The Joint Electronics Type Designation System (JETDS) , which was previously known as the Joint Army-Navy Nomenclature System (AN System. JAN) and the Joint Communications-Electronics Nomenclature System , is a method developed by the U.S. War Department during World War II for assigning an unclassified designator to electronic equipment. In 1957, the JETDS was formalized in MIL-STD-196 .
25-820: The SCR-300 , designated AN/VRC-3 under the Joint Electronics Type Designation System , was a portable radio transceiver used by US Signal Corps in World War II . This backpack -mounted unit was the first radio to be nicknamed a " walkie talkie ". In 1940, Motorola (then the Galvin Manufacturing Company) received a contract from the War Department to develop a portable, battery powered voice radio receiver / transmitter for field use by infantry units. The project engineering team consisted of Daniel E. Noble , who conceived of
50-452: A crystal controlled calibration circuit, easy to use tuning/channel selection, tuning lock to prevent accidental frequency changes, and radio relay or retransmission capability using two SCR-300 units and the appropriate cable assemblies. Joint Electronics Type Designation System Computer software and commercial unmodified electronics for which the manufacturer maintains design control are not covered. Electronic material, from
75-422: A (V) signifier. The (V) signifier would be warranted if the item accepted variable configurations of a particular component. For example: A suffix of "(P)" following the type designation number and any modification letters indicates a Unit which is designed to accept "plug-in" modules capable of changing the function, frequency, or other technical characteristics of the unit. The plug-in is not considered part of
100-466: A group or unit type designation that is already linked to a specific system/subsystem/center/central/set may use ( -FT, -IN) if the system/subsystem/center/central/set uses multiple of the group/unit and they are only distinguishable by length. This use is only for new assignments and will not be retroactive For example: Primary batteries (non-rechargeable) are designated using "BA"; Secondary type batteries (rechargeable) are designated using "BB". JETDS
125-404: A military point of view, generally includes those electronic devices employed in data processing, detection and tracking (underwater, sea, land-based, air and space), recognition and identification, communications, aids to navigation, weapons control and evaluation, flight control, and electronics countermeasures. Nomenclature is assigned to: This system is separate from the "M" designation used in
150-646: A relatively large backpack-carried radio rather than a handheld model, the SCR-300 was described in War Department Technical Manual TM-11-242 as "primarily intended as a walkie-talkie for foot combat troops", and so the term " walkie-talkie " first came into use. The final acceptance tests took place at Fort Knox , Kentucky in Spring 1942. The performance of the SCR-300 during those tests demonstrated its capacity to communicate through interference and
175-477: Is denoted by addition of the letter(s) "X", "Y", or "Z". The first such modification would be denoted with an "X", the second with a "Y", the third with a "Z", the fourth with an "XX", etc. If simultaneous modifications are made that improve the equipment as well as affect power input, then both a modification letter (A, B, C, D, etc.) as well as a power requirement modification letter (X, Y, Z, etc.) will be used. For example: A pair of parentheses surrounding where
200-424: Is designed specifically to provide training for one particular unit, then that unit may be specified. If it is a training equipment which can provide practice for various different sets/subsystems/systems etc., then that should be indicated with the appropriate letter indicators. For example: For example: A digit or digits in parentheses following the type designation letters indicates the type of ADPE included in
225-503: Is made up of a two letter group indicator (from the table below), followed by a dash, a group number, followed by a slash, and 1-3 letters specifying the equipment it is "part of" or "used with" (see Table 1). If the group is unique and only "part of" or "used with" one particular equipment, that equipment may be specified. If the group may be used with multiple different items, then it is more appropriate to designate it more generally. For example: The type designation used to specify Units
250-452: Is made up of a unit letter(s) indicator (from the table below), followed by a dash, a unit number, followed by a slash, and 1-3 letters specifying the equipment it is part of or used with (see Table 1). As with Group type designations, if the Unit is unique and is "part of" or "used with" only one particular equipment, that equipment may be specified. If the unit is used with multiple different items,
275-443: Is placed after the type designation number to signify a modification to a specific equipment that still retains at least one-way interchangeability with all previous versions. Modification letters begin with "A" and proceed sequentially. For more information on Interchangeability (see below). Note: the letters "I", "O", "Q", "S", "T", "X", "Y", and "Z" are not to be used as modification letters For example: A suffix "(V)" following
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#1732848559972300-484: Is used in conjunction with an approved Item Name drawn from the H-6 Item Name Directory. For example: The type designation used to specify Systems, Subsystems, Centers, Central, and Sets is made up of a prefix AN/ , three type designation indicator letters, a hyphen, and a type designation number. The AN prefix signifies Army-Navy. The three type designation letters (chosen from the table below) specify where
325-527: The Army Nomenclature System (MIL-STD-1464A). Items are given an Item Level which describes their hierarchy The core of the JETDS system is the combination of a Type Designation with an Item Name to specify a particular item. For example: The type designation is a unique series of letters and numbers which specifies an item. There are three basic forms of type designator used: The Type Designation
350-708: The Normandy invasion and the Italian campaign . It also became "key equipment" that helped deter confusion in the Battle of the Bulge . The British adopted the design of the SCR-300 for their own use from 1947 as the "Wireless Set No. 31". The SCR-300 was an 18-tube battery operated VHF battlefield radio half-duplex transceiver . It used an FM transmitter section and a double superheterodyne receiver. It incorporated an adjustable squelch circuit, an automatic frequency control circuit,
375-626: The United States Coast Guard in 1950, Canada in 1951 and the NSA in 1959 (though the NSA continued to use its own TSEC telecommunications security nomenclature ). In 1957 the U.S. Department of Defense approved a military standard for the nomenclature, MIL-STD-196. The system has been modified over time, with some types (e.g. carrier pigeon -B- ) dropped and others (e.g. computers and cryptographic equipment) added. The latest version, MIL-STD-196G,
400-573: The design using frequency modulation , Henryk Magnuski who was the principal RF engineer , Marion Bond, Lloyd Morris, and Bill Vogel. The SCR-300 operated in the 40.0 to 48.0 MHz frequency range, and was channelized. Along with other mobile FM tank and artillery radios such as the SCR-508 (20.0 to 27.9 MHz) and the SCR-608 (27.0 to 38.9 MHz), the SCR-300 marked the beginning of the transition of combat-net radio from low-HF AM/CW to low- VHF FM. Although
425-474: The equipment designation should include only the indicators which are common or appropriate. If a unit could be described by multiple indicators, the indicator which best describes the unit's primary function should be used. The exception would be if there exists a unit indicator which can describe the unit's multiple functions (see examples below); if such a multi-function describing unit indicator exists, then it should be used. For example: A modification letter
450-619: The equipment is used, what the equipment is, and what its purpose is. The type designation number helps specify the exact item; subsequent items with the same Installation/Type/Purpose are numbered sequentially (i.e. the next item developed after the AN/PRC-34 would be the AN/PRC-35). For example: * Additional info on Installation indicators: ** Additional info on Type of Equipment indicators: The type designation used to specify Groups (assemblies that are used in conjunction with others to function)
475-425: The item. For example: Maintenance equipment that is given a type designation is set up as AN/xxM, where the first two letters after the slash (signifying Installation and Type of equipment) are followed by an M. However, if a maintenance or test Unit or Group is considered a "part of" the item in question, it does not receive the M signifier. For example: A change in the power input voltage, phase, or frequency
500-440: The plug-in's function, then the generic plug-in unit indicator (PL) will be used. For example: Type designators for groups and units like cables, waveguides, cords, etc. may also include a parenthetical "( -FT, -IN)" to designate the specified length. These type designators will not include a specified System/Subsystem/Center/Central/Set type designator after the / but will be given a more generic indicator like /U or /GR. However,
525-633: The rugged quality of the design. Motorola was to produce nearly 50,000 of the SCR-300 units during the course of World War II . The SCR-300 saw action in the Pacific Theater , beginning in New Georgia in August 1943. Colonel Ankenbrandt informed General Meade that "they are exactly what is needed for front line communications in this theater". In his point of view, the main difficulty was keeping them supplied with fresh batteries. The SCR-300 saw heavy use in
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#1732848559972550-412: The type designation number and any modification letters indicates variable components or configurations for said Group/Set/Subsystem/System/Center/Central. A number may follow the parenthetical V to identify a specific configuration. For example: Note: A specific equipment should only be given a (V) signifier if it can be configured with different components, not simply because one of its components has
575-627: The type designation number would be located is used to signify an experimental or developmental model. Type designation number is not required but is useful for clarity. When the developmental model is ready for production, the parentheses are struck off. For example: Electronic type (non-rotating) servo amplifiers are designated "AM"; rotating type servo amplifiers are designated "PU". Plug-in Units which can be described by their function (like receiver, microphone, loudspeaker, etc.) will use those corresponding Unit indicators. If no indicator exists to describe
600-416: The unit itself. For example: A suffix of "(C)" following the type designation number and any modification letters indicates an item which directly contains NSA-controlled cryptographic material. For example: A suffix of "-T n ", where n is a number, indicates equipment (Set, Subsystem, System, Center, or Central) designed to provide training in the operation of a specific set or multiple sets. If it
625-627: Was adopted 16 February 1943 by the Joint Communications Board for all new Army and Navy airborne, radio, and radar equipment. Over time it was extended to cover the Marine Corps and the Navy's ship, submarine, amphibious, and ground electronic equipment. When the Air Force was established as a separate department, it continued the use of the system for electronic equipment. JETDS was adopted by
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