1、MILITARY SPECIFICATION RECEIVER - TRANSMITTERy RADIO RT-793(*)/ASQ This specification has been approved by the Naval Ar Systems Comnand, Department of the Navy. 1 .o SCOPE 1.1 Scope - The equipment covered by this specification shall provide two-way radio communication in AN/ASQ-l9A and AN/ASQ-88A c
2、entrals with properly equipped surface stations and other aircraft by means of amplitude ,modulated radio telephony. When instal led with the necessary associated equipment the radio recei ver-transmi tter shall provi de the fol 1 owing : (1 ) Communications by means of a-m telephony (A3). (2) Recep
3、tion of special-type signals consistent with the performance requirements outlined herein. (3) Automatic direction finding when installed with certain equipment. (4) Automatic relay wherein reception of signals on one equipment will cause transmission on another as outlined herein. 1.2 Associated Eq
4、uipment - The equipment shall operate with the following associated equipment which shall not be supplied as part of the equipment: Antenna AT-i4A/A Headset W-l/AR or H-4/AR Mi crophone T-17 , NAF-213264-6 or AN8-M:Cl carbon type Control , Central C-6684/ASQ Antenna AS-909/ARA-48 Amp1 i fier-Power S
5、upply-Receiver AM-2349/ASO-19 Intercommunications Station L3-460/AIC In tercomnun i cati ons Sta ti on LS-459/AI C Indi cator y Frequency Channel ID-l311/ASQ THIS DOCUMENT CONTADNS /5 PAGES. 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-LY4
6、3 58 777770b 0370733 5 MILLR-81443 (AS) - 2.0 APPLICABLE DOCUMENTS 2.1 General - The documents listed below of the. issue in effect on - the date of invitation of bids, form a part of this specification to the extent specified herein : Applicable Documents Speci fi cations Mi 1 i tary MIL- 1-61 81 I
7、nterference Control Requirements, Aircraft Equipment MIL- 1-1 8309 Integrated Electronic Central MIL-1-81036 Integrated Electronic Central AN/ASQ-l9A AN/ASQ-88A 2.2 Availability of Documents - When requested specifications, standards, drawings and publications refer to-both title and number. Copies
8、of this specification and applicable specifications required by contractors in connection with specific procurement functions may be obtained upon application to the Commanding Officer, Naval Supply Depot, Code 105, 5801 Tabor Avenue, Philadelphia, Pennsylvania 19120. 3.0 REQUIREMENTS 3.1 ance with
9、AN/ASQ-l9A Specification MIL-1-18309. Preproduction - Preproduction test requirements shall be in accord- 3.2 Parts and Materials - In the selection of parts and materials, fulfillment of major design objectives shall be the prime consideration. In so doing parts and materials shall be in accordance
10、 with AN/ASQ-l9A Specification MIL-1-18309. applicable requirements of Specification MIL-1-18309 for design, construction and workmanship, except as otherwise specified herein. shall .be a minimum consistent with gooddesign and shall not exceed 38 pounds. 3.3 Design and Construction - The equipment
11、shall conform with all the 3.3.1 3.3.2 Reliability - The equipment shall operate with Satisfactory 3.3.2.1 ODerational Stabi 1 i ty Total Weight - The total weight of the equipment, excluding cables, performance, continuously or intermittently for a period of at least 200 hours without the necessity
12、 for readjustment of controls which are inaccessible during flight, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-L443 58 H 777770b 0170732 7 W f- - 3.3.2.2 Operating Life - The equipnt shall have total operating Parts life of p hour8 with re
13、asonable servicing and replacement of parts. requiring scheduled replacement shaU be specified by the contractor. shall have a specified mean (operat tested and accepted as outlined in AN 7 ASQ-19A Specification MIL-1-18309. or interconnection of removable strbassemblies Bh8J.l be type DA manQfactur
14、ed by the Cannon Electric Campany or an approved equivalent. shall be Auphenal type 3126-10572 or an 8pgmved equivalent. teimiaals of this connector shaU be potted with a sealing compound which is capable of withstanding temperatures to 325C. by the radio set and the vulnerability of the radio set t
15、o radio interference shall be controlled with- the limits of Specificstion MIL-1-6181 aad MIL-I- 18309 with the foUowing exceptions: 3.3*2.3 Reliability in Mean Time Between Failures (MXW) - The equipment ) the between failures of 200 hours when 3.3.3 Cables snd Connectors - Connectors used for inpu
16、t wiring External connector8 The wires and 3.3.4 interference Control - The generation of radio interference e 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-81q43 58 7977706 0370733 7 W MIL-R-81443 (Ac) 3.3.4.1 3.3.3.2 Antenna Conducted Key
17、up Condition - Spurious output between 200 and Antenna Conducted Key Down Condition - The magnitude of all emitted 500 mc shall not exceed 100 microvolts average and 400 microvolts maximum. signals from 200 to 500 mc, inclusive, on other than the carrier frequency shall be 40 db or more below the ca
18、rrier signal. The maqnitude of all emitted signals below 200 mc shall be 70 db or more below the carrier siqnal. above 500 mc shall be 80 db or more below the carrier signal. 3.3.4.3 test signals shall be at lxquirements as specified herein. Satisfactory performance when mounted rigidly (without vib
19、ration isolators in ple.ce) sheJ.1 be deraon- strated by lack of mechanical failures and satisfactory operation under se-rvice condition limits after completion of the vibration tests. subj cent aPP1 spec 3.3.5.2 Acoustic Noise - No malfunction of the equipment shall occur when cted to a jet engine
20、exhaust noise of 120 db relative to 0.002 dyne per square meter at frequencies between 20 and 10,000 cps. 3.3.6 Primary Input Power Requirements - The equipment shall meet all cable requirements of MIL-1-18309. fied amounts: The power required shall not exceed the (1) AC Power (Three Phase) 115 v, 2
21、70 VA (2) DC Power 28 V 7 Amps (Including Channeling) 3.4 Performance 3.4.1 General - Unless otherwise specified, values set forth to establish the requirements for satisfactory performance apply under standard conditions to both main and guard channel operation. Reduced performance and service requ
22、irements shall apply only where specifically out1 ined. Equipment performance under service conditions shall consist of a duty cycle wherein the equipment is operated on a continuous cycle of 10 minutes reception and 5 minutes transmission. 5 Provided by IHSNot for ResaleNo reproduction or networkin
23、g permitted without license from IHS-,-,-MIL-R-BLY43 58 W 999990b 0170735 2 M MIL-R-81443 3.4.2 Frequency Channels - By means of control box selection, it shall be possible to select any frequency in the range of 225.00 - 399.95 mc in 0.05 mc increments. These main channel frequencies shall correspo
24、nd with the arithmetic series 225.00, 225.05, 225.10, 225.15, ., 399.95 mc. Additionally, it shall be possible to select a fixed- frequency guard channel in the range of 238.00 mc to 248.00 mc. Unless otherwise specified the equipment shall be supplied with the guard frequency set for 243.00 mc. Sen
25、sitivity - The sensitivity of the receiver shall be such that when an rf input of 4 microvolts, 5 microvolts for guard receiver, (open-circuit) modulated 30% at 1000 cps is applied, the audio output power shall be at least.50 milliwatts with a signal plus noise-to-noise ratio (modulated to unmodulat
26、ed) of 10 db or greater. When the main receiver is tuned to frequencies within 55 mc. of the guard channel frequency, the main receiver and guard receiver shall meet the sensitivity requirements with 8 microvolts input. (Under service conditions the sensitivity of the main receiver shall not be wors
27、e than 7 microvolts, except within 55 mc of the guard receiver frequency the sensitivity shall not be worse than 10 microvol ts. Under service conditions the sensi ti vi ty of the guard receiver shall not be worse than 10 microvolts. and 102 volts ac power, the signal plus noise-to-noise ratio shall
28、 be at least 10 db for 1000-microvol t signal modulated 30% at 1000 cps. microvolt signal modulated 30% at 1000 cps is applied, the audio output power shall be 250 milliwatts (+20%, 59 -lo%, and when the signal input (30% modulated at 1000 cps) is varied from 10 microvolts to 100,000 microvolts, the
29、 audio output power shall not vary by more than 53 db from the audio output obtained from the 1000-microvolt signal. When a main frequency within 5 mc of the guard frequency is selected, the foregoing requirement need be met only over the range 20 to 100,000 microvolts. shall be protected against bl
30、ocking under conditions of input signals up to one-half volt. (Blocking shall be defined as a reduction in audio output to a level below 50 milliwatts) The equipment shall be provided with an internal volume control which shall be adjusted so as to obtain the required output with the 1000-microvolt
31、signal, and then locked before performing other receiver tests. 3.4.3 Under special service conditions of 22 volts dc 3.4.4 AVC Characteristics - The AVC action shall be such that when a 1000 Additionally, the receiver 3.4.5 Selectivity - The over-a within the limits set forth below for either 1 sel
32、ectivity of the receivers shall fall standard or service conditions. Attenuation Below Total Bandwidth Resonant Response Guard Receiver Main Receiver 6 db 60 db 47 kc min. 47 kc min. 200 kc max. 85 kc max. 3.4.6 Regeneration - The interstage and over-all regeneration of the receiver shall be so mini
33、mized that no evidence of unnecessary oscillation, instability, or excessive regeneration shall occur. mediate frequency amplifier) shall be provided with an instantaneous noise peak limiter. The noise limiting action shall effectively limit the audio output voltage of modulating surges or peaks exc
34、eeding 50% 515% modulation of the rf signal. Its action shall be rapid enough to prevent loss of intelligibility due to reduction in receiver gain under the influence of continuous rf noises such as are caused by cornutators, ignition systems, etc. When a pulsed signal having a pulse duration of .1
35、microsecond, a pulse repetition frequency of approximately 500 pulses per second, and peak amplitudes up to 0.1 volt is applied on the same frequency as a desired signal modulated 30% at approximately 1000 cps, not more than 50 microvolts.input (desired signal) shall be required to obtain a signal p
36、lus noise- to-noise ratio of 6 db. 3.4.7 Noise Peak Limiter - The detector of the receiver (following the inter- 6 - - _ - -_ ,-_- -. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4 MIL-R-82443 58 777770b O370736 4 /- Y shall under the f ci rcu of
37、de .MIL-R-81443 (Ml 3.4.8 Audio Characteristics - The audio characteristics of the receiver Except where otherwise stated, these requirements apply be as set forth below. both standard and service conditions, and apply to signals detected by either xed frequency or variable frequency receivers and a
38、mplified in the common headset t. 3.4.8.1 Capability - Under standard conditions, the receiver shall be capable ivering an output of at least 250 milliwatts when a signal having any level between 10 and 10,000 microvolts modulated 30% at 1000 cps is applied. With a 1000-microvolt input signal modula
39、ted 30% at 1000 cps, the total harmonic content of the receiver output shall not exceed 10% at the 250 milliwatt level. Under service conditions the output shall not be more than 5 dtj below that obtained under standard conditions. Under the special service conditions wherein the supply voltage is 2
40、2 volts d-c and 102 volts a-c, an output of at least 35: milliwatts shall be obtained when a 10,000-microvolt signal modulated 30% at 1000 cps is applied. 3.4.8.2 Over-all Fidelity - The audio response shall not vary morme than t1 to -3 db from 300 cps to 4000 cps relative to the response at 1000 cp
41、s. Modulation frequencies outside of the 300 to 4000 cps range shall be attenuated the maximum practicable extent without recourse to inclusion in the receiver of large and/or heavy fi 1 ter components . 3.4.8.3 . Auxiliary Circuit - The auxiliary circuit shall deliver only signals detected by the v
42、ariable frequency receiver. When a 1000-microvol t signal modulated 30% at 1000 cps is applied, the output shall be at least 0.25 volt for a 20,000 ohm resistive load, and when the mbdlation frequency is varied from 70 to 7000 cps, the output for any freqyency in the range shall be within 23 db of t
43、he output obtained at 1000 cps. ratio squelch circuit shall be incor orated in both the main channel and guard channel receivers. Under standard conditions the adjustment range of each control shall be such that the squelch threshold can be set to correspond to an output signal plus noise-to-noise r
44、atio between the limits of 3 db and 10 db when the r-f signal input of less than 4.0 microvolts Is modulated 30% at 1000 cycles per second. action so that the receiver audio is either completely off or completely on at all times. Unless specified otherwise the squelch shall be adjusted to open at a
45、6 db signal plus loise-to-noise ratio,.+l db. 3.4.9 Carrier-to-Noise Ratio Squelch Characteristics - A carrier-to-noise Internal squelch thresh0 P d level controls shall be provided in both receivers. The squelch circuit shall have positive Under service conditions with no rf signal input the squelc
46、h - shall not open. RF Power-Output - The transmitter shall be capable of del the following values of radio frequency carrier ene.rgy within the range descr 3.4.10 Standard Conditions NLT 20 watts average(16 watts Service Conditions 7 watt min. Reduced Performance Test 3 watt min. at 102 v a-c rmt/o
47、r 22 v d-c. I veri ng bed bel ow: mi ni mum) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-81443 (AS) 3.4.11 Modulated Characteristics - The transmitter shall meet the following requirements for modulation when operated under both standard .a
48、nd service condi ti ons , 3.4.11.1 Modulation (Radio Telephony A-3) - Under standard conditions the modulator shall be capable of modulating the r-f carrier output of the transmitter not less than 80% when the input voltage at 1000 CDS obtained from the dumv microphone(per Paraqraph 3.5.1.1U.4) is a
49、djusted to 1 volt (open circuit) fop the carbon mlcrphone and to 0.15 volt (open circuit) far the dynamic microphone. Modulation shall be determined from osc the modulated carrier wave and from measurement of maximum and on the oscilloscope. Modulation shall be calculated from the lloscope presentation of minimum vol tage displayed ormula: The modulator of this equipment shall employ clipper or limiter provisions for clipping positive
