1、MIL-T-28916 58 = 739990b 0156L85 O W MIL-T - 289 16 (MC) 26 March 1969 MILITARY SPECIFICATION TERMINAL, TELEGRAPH-TELEPHONE : TH-81/GCC 1. SCOPE 1.1 This specification covers requirements for one type of transportable telegraph-telephone multiplex terminal. 2 . APPLICABLE DOCUMENTS 2.1 The following
2、 documents of the issue in effect on date of invitation for bids or request for proposal, form a part of the specification to the extent specified herein. SPEC1 FICAT ION S MILITARY MIL-T-152 - Treatment, Moisture and Fungus-Resistant, of Communications, Electronic and Associated Electrical Equipmen
3、t. Marking for Identification of Electrical, Electronic and Mechanical Equipment. Shore, General Specification. and Associated Repair Parts, Preparation for Delivery of. Identification Plates and Markings, Requirements for. and Ground Electronic Equipment. MIL-T-7 O 4 - Treatment and Painting of Mat
4、eriel, MIL-P-15024 - Plates, Identification-Information and MIL-E-16400 - Electronic Equipment, Naval Ship and MIL-E-17555 - Electronic and Electrical Equipment MIL-E-21981 - Electronics Type Designations, MIL-R-22732 - Reliability Requirements for Shipboard STANDARDS MILITARY MIL-STD-129 - Marking
5、for Shipment and Storage. MIL-STD-188 - Military Communication System Technical Standards. FSC 5805 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-29Lb 58 9999906 OL5hL8b 2 a MIL-T-28916 (MC) MIL-STD-810 - Environmental Test Methods . MIL-STD-
6、826 - Electromagnetic Interference Test Requirements and Test Methods. (Copies of specifications and standards required by suppliers in connection with specific procurement functions should be obtained from the.procuring activity or as directed by the contracting officer.) 3 . REQUIREMENTS 3.1 Gener
7、al. The transportable Terminal, Telegraph- Telephone,TH-81/GCC,shall be a frequency division carrier terminal designed to operate over a 4-wire radio circuit or cable. It shall provide a telephone order wire, four telegraph channels and four telephone or data channels. Each telegraph channel shall o
8、perate over a 2-wire, voice frequency (vf) loop to a Terminal, Telegraph-Telephone, TH-85/GCC, and teleprinter. Telegraph channels shall also be compatible with Telegraph Terminals, TH-5/TG and TH-22/TG. Definitions for abbreviations not defined herein may be obtained from MIL-STD-188. 3.1.1 Tvise o
9、f function of-equipment. The terminal shall constitute a lightweight, high performance, tactical, transistorized frequency division multiplexer in the frequency range of 0.3 to 19.7 kilohertz (kHz) . Withzn this frequency range the equipment shall provide the following: (a) 2.1 kHz including a 1,600
10、 hertz (Hz) signaling source. (b) Four frequency shift, 7.0 unit code 75 baud One duplex order wire with a bandwidth of 0.3 to teleprinter channels in the audio frequency range operating half or full duplex. In half-duplex operation, the nominal transmit and receive loop frequencies are 1,232.5 Hz (
11、mark) and 1,317.5 Hz (space) with a nominal center frequency of 1,275.0 Hz. In full duplex operation, nominal receive loop frequencies are 2,682.5 Hz (mark), 2,767.5 Hz (space) with a nominal center frequency of 2,725.0 Hz. Four duplex voice message channels utilizing the lower sidebands of a single
12、 sideband suppressed carrier system employing harmonics of a crystal oscillator as the carrier frequencies, as specified herein. (c) 2 . _- Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-28916 (MC) 3.1-2 Mount. While the terminal does require
13、a mount, MT.-397O/VCC, it is not to be considered as a part of the Terminal, Telegraph-Telephone, TH-81/GCC, 3.2 First article. Prior to submission of any complete production units for acceptance, the contractor shall furnish first articles for testing under the direction and supervision of the cogn
14、izant Government inspector to determine conformance to this specification. First article is defined as a production sample which will be identical to the production items which the contractor will sub- sequently produce in fulfillment of the contract. Unless otherwise specified, a quantity of five f
15、irst articles shall be furnished (see 6.2) . Approval of the first articles by the activity concerned shall not relieve the contractor of the responsibility to supply equipment conforming to this specification, Examination and testing shall be as specified herein. production units from the first art
16、icles shall be subject to the approval of the contracting officer, subjected to first article tests may be included in the final shipment as part of the total quantity to be supplied under the contract, provided they have been completely refurbished. Any changes or deviations of the The items 3.3 Re
17、liability assurance. Reliability shall receive major emphasis during the design, fabrication and con- struction of terminals. This emphasis shall be reflectedin the assembly processes techniques. The first article, production and sample items shall be subjected to the mechanical and electrical tests
18、 specified in Section 4. Mechanical wear shall be such that mechanical or functional performance is not affected. Abrasion of painted surfaces is allowable. Electrical performance of the terminal shall not be degraded. The conkractor is required to demonstrate that the terminal is capable of calcula
19、ted mean time between failure (MTBF) of not less than 15,000 hours. The contractor is required to demonstrate actual MTBF of not less than 500 hours under standard and service conditions. Test level No. 2 of MIL-R-22732 shall be utilized in establishing demonstrated test conditions. and the determin
20、ation of operational 3.4 Desiqn and construction. Design and construction shall be as follows: 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-28916 (MC) 3.4.1 Mechanical parts, Where mechanical parts are employed, whose functions are to rota
21、te, cam or oscillate against other mechanical parts and the best choice of materials includes other than those specified in MIL-E-16400, use of the other materials may take precedence. 3.4.2 Parts and materials. In the selection of parts and materials, the fulfillment of major objectives shall be th
22、e prime consideration. In all cases, general material requirements as to flammability, fungus-resistance and nontoxicity as specified in MIL-T-152 shall be met. 3.4.3 Nonstandard parts. When it has been determined that requirements cannot be met by use of parts and materials specified in MIL-E-16400
23、, the contractor shall immediately inform the contracting officer by submission of detailed data as required by MIL-E-16400, and shall request approval. 3.4.4 Components. Parts and materials approved by specifications listed in MIL-E-16400 shall be given first consideration. 3.4.5 Case material. The
24、 construction of the case and front panels for the terminal shall be made of cast aluminum alloy. Where panels are removable from the basic case and interconnecting cables permanently enter the case, the openings shall be protected with gaskets and packing to assure watertight protection for the equ
25、ipment in transit. The controls and cable connectors shall be splashproof in operation. 3.4.6 Treatment and paintinq. Treatment and painting shall conform to MIL-T-704. Color shall match Marine Corps . green, No. 23 (see 6.3) . 3.4.7 Standard conditions. The following conditions shall be used as the
26、 basis for establishing normal requirements for conducting laboratory and bench test of the equipment. (a) Room ambient temperature range, +20 Centrigrade (C) to +40 C. (b) Altitude, normal ground. (c) Room ambient humidity up to 95 percent relative. 4 Provided by IHSNot for ResaleNo reproduction or
27、 networking permitted without license from IHS-,-,-VIL-T-2873b 58 7797706 0356389 8 MIL-T-28916 (MC) (d) Input voltage, 24 volts, direct current (Vdc) +5 percent . 3.4.8 Service conditions. The equipment shall operate satisfactorily under .any of the following service conditions: Ambient temperature
28、 range, -40 C to +65O C. Altitude, sea level to 10,000 feet. Ambient humidity, range O to 95 percent relative. Vibration (see 4.3) . Shock (see 4.4) . Input voltage 22 to 32 Vdc. Immersion (leakage) (see 4.5) . Salt fog environment (see 4.11) . Blowing sand and duct (see 4.12). Temperature shock (se
29、e 4.8) . High temperature (see 4.6) . LOW temperature (see 4.7). Storaqe conditions. The equipment shall be capable of beinq stored under the following conditions with a subsequent period of operation: (a) Ambient temperature range -62O C to +71 C. (b) Altitude - Sea level to 50,000 feet. 3.4.10 Sta
30、bilitv. 3.4.10.1 Electrical. The equipment shall operate as specified herein for at least 500 hours, either continuously or intermittently, independent of component failure without necessity for readjustment of any controls .other than those located on the front panel. 5 - Provided by IHSNot for Res
31、aleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-28916 (MC) 3.4.10.2 Mechanical. All controls and adjustments shall be designed so that their position of adjustment will not be altered when the equipment is subjected to the specified service conditions. 3.4.11 Interchanq
32、eability. All components and parts shall be physically, functionally, mechanically and electrically interchangeable with any other equipment produced under this specification. 3.4.12 Identification markinq. Subassemblies shall be identified with the manufacturers part numbers, steel stamped, rubber
33、stamped or silk screened on a fixed surface if available, or on a permanent tag affixed in a manner which shall not impair operation of the assembly, and shall not be easily removable: this marking shall be visible when mounted in the assembly. 3.5 Funqus resistance. The equipment shall be rendered
34、fungus proof by the selection of parts and materials which are nonnutrient for fungus. istics shall be as specified in the following paragraph for normal supply voltage of 22 - 32 Vdc. The terminal shall be operative at a minimum of 18 Vdc. 3.6 Electrical characteristics. The electrical character- 3
35、.6.1 Telephone channels. Each terminal set shall provide four telephone message channels. The channels shall be capable of front panel switching from 2-wire to 4-wire service. They shall be equipped with compandors (compressor expanders) delay equalizers and signaling modules. 3.6.1.1 Frequency resp
36、onse. The nominal 3-decibel (dB) points for the band of the telephone channels, less order wire, shall be at 300 and 3,500 Hz. between 1,000 Hz and 325 Hz, the attenuation shall be within the limits of -1 dB and +2 dB with respect to the attenuation at 1,000 Hz. For all frequencies between 1,000 Hz
37、and 3,450 Hz, the attenuation shall be within the limits of +1.5 dB with respect to the attenuation at 1,000 Hz. For all frequencies - 3.6.1.2 Delav distortion. The delay distortion in the frequency band between 600 and 3,200 Hz shall not exceed 175 microseconds, and in the frequency band between 1,
38、000 and 2,500 Hz shall not exceed 100 microseconds. 6 c Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-28916 58 999970b 015bL9L b II . MIL-T-28916 (MC) 3.6.1.3 Levels and insertion loss. At 1,000 Hz, with an input of O dBm (OdBmO), the inserti
39、on loss on a 2-wire loop shall not exceed 3.0 0.5 dB at 1,000 Hz with an input of -4 dBm (O dBmb); the insertion loss on a 4-wire loop shall not exceed 0.0 L0.5 dB. A preset gain control shall allow the 4-wire output level to be set in the range -2 to +8 dBmO . 3.6.1.4 Total harmonic distortion. The
40、 total harmonic distortion within the band between 300 and 3,500 Hz produced by any single frequency test signal shall be at least -38 dBmO. The design objective shall be at least -40 dBmO. 3.6.1.5 Intemodulation distortion. Measured 2-wire to 4-wire, the individual intemodulation products within th
41、e band between 300 and 3,500 Hz produced by any two equal level tones introduced at -3 dBmO in that band shall be no greater than -30 dBmO. 3.6.1.6 Test tone. The external test tone signal used for transmission testing on 4-kHz channels shall have a frequency 1,000 Hz 225 Hz and shall be at a level
42、of O dBmO. 3.6.1.7 Output variation. Measured 4-wire to 4-wire, noncompanded, a radio frequency level change of 10 dB shall produce an output variation of less than 0.5 dB. 3.6.1.8 Terminal impedance. The terminal impedance of the 2-wire, 4-kHz links or trunks shall be 600 ohms 210 percent in the ba
43、nd between 300 and 3,500 Hz and this impedance shall be as close to a pure resistance as prac- ticable in the specified band. In no case shall the phase angle be otside the limit of Oo to +loo. The terminal impedance of all 4-wire, 4-kHz links ur trunks shall be 600 ohms 210 percent in the band betw
44、een 300 and 3,400 Hz and this impedance shall be as close to a pure resistance as practicable in the specified band. In no case shall the phase angle exceed +loo. 3.6.1.9 Far end crosstalk. Maximum crosstalk plus noise with F1A weighting and with an adjacent channel loaded with tactical design objec
45、tives of -50 dBmO in either the 2- Or 4-wire loops. white noise at O dBmO shall not be less than the MIL-STD-188 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-28916 (MC) 3.6.1.10 Noise on trunks. The noise, on either the 2-wire or the 4-wir
46、e loop, measured at the receiving end, when converted to the zero relative transmission level point in 4-kHz trunk circuits, shall not exceed 39 dBa (44 dBrn, C message weighting) per trunk. i 3.6.1.11 Limitinq on trunks. The limiting action of 4-kHz trunk circuits shall be such as to compress test
47、tone power inserted at the zero transmission level reference point as indicated below. - Input power Two-wire limitins action -10 dBm 0.0 dBm 4-15 dBm Compression None 0.4 dB or less 7 dB or more Four-wire limitinq action, compandor in Input power Compression -10 dBmO (-14 dBm) 0.0 dBmO (-4 dBm) +15
48、 dBmO (ill dBm) None 0.4 dB or less 7 dB or more 3.6.1.12 Lonqitudinal balance. The longitudinal balance on either the 2-wire or 4-wire trunk connection shall be 40 dB or more over the frequency range of 300 to 3,500 Hz. 3.6.1.13 Near end crosstalk. The near end crosstalk of a 4-kH2, 4-wire trunk ci
49、rcuit shall be numerically greater than 25 dB in the frequency band transmitted when measured or converted to equal transmission level points, 3.6.1.14 Spurious sianals. Spurious signals other than noise, crosstalk, harmonic distortion and intermodulation products, for which limits are specified, shall not exceed -60 dBmO, with F1A weighting, for any normal operating condition, at any termination. with ringdown signaling which shall empl
