1、 M IL-R-2 267 8 (WEN I NOVEMBER 1960 MILITARY SPECIFICATION RECEIVER- TRANSMITTER, RADIO RT-542(*)/ASQ 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 two-way radio communicati
2、on with properly equipped surface stations and other aircraft by means of amplitude modulated radio telephony. When installed with the necessary associated equipment the radio set shall provide: (l) Communications by means of AM radio telephony (A3). (2) Reception of special-type signais consistent
3、with the performance requirements outlined herein. (3) Automatic direction finding when installed with certain equipment. (4) Automatic relay wherein reception of signais on one equipment will cause transmission on another as outlined herein. 1. 2 Associated Equipment - The equipment shaii operate w
4、ith the following (l) Antenna AT-l4A/A with RG-8/U cable (2) Headset H-l/AR, H-4/AR, H-l73/AR or equivalent associated equipment which shaU not be supplied as part of the equipment: (3) Microphone - T-17, NAF-213264-6 or Am-M-C1, carbon type (4) Throttle Switch - NAF-1124-17 (5) Control, Radio Set C
5、-2791/ARC or C-2790/ARC (6) intercommunication Set AN/AIC-14 (7) Junction Box J-17A/ARC-5 (8) Jack Box J-22/ARC-5 (9) Direction Finder Group AN/ARA-48 (lo) Mounting- Plenum MT- 2243/ASQ- 56 or MT-2244/ASQ (U) Amplifier- Power Supply-Receiver AM-2310/ASQ Provided by IHSNot for ResaleNo reproduction o
6、r networking permitted without license from IHS-,-,- - _ MIL-R-22678 58 7q477b 0151470 711 MIL-R- 22678 (WEP) 2. APPLICABLE DOCUMENTS 2.1 General - The following documents of the issue in effect on the date of invitation for bids form a part of this specification to the extent specified herein: SPEC
7、IFICATIONS Military MIL-1-22668 integrated Electronic Centrals AN/ASQ-56, AN/ASA-57 and AN/ASQ-58 STANDARDS Military MIL-STD-704 Electric Power, Aircraft, Characteristics and Utilization of Federal FED STD 695 Availability of Documents - When requesting specifications, standards, drawings, Colors (c
8、ollection of 358 standards colors for paints and other materials) and publications refer to both title and number. Copies of this specification and applicable speci- fications required by contractors in connection with specific procurement functions may be obtained upon application to the Commanding
9、 Officer, Naval Supply Depot, Code CDS, 5801 Tabor Avenue, Philadelphia 20, Pennsylvania 3. REQUIREMENTS major design objectives shall be the prime consideration. In so doing, parts and materials requirements shaii conform to Specification MIL-1-22668. 2.2 3.1 Parts and Materials - In the selection
10、of parts and materials, fulfillment of 3.2 Design and Construction - 3.2.1 General - The equipment shall conform with all the applicable requirements of Specification m-8 for design, construction and workmanship except in the paragraphs as modified below: Operational Stability -The equipment shall o
11、perate with optimum performance for 200 hours continuously or intermittently without necessity for readjustment of any controls which are non-accessible during flight. Total Operating Life - The equipment shall have a minimum toial operating life of 5000 hours with reasonable servicing and replaceme
12、nt of parts. Parts requiring replace- ment within this interval and the life of such parts shall be specified by the manufacturer. Cables and Connectors - Connectors used for input wiring or interconnection of removable subassemblies shall be type DA manufactured by the Cannon Electric Company or an
13、 approved equivalent. External connectors shall be Amphenol Type 126-10572 or an approved equivalent, The wires and terminals of this connector shall be potted with a sealing compound which is capable of withstanding temperatures to 125OC. 3.2.4.1 3.2.4.2 3.2.5.1 2 Provided by IHSNot for ResaleNo re
14、production or networking permitted without license from IHS-,-,-MIL-R-22678 58 7779706 OLSL47L 7 I MIL-R-22678(WEP) 25 lb/hr of ambient room air 3.2.ll 3.2.12 Standard Conditions - Cooling Air Maximum Altitude - The maximum altitude under service conditions for the equipment shall be 75,000 feet. th
15、e minimum cooling air flow rates that are required for air inlet temperature varying from 0F to 140F in a 168F environment. The cooling air weight flow as a function of the Radio Receiver- Transmitter pressure drop is specified in the following equation: W = l. O9 (6 A P) O. 667) W = Cooling air flo
16、w rate (ib/min) 3.2.12.1 Minimum External Cooling Requirements - The curve of Figure 1 specifies *lo% lb/min 6A P 2 Corrected total pressure (inches H2O) Q = Density correction P/P r P r = Standard density (O. 0765 lb/ft3) 3.2.14 Input Power Requirements - The equipment shall meet all applicable req
17、uire- ments of MIL-STD-704 and shail give specified performance from the following power sources with characteristics as defined in MIL-STD-704, where applicable, having limits as specified therein, The power required shall not exceed the specified amounts. (i) A. C. Power (Three Phase), Category tt
18、Btt Phase 1 150 va Phase 2 12 va Phase 3 12 va (2) 130 V DC Operating Voltage Limits Reduced Performance Voltage Limits ll5 to 123 and 137 to 145 volts 123 to 137 volts Power, Maximum Operating Limits 48 watts (3) 430 V DC Operating Voltage Limits . 404 to 453 volts Reduced Performance Voltage Limit
19、s 382 to 404 and 453 to 464 volts Power, Maximum Operating Limits 136 watts 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I J W c rn c 2 E a O 20 40 60 80 IO0 IZO 140 COOLING AIR TEMPERATURE OF Figure 1 4 Provided by IHSNot for ResaleNo reproduct
20、ion or networking permitted without license from IHS-,-,-MIL-R-22678 58 m 7797906 0151473 2 m - (4) D. C. Power, Category “B“ Power, Mdmum Operating Limits Power, Maximum during Channel 50 watts 200 watts Change 3.3 Performance Requirements - The performance of the equipment shall be as set forth be
21、low. Unless otherwise specified, these requirements apply under standard conditions to both main and guard channel operation. Reduced performance and service requirements shall apply when specifically outlined. Equipment performance under serviee conditions shall consist of a duty cycle wherein the
22、equipment is operated on a continuous cycle of 10 minutes reception and 5 minutes transmission. At minimum operating temperature the equipment need not meet the requirements under service conditions until it has operated fifteen minutes. Frequency Channels - By means of control box selection, it sha
23、ll be possible to select any frequency in the range of 225. O to 399.9 mc in O. 1 mc increments, These main channel frequencies shall correspond with the arithmetic series 225.00, 225.10, 225.20, 225.30 -399.90 mc. Additionally, it shall be possible to select a fixed tuned guard channel in the range
24、 of 238. O mc to 248. O mc. Unless otherwise specified, the equipment shall be supplied with the guard frequency set for 243. O mc. 3.3.1 3.3.2 Sensitivity - The sensitivity of the receiver shall be such that when an r-f input of 5 microvolts (open-circuit) modulated 30% at 1000 cps is applied the a
25、udio output power shall be at least 50 milliwatts with a signai plus noise-to-noise ratio (modulated to unmodulated) of 10 db or greater. When the main receiver is tuned to frequencies within 5 mc of the guard channel frequency, the main receiver and guard receiver shall meet the sensitivity require
26、ment with 8 microvolts input. Under service conditions the sensitivity shall not be worse than 20 microvolts at any frequency. Under special service conditions of 22 volts dc and 102 volts ac power, the signal plus noise-to-noise ratio shail be at least 10 db for 10,000-microvolt signal modulated 30
27、% at 1000 cps. 3.3.2.1 Degraded or Unuseable Channels Due to Internai interference - Certain main receiver channel frequencies may be degraded or unuseable due to internally generated inter- ference from the guard channel oscillator. When the equipment is supplied with the guard frequency set for 24
28、3. O mc, the main receiver sensitivity measurements shall be made with an input of 20 microvolts at frequencies of 241.1, 241.2 and 275.6 mc. Two unuseable channels, 246.6 mc and 253.3 mc, are permitted. 3.3.3 AVC Characteristics - The AVC action shall be such that when a 1000- microvolt signai modu
29、lated at 1000 cps is applied, the audio output power shall be 25 milliwatts (115%) and when the signal input (30% modulated at 1000 cps) is varied from 10 microvolts to 100,000 microvolts, the audio output power shall not vary by more than f 3 db from the audio output obtained with the 1000-microvol
30、t signai, 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. Additionally, the receiver shaU be protected against blocking under conditions of input signals up to one-half volt. The equipment shall
31、 be provided with an internal volume control which shail be adjusted so as to obtain the required output with the 1000-microvolt signal. Blocking shall be defined as a reduction in audio output to a level below 50 milliwatts, 5 Provided by IHSNot for ResaleNo reproduction or networking permitted wit
32、hout license from IHS-,-,-MIL-R-22678(WEP) 3.3.4 Selectivity -The over-all selectivity of the receivers shall fail within the . Attenuation Below Total Bandwidth Resonant Response Guard Receiver Main Receiver 6 db 60 kc min. 60 kc min. limits set forth below for either standard or service conditions
33、, 60 db 400 kc max. 200 kc Max. 3.3.5 Images and Other Spurious Responses -When receiving on any channel the receiver shall attenuate images and other spurious responses to the maximum practicable extent and in any case not less than 60 db relative to the desired signal, except that the guard receiv
34、er shall be permitted three spurious frequencies attenuated less than 60 db but not less than 40 db. shall present an attenuation of not less than 80 db, relative to the response of the desired signal to signals on the frequencies of the intermediate frequency amplifiers. be so minimized that no evi
35、dence of unnecessary oscillation, instability, or excessive regeneration shall occur at maximum r-f gain setting under either standard or service conditions. Intermediate frequency amplifier) shall be provided with an instantaneus noise peak limiter. The noise limiting action shall effectively limit
36、 the audio output voltage of modulating surges or peaks exceeding5a and the fact that the Government may have formulated, furnished or in any way supplied the said drawings, specifications or other data is not to be regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission to manufacture, use or sell any patented invention that may in any way be related hereto, 14 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
