the range 9.3 to 9.5 gigahertz with a maximum peak power output not exceeding 25 kilowatts; (c) Indirectly heated valves of a kind that can be pawed

through a circular hole of 7.2 mm. in diameter,

(d) Valves designed to withstand an acceleration of short

duration (shock) greater than 1,000 g;

(e) Valves designed for operation in ambient temperatures

Exceeding 200°C;

(A) Vacuum tubes specially designed for use as pulse modula- tors for radar or for similar applications, having a peak anode vollage rating of 100 kilovolts or more; or rated for a peak pulse power of 2 megawatts or more.

Hydrogen hyratrons, as follows-

(a) Rated for a peak pulse power output of 2 megawatts or

more: or

(8) Of metal-ceramic construction.

Components and parts used as inductive and capacitive elements in clectronic circuits, designed for or capable of reliable per- formance in relation to their electrical and mechanical charac

1564.

25

teristics and maintaining their design service lifetime while operating ——

(a) Over the whole range of ambient temperatures from below

-45°C, to above + 100°C: or

(6) At ambient temperatures of 200°C. or higher.

Materials specially designed and manufactured for use as absorbers of electromagnetic waves huving frequencies greater than 2 x 108 Hertz and less than 3 x 102 Hertz

Tantalum and niobium electrolytic capacitors, as follows-- (e) All types designed to operate permanently at temperatures

exceeding 85°C;

(b) Sintered electrolytic capacitors, except those having a casing made of epoxy resin or sealed with epoxy resing (e) Electrolytic capacitors constructed with foils.

Electronic components, as follows-

(a) Assemblies and sub-assemblies constituting one or more functional circuits with a component density greater than 75 parts per cubic inch (4.575 paris per cubic cm); (6) Modular insulator panels (including wafers) mounting single or multiple electronic elements and specialized parts therefor;

(c) Integrated circuits, i.e. assemblies and sub-assemblies con- taining one or more functional circuits in which there are both component and interconnections formed by the diffusion or deposition of materials into or on a comman substrate.

GROUP G.

SCIENTIFIC INSTRUMENTS AND APPARATUS, SERVOMECHANISMS AND PHOTOGRAPHIC EQUIPMENT:

Electronic computers and related equipment, as follows- (a) Analogue computers with one or more of the following

characteristics-

1565,

(0) Rated errors less than-

(1) Summers, Inverters and integrators—

(A) Static:

(B) Total at 1 kiloHertz:

(2) Multipliers-

(A) Static:

(B) Total at 1 kiloHertz:

0.02%

0.15%

0.1%

0.25%

(3) Fixed function generators: log x and sino/

cosine-

Static:

() More than 75 operational amplifers;

0.1%

(i) More than four integrator time scales switchable during one programme;