1、MILITAKY SPECIFICAT ION nECEIVER-TRIIluSMITlER, RADIO FtT-736(-)/ASQ-88 AND DECODER, PUISE xY-S31( *)/ASQ-88 This specification has been approved by the Bureau of Naval Weapons, Department of the Navy. 1. SCOPE 1.1 - Scope - The equipment covered by this specification shall provide bearing, distance
2、, and tone identity information to indi- cate the locai5on of a complementaqy surface station with respect to the aircmft. provide information to indicate the link distance with respect to a similarly equipped aircraft. This equipment is the airborne portion of the short-range air-navigation system
3、known as TACAN (tactical air navigation. ) As a discrete auxiliary function, the equipment shall also 1.2 Design Data - No data is required by this specification (other than reports accompanying samples submitted for testing) or by applicable documents, unless specified in the contract or order (See
4、 paragmph 6.7). 2. APPLICABLE DOCUMENTS 2.1 General - The documents listed in 6.7, of the issue in effect on the date of invitation for bids, form a part of this specifi- cation to the extent specified herein: FSC 5826 Provided by IHSNot for ResaleNo reproduction or networking permitted without lice
5、nse from IHS-,-,-MIL-R-UO ( WP) 3 .I Preproduction - This specification mkes provision for preproduction testing. 3.2 Parts and Materials - In the selection of parts and materials, fulfillment of marior desian objectives shall be the mime con- sideratio;. accordance with Specification MIL-1-81036. I
6、n- so doing, parts and materials requirements shali be in 3.3 Design and Construction. 3.3.1 General - This equipment shall conform with all the appli- cable requirements of Specification MIL-1-81036 for design, construction and workmanship, except in the paragraphs as modified below. 3.3.2.1 Operat
7、ioml Stabilitv - The equipment shall operate with satisfactory performance for 200 hours, continuously or intermittently, without the necessity for readjustment of any contmls which are inaccess- ible during flight. 3-3.3.1 Cables and Connectors - Connectors used for interconnection of removable mod
8、dar subassemblies shall be type D manufactured by Cannon Electric Company, or type i43 manufactured by Amphenol Electronics Corpom- tion, or approved equivalents. modules for mating chassis connectors where applicable. R. F. connectors used for interconnecting subassemblies within the r-f module sha
9、ll be Sealectro type 3000, 3003, 3008, and 3012 or approved equivalents-, and G-i464/ r-f connectors on subassemblies within the r-f module shall be Automatic Metal Products type 311-81450 (modified) and Kl?-O232l or approved equivalents. r-f module to the chassis shall be Dage Electric type 3047-1
10、and 9722-1 or approved equivalents. 126-10572, 126-10753 or approved equj.valents, The wire and terminals of the type 126-10753 connector shall be potted with a sealing compound which is capable of withstanding temperatures to +125OC. Printed card connectors my be used in UG-l465/U Internal r-f conn
11、ectors used for connect5ng the External connectors shall be Amphenol Types 3.3.6 Radio Interference Control - The generation of rad50 irrterference by the equipment and the vulnerability of the equipment to radio interference shl.1 be controlled within the limits of Military Specification n1-1-6181
12、and 11L-1-8i036 with the following changes : 3.3.6.1 Conducted Interference (Parer Lead) - Power lead conducted interference shall be controlled within the limits of Specification 141L-I-6181BI except as follows: Level - Frequency Range 0.15 to 0.25 mc 3000 UV/C 0.25 to 20 mc 1000 UV/C ad 1000. cw 2
13、 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-1105 5 W 7799706 0367796 6 W MLL-R-LLO ( WP) 3.3.6.2 Radiated Interference - Radiated interference shall be controlled within the limits of Specification MIL-I-6181B, under these coditions, the t
14、wo pulses in an interrogation pulse pair shall not differ in peak power level by more than 1 db. transmitted power output shall not drop below 55% of the preceding levels when terminated by a load which presents a voltage standing wave ratio of 2.1 at any phase angle. The 8 Provided by IHSNot for Re
15、saleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-L105 58 M 9999906 01b7802 3.4.3.3.2 - Power Output in A/A Mode - With the equipment transmitting at the search interrogation rate, plus transponding with single pulse replies to the interrogations of one compleniontary ai
16、rcraft as specified in 3.4.5.1, the requirements of 3.4.3.3.1 shall apply. When the equipnielrl; is transponding to the interrogations from up to 24 ccmplementary air- craft, in accordance with paragraphs 3.4.1.2 and 3.4.5.2, the average peak pulse power shall be not less than +27 dbw under standard
17、 conditions or +24 dbw der service corditions, into a 50 ohm resistive load. The transmitter shall be capable of recovery to within 2 db of the specified average peak pulse power within 100 microseconds of a previous transmission. 3.4.3.4 Frequency Stabilitx - The center frequency of the trans- mitt
18、ed signal shall be within - + 100 kc of the specified channel frequency. 3.4.3.5 Transmitter Spectrum - In both the search and track con- ditions, 9 of the transmitted energy shall be within a 500 kc band centered on the specified frequency of that channel, and the remaining energy shall decay in an
19、 essentially smooth manner with increasing or decreasing frequency. muted during channeling in themand A/A modes. 3.l4.3.6 Transmitter Muting - The transmitter shall be automatically 3.4.4 Receiver Characteristics - The radio receiver of this equipment shall provide the following perfomnce in the RE
20、C, T/R, or A/A modes, as applicable: 3.4.4.1 Sensitivity - The equipment sensitivity for tone id.entity, bearing, distance and transponding shall be as prescribrd in 3.4.5.1, 3.4.6.1, 3.4.7.2, and 3.4.8.1 respectively. 3.4.4.2 Decoding - In the REC and T/R modes, the sensitivity of the receiver shal
21、l not decrease by more than 3 db when receiving a TACAN pulse pair spaced + 0.5 microsecond from nominal X channd puise coding. Loss of receiver snsitivit,y shall be at least 30 db for TACAN pulse pairs spaced + 4.0 microseconds from nominal X channel puise coding. The foregoing-shall also apply to
22、transponding sensitivity when in the A/A mode, for the transmission of A/A replies synchronous with the received A/A interrogations. applied to the distance measuring circuity without decoding. In the A/A mode, the received signals shall be 3.4.4.2.1 Suppression of Decoding - Decoding shall be suppr
23、essed during the period starting not more than two microseconds after the external suppression pulse described in 3.4.10.3 has reached 15 volts amplitude and lasting throughout the period the external suppression puise remains at or above 15 volts amplitude. Means shall be provided to prevent decodi
24、ng of this equipments awn interrogation transmissions. paranieters of this specification apply ody when there is no suppression of decoding by external equipment. All related performance 9 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-LLO5 58
25、 = 799990b 0169803 T 3.b.b.3 Selectivity - The equipment shall have 50 db or greater rejection to any normal beacon signal or signals on channels other than the ckannel to which the equipment is tuned. both in the presence ar absence of a desired signal. The desired signal shall be considered reject
26、ed if the -performance requirements of this specification are met, with the exception of allowing an additional 1-degree bearing error. In the absence of a desired signal, the undesired signal shall be considered rejected if no distance, bearing, or identity tone information is obtained. This requir
27、ement applies 3.4.b.4 Amplitude Discrimination - In the REC and T/R modes, the equipmnt shall be capable of rejecting the distance and bearing information from the weaker of two beacon signals received on the same channel when the difference in signal strength is 8 db or more. The performance ob- ta
28、ined from the stronger signal shall met the requirements of this speci- fication, except that an additional l-degree bearing error shall be per- mitted when the two signals differ in level by 8 db. The 8 db of differ- ence shall be measured using test signals, each having an equal modulation percent
29、age but not to exceed a total of 4% modulation. In the A/A mode, the ecpipment shall be capable of rejecting A/A interrogations wheni their signal levels are weaker than the strongest A/A interrogation by the amount specified in 3.4.4.5. 3.4.b.S Automatic Gain Control (AGC) - The AGC signal, shall b
30、e generated subseauent to decodlng. In the air-to-ah mode, an adjustable GC circuit shd-1 be provided. -This AGC shall be adjustable from no AGC action to the normal AGO setting which w ill prevent decoding of any A/A Interrogation pulse Walr which has a signal strength 8 db or more lower than that
31、of the strongest A/A interrogation received, provided that the strongest interrogation is not in excess of -30 dbw; this shall incl-ude the case where the equipment is channeled into an A/. interrogation which is operating at a track interrogation rate as lm as 25.pp/s, and this interrogation is the
32、 strongest received. When an abrupt change is made in the A/A interrogation signal strength applied to the m-736/m-531 in the air-to-air mode, the AGC shall reach 9% of its final value in less than 5 seconds. requirements apply only with the normal A/A AGC setting. equipment shali transpond to recei
33、ved, properly coded, A/A interrogations with single reply pulses in accordance withthe following requirements: Unless otherwise specified, all related performance Transponding Characteristics - In the A/A mode this 3.4.5 3.4.5.1 Triggering Level - The eqiiipment shall transpond with the reply effici
34、ency specified in paragraph 3.4.5.2, when A/A interrogations frma similarly equipped aircraft only, are received at a signal level (at the rtr-736 antenna connector) as indicated below: Conditions I Signal Level Standard -Il4 dbw to -30 dbw Semrice -111 dbw to -30 dbw 10 r _- *-e - Provided by IHSNo
35、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-UO ( WP) 3.4.5.2 Reply Efficiency - Under the conditions noted in 3.4.5.1, the average reply efficiency shall be at least 90%. When the equipment is interrogated by as many as 24 shilarly equipped aircraft, in acc
36、ord- ance with 3.4.1.2, assuming a random distrihtion of A/A interrogations, the average tramponding reply efficiency shall be at least 7C$, provided that this equ2pmerrt is locked-on to one of the other aircraft. 3.4.5.3 Transponder Delay - The delay at the T-736/ASQ-88 antenna connector between re
37、ceipt of the second pulse of an A/A inter- rogation pulse pair and the transmission of the corresponding single A/A reply pulse shall be as follws: Interrogation Level System Delaz 6 db above minimum triggering level -2 to -100 dbw 50 9- 4 microseconds -99 dbw to -30 dbw 50 - + 1 microseconds All de
38、lay times shall. be measured between the 5% voltage amplitude points on the leading edges of the respective pulses. the A/A interrogations transmitted by this equipment priority over the transmission of replies to A/A interrogations from similarly equipped aircraft. period from at least 150 microsec
39、onds preceeding to at least 50 micro- seconds following the transmission of the first pulse of an A/A inter- rogation pulse pair by this equipment. 3.4.5.4 Interrogation Priority - Means shall be provided to give The transmission of A/A replies shall be inhibited during the 3.4.5.5 Automatic Overloa
40、d Control (AOC) - An AOC circuit shall be provided to protect the transmitter from damage due to overinterroga- tion. threshold transmitter prf has been reached. adjustable to the point where the requirements- of 3.4.5.2 are met, while holding the transmitter duty cycle within safe limits. This circ
41、uit shall operate to reduce the receiver gain after the The AOC threshold shall be 3.4.5.6 . Random Triggering Rate - In the A/A mode, the equipment shall not transmit nore than 20 A/A reply single pulses per second, as averaged over a one minute period, under the following conditions: (1) The RT-73
42、6/ASQ-68 antenna connector is terminated in a 50 ohm resistive load. NO externa signi. is present. The interrogation generator is disabled. (2) (3) Bearing Measuring Characteristics - In the REC and T/R In the STANDBY (STBY) and A/A modes, means shall be provided to 3.406 modes, this equipment shall
43、 meet the following bearing measuring require- ments. disable the bearing servo. 11 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.4.6.1 Bearing Sensitivity and Accurac - With nominal signal modulation, the bearing sensitivity and accuracy as meas
44、ured with pre- cision test equipment at the output of the fundamental synchro resolver and the synchro differentia transmitter (with a slmvlated zero degree signal applied to the compass input) shall be as follows: STANDARD CONDITIONS Bearing Bearing Accuracx 270 degrees - + 2 degrees All bearings 2
45、 2 degrees All bearings 2 1 degree All bearings 2 2 degrees SEWICE GONDITIONS Bearing Bearing Accuracy 270 degrees - + 2.5 degrees All bearings f 2.5 degrees Ali bearings f 1.5 degrees All bearings f 2.5 degrees Signal Level Not greater than -117 dbw Not greater than -113 dbw -107 dbw to -35 dbw -35
46、 dbw to -30 dbw Signai Level Not greater than -115 dbw Not greater than -li0 dbw -104 dbw to -35 dbw -35 dbw to -30 dbw 3.lr.6.2 Bearing TracMng Rate - The bearing system shall lock-on and track signals having the bearing changing at rates up to 20 degrees per second in either direction for sipal le
47、vels from -107 dbw to -30 dbw under standard conditions and -104 dbw to -30 dhw Fder service con- ditions, except that at ambient temperatures below -30 C, the tracking rate shall be up to 10 degrees per second, After an additional 15 minutes of operation, the bearing system shall lock-on and track
48、signals havjng bearings chang-j.ng at rates up to 20 degrees per second. 3.4.6.3 Bearing Search Time - A complete bearing search cycle shall not exceed 18 seconds with or without a signal applied except that, at ambient temperatures below -30C, a complete bearing search cycle shall not exceed 40 sec
49、onds after an inti how- ever the calibration shall be such that the distance error at zero miles range is in accordance with the following requirements: Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-h?a-8u.05 ( NP) 3.b.7.6.1 Calibration in -A/A Mode - Under standard conditions in the A/A mode the equipment shall be adjusted to read zero miles 2 0.1 mile, as m
