1545.
1546.
1548.
1549.
22
Transistors and related devices (or related semi-conductor amplifying devices such as fieldistors, spacistors and technetrons) and specialized parts therefor, as follows—
(a) Of any type using any semi-conductor material having 4 or more active Juactions within any single block of semi- conditor material;
(b) of any type using a bulk semi-conductor material other
thao germanium or silicon:
(c) Using permanium as the bulk semi-conductor material and
baving any of the following characteristic
(0) An average fT of 40 to 240 megacycles per second and designed to have a maximum collector dissipation greater than 150 milliwatts.
(1) An average FT greater than 240 megacycles per Becond:
(d) Using silicon as the bulk semi-conductor material and
baving any of the following characteristics—
(1) An average FT of up to 500 kilocycles per second and designed to have a maximum collector dissipation greater than 5 wattag
(ii) An average IT from over 500 kilocycles per second to 3 megacycles per second and designed to have a maxi- mum collector dissipation greater than 500 milliwatts;
(ii) Ao average ff from over 3 to 20 megacycles po second and designed to have a maximum collector dissipa- tion greater than 250 milliwatts;
(iv) An average FT greater than 20 megacycles per second:
(v) Mejority carrier devices, including but not limited to field effect transistors and metal oxide semi-conductor transistora:
(vi) A modulus of the current gain in the common emitter configuration of 10 or more for collector currents of 100 microamperes or less.
Dendritic produced forms of any semi-conductor material, or combinations thereaf, suitable for use in diodes or transistors,
Photo cells, as follows-
(a) Photoelectric cells, photo-conductive cells (including photo- transistors and similar cells) with a peak sensitivity at a wavelength longer than 12,000 Angstrom units or shorter than 3,000 Angstrom units;
(5) Photo-transistors (photo-conductive cells including photo- diodes) with a response time constant of I millisecond or less measured at the operating temperature of the cell for which the time constant reaches a minimum.
Photomultiplier tubes as follows--~--~
(a) For which the maximum sensitivity occurs at wavelengths longer than 7,500 Angstrom units or shorter than 3,000 Angstrom units; or
(b) Having an anode pulse rise time of less than 2 nano-
seconds.
1550.
1553.
1555.
1558,
23
Thermal delecting cells, i.. bolometers and thermocoupled detectors, radiant energy types only with a response time con- stant of less than 10 milliseconds measured at the operating temperature of the cell for which the time constant reaches à minimum..
Flash-discharge type X-ray tubes.
Image intensifiers, image converters, and specialized components, including übre optic plates specially designed optically therefor. electronic storage tubes including memory transformers of radar pictures and ruggedized vidipon-type tubes (excluding com- mercial standard television broadcasting camera tubes and commercial standard X-ray amplifier tubes).
Valves (tubes) electronic, and specialized parts as follows-- ()
(0) Valves rated for continuous wave operation over the frequency range 300 -1,000 megacycies per second and for which (at any part of this frequency range and under any condition of cooling) the product of frequency of operation in megacycles per second squared and the power output in watts from the anode(s) of a single envelope at this frequency exceeds 109 when the valve is operating in Class C telegraphy key down conditions or in Class C frequency modulated telephony conditions, or. if performance under these conditions is not known, the product of declared maximum frequency of full ratings in megacycles per second squared and the maximum rated anode dissipation per valve in watis exceeds 5 x 107;
(ii) Valves raled for operation above 1,000 megacycles per second;
(i) Valves rated for pulse operation above 300 mega- cycles per second;
(iv) Valves constructed with ceramic envelopes and rated for operation above 300 megacycles per second; (b) Valves, other than conventional types such as diodes, triades, tetrodes, pentodes, etc., 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 at frequencies in the range from 2.3 to 9.5 gigacycles per second with a maximum peak outpat power not greater than 25 kilowatts;
(c) Indirectly heated valves of a kind that can be passed
through a circular bole of 7.2 millimetres in diameter;
(d) Valves designed to withstand acceleration of short duration
(shock) greater than 1.000 G;
(e) Valves constructed with beryllium oxide ceramic;
(f) Valves designed for operation in ambient temperatures
exceeding 100°C.;
(g) Vacuum tubes specially designed for use as pulse modula- tors for radar or for similar applications, having a peak anode voltage rating of 100 kilovolts or more; or rated for a peak pulse power of 2 megawatts or more.