Modification Letter A modification letter 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: • AN/PAS-13A and AN/PAS-13B are modifications of AN/PAS-13. A new AN/PAS-13A can be used in place of an AN/PAS-13 thermal sight; an AN/PAS-13B can be used in place of an AN/PAS-13 or an AN/PAS-13A. • RT-206A is a modification of RT-206. A RT-206A can be used in place of an RT-206.
Specific Configurations of Variables A suffix "(V)" following 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: • AN/PRC-1(V) would be a complete radio communication set (AN/PRC-1) capable of operating in multiple different configurations with variable components. • AN/PRC-1A(V)4 would be the 4th specific configuration of the AN/PRC-1A(V) radio communication set. • OT-1957(V)2/PRC-1(V) would be the 2nd specific configuration of the OT-1957(V) transmitter group required as a component for the AN/PRC-1(V) radio communication set (which can be configured in various ways). 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 a (V) signifier. The (V) signifier would be warranted if the item accepted variable configurations of a particular component. For example: • AN/ARC-190(V) would NOT be appropriate solely because it used the CU-2314
(V)1/ARC-190 HF Antenna Coupler if it could only accept CU-2314-(V)1 and no other antenna coupler • Since, in reality, AN/ARC-190(V) can actually accept CU-2314(V)1/ARC-190 as well as CU-2275(V)1/ARC-190, the (V) signifier is appropriate. It would also be appropriate even if it only accepted CU-2275(V)1/ARC-190 and CU-2275(V)2/ARC-190.
Plug-In (capable) 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 the unit itself. For example: • R-00(P)/PRC-1 would be a radio receiver unit (capable of accepting plug-in modules) that is required as a component for the AN/PRC-1 radio set.
Cryptographic/Classified 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: •
AN/PRC-163B(V)2(P)(C) would be a portable radio receiver/transmitter AN/PRC-163, modification B, configuration 2, that accepts plug-ins and contains NSA-controlled cryptographic material.
Training (Set, Subsystem, System, Center, or Central) 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 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: • AN/PRC-1-T1 would be the first training set for the AN/PRC-1 radio set. • AN/PRC-T3 would be the third training set for several different AN/PRC-
n radio sets. • AN/URC-T1 would be used for the first training set for AN/PRC-
n and AN/VRC-
n radio sets; this designation indicates a training set which can be used for complete radio sets of similar type and purpose but different installation locations (i.e. some are man-portable, some are vehicle-mounted).
Training (Group or Unit) • A "T" is added after the type designation numbers for a Group or Unit if it is designed to provide training but is not considered "part of" other equipment. If it is "part of" other equipment, the T specifier is not used. For example: • RT-10T/PRC would indicate a training receiver/transmitter Unit that is used with radio sets.
Automated Data Processing Equipment (ADPE) A digit or digits in parentheses following the type designation letters indicates the type of ADPE included in the item. For example: • AN/UYK (1, 4, 5) contains a digital processor (1), Input/Output device (4), and tape equipment (5)
Maintenance Equipment 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: • AN/MPM-8 is used to maintain Radar Sets AN/MPG-5, AN/MPS-5, AN/MPS-12, and AN/MPN-9 • AN/URM-20 can be used to maintain Radio Set AN/TRC-7 or AN/ARC-2
Modified Power Requirements A change in the power input voltage, phase, or frequency 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: • AN/TRC-100X is used for a model of AN/TRC-100 which is modified to run on 24v DC instead of the usual 110v AC • AN/TRC-100AX is used for a model of AN/TRC-100A which has modified power input requirements. Alternatively, it may be used if the model AN/TRC-100 underwent simultaneous modifications that improved the model and affected the power input. • AN/TRC-100B(V)2Y would be the second such power modification to the AN/TRC-100B in its 2nd configuration form\
Developmental/Experimental A pair of parentheses surrounding where 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: • AN/ARC-( ) would designate an experimental radio set • AN/AAR-(87) would designate an experimental airborne invisible light or heat radiation detection system. When ready for production, it would become the AN/AAR-87
Servo Amplifiers Electronic type (non-rotating) servo amplifiers are designated "AM"; rotating type servo amplifiers are designated "PU".
Plug-in Units 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 the plug-in's function, then the generic plug-in unit indicator (PL) will be used. For example: • A microphone plug-in would be designated as MW-2/PRC • A plug-in whose function can't be described by an existing unit indicator would be designated as PL-1/ARC
Varying Lengths 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, 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: • A cable assembly which can be used with the AN/GRC-26 would not be designated CC-5/GRC-26 but would be designated CC-5/U or CC-5/GR. • CX-13293/VRC is already linked to VRC, however, it may use the ( -FT, -IN) specifier because VRC configurations may use multiple CX-13293 group/units which are only distinguishable by length (e.g. CX-13293/VRC (6 FT, 0 IN) and CX-13293/VRC (8 FT, 0 IN)
Batteries Primary batteries (non-rechargeable) are designated using "BA"; Secondary type batteries (rechargeable) are designated using "BB". == Miscellaneous ==