1、MIL-R-L8LI28A 66 = 7779906 0229728 9 m MIL-R-18428A (SHLPS) 2 January 1956 SUPERSEDING MIL-T- 18428(SHIPS) 14 February 1955 MILLTARY SPECIFICATION RADIO SET AN/URN-3, TEST EQUIPMECNT FOR 1. SCOPE 1.1 This specification covers several items of special test equipment which will normally be packaged wi
2、th Radio Set AN/URN-3 to permit a high degree of preventive maintenance and calibration and to insure the greatest possible operational reliability for the basic equipment. 2. APPLICABLE DOCUMENTS 2.1 The following specifications and standards, of the issue in effect on date of invitation for SPECIF
3、ICATIONS bids, form i, part of this specification: MILITARY MIL-C-3098 - Crystal Units, Quartz. MIL-E-15090 - Enamel, Equipment, Light-Gray (Formula No. 111). MIL-E-16400 - Electronic Equipment, Naval Ship and Shore: MIL-T-17113 - Tests; Shock, Vibration, and Inclination(for Electronic MIL-E-17555 -
4、 Electronic Equipment and Associated Maintenmce Parts; General Specification. Equipment) General Specification. Preservation, Packaging, Packing, and Marking of, NAVY DEPARTMENT General Specifications for Inspection of Material. STANDARDS MILITARY MIL-STD-108 - Definitions of and Basic Requirements
5、for Enclosures for Electric and Electronic Equipment. (Copies of specifications, standards, drawings, and publications required by contractors in connection with specific procurement functions should be obtained from the procuring agency or as directed by the contracting officer. ) I 1 I FED. SUP. C
6、LASS 6625 I Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-18428A (SHIPS) 3. REQUIREMENTS 3.1 Reliability. - An extermely high degree of reliability is required for all items furnished. The use of electronic parts and electron tubes, under con
7、servative operating conditions, such as moderate voltages and dissipations, is recommended. 3.2 General. - 5.2.1 This specification covers the requirements for special purpose test equipment which will be installed in Radio Set AN/URN-3 equipment cabinets, as are being furnished the bureau or agency
8、 concerned, and shall meet the requirements of Specification MIL-E-16400, except as otherwise specified herein. 3.2.2 Materials and parts which represent an improvement in the state of the art over materials and parts covered by applicable specifications shall be used to increase reiability, reduce
9、size arid weight, and reduce the effects of heating, Approval of such materials and parts shall be in accordance with Specification MIL-E -16400. Particular attention shall be paid to the acceptable and unacceptable material requirements of Specification MIL-E-16400. 3.2.3 Enclosure. - The equipment
10、 shall have a dripproof degree of enclosure in accordance with Standard MIL-STD-108 when installed in the AN/URN-S equipment cabinets. 3.2.4 Shack requirements, - The equipment shallwithstand shock tests in accordance with class A of Specification MIL-T-17113 when installed in the AN/RN-3 equipment
11、cabinets. The contractor shall repair any and all damages resulting from the tests. in accordance with class 1 of Specification MIL-E-16400. 3.2.6 Temperature, - All major units of the special test equipment shall operate satisfactorily within the limits of this specification in ambient temperatures
12、 of O” to 40” Centigrade (C.) and within twice the tolerance limits in the ambient temperature ranges of minus 28” to 0C. and plus 40” to plus 50C, All units shall remain operable and useful from minus 54” to plus 75”C., although not necessarily within the operational tolerances stated herein, This
13、paragraph applies to test equip- ment installed in the AN/URN-3 equipment cabinets with the AN/URN-3 equipment turned on. 3.2.5 Operating conditions. - Special test equipment shall be capable of continuous operation 3.2.7 Power source, - The equipment shall be capable of operation from a 12O-volt, 6
14、0-cycle source, Major units shail be capable of satisfactory continuous operation with variations of plus or minus 10 percent in line voltage and plus or minus 5 percent in cycles in frequency. Momentary impairment of operation due to a plus or minus 30 percent transient of 1 second duration will be
15、 permissible, but shall not cause failure of parts or prevent resumption of normal operation when the transient has ceased, 3.2.8 Control locking devices. - The design of control locking devices shall be in accordance with Specification MIL-E-16400. 3.2.9 Connectors. - External RF connections shall
16、be made through type “C” or (BNC” con- nectors. Associated external RF cable jacks and plugs shall be furnished and except for front panel connections shall be capable of clamping armor. External video connections shall be made through type connectors, except those used.in the interconnecting harnes
17、s which shall be of the AN” or (BNC” type. Interconnecting harness connectors shall be placed at the rear of the test equip- ment drawers so that the harness may be directly installedin the AN/URN-3 equipment cabinets. 2 - - Provided by IHSNot for ResaleNo reproduction or networking permitted withou
18、t license from IHS-,-,-MIL -R - 18428A (SHIPS) 3.2.10 Tropicalization. - Tropicalization will not be required. 3.2.11 Blown fuse indicators. - Blown fuse indicators shall be provided. 3.3 Detail requirements. - 3.3.1 The equipment shall be designed for use in the AN/URN-3 equipment cabinets, The AN/
19、URN-3 equipment cabinets are serviced from the front only, and special test equipment shall be constructed in a manner mechanically consistent with the design used in the AN/URN-3. The dimensions and location of special test equipment shall be determined by the contractor for the AN/URN-3. 3. 3.2 Sp
20、ecial test equipment assemblies. - The equipment shall consist of the following five main assemblies: Major units Reference Oscilloscope OS - 5 4/URN - 3 Pulse analyzer - Signal Generator TS-89O/URN-3 Generator, Pulse-Sweep SG-12lA/URN-3. 3.3.5 Switch-Tes Adapter SA-420/URN-3. 3.3.7 3.3.3 3. 3.4 3.3
21、.6 Power meter - Pulse Counter TS-891/URN-3 The four major units, reference3.3.3through 3.3.6, are individually packaged (except for shock- mounting and dripproofing, which is accomplished when the assemblies are placed in the AN/Um-3 cabinets) and capable of operating independently. The switch test
22、 adapter which is mounted separately from the AN/URN-3 cabinets shall meet the full packaging requirements. 3.3.2.1 The general appearance of the front panels, the dripproofing treatment and the color shall be compatible with the front panels of the AN/URN-3. External finish coats shall be enamel co
23、nforming to class 2 of Specification MIL-E-15090. 3.3.2.2 Preset testing positions. - The special test equipment shall include two function switches of four positions each, labeled identically such that when set to corresponding positions, the appropriate interconnections among the test equipment un
24、its and the AN/URN-3 will be made to perform all normal testing. These switches shall be located as follows: one on the power meter puise counter unit and one on the oscilloscope. The four positions shall be as shown in tableI. Table I - Preset testing positions. Position : Marking Tests 1 I Operati
25、ng test i RF peak power . : Visual pulse shape : Output pulse count : Transmitter spectrum : : tivity : Reference pulse burst : 2 : Receiver sensi- : : count : Squitter count : Reply count 3 : System delay : Overall delay 4 : General testing : Each unit may be used : : individually 3 Provided by IHS
26、Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-R-18428A (SHIPS) 3.3. 2.2.1 In order to implement the (?Function Switch? method of preset testing, an inter- 3.3.3 Oscilloscope OS-54/URN-3. - The oscilloscope shall use a 5-inch cathode ray tube 3.3.3.1 Bandwidth
27、, - The vertical amplifier between the 3-decibel (db) points shall extend connecting harness will be used for connections among the major test equipment units. and have the following electrical and mechanical characteristics: from 5 cycles to 3 megacycles (mc.). The rise time capability shall be O.
28、15 microsecond. The horizontal amplifier bandwidth shall be sufficient to efficiently handle the sweep speeds specified in 3.3. 3.7 and the external sawtooth sweep specified in 3.3. 5. 4.2 and 3.3. 5.4. 3. 3.3. 3.2 Vertical linearity. - The vertical amplifier output Hnearity shall be within 10 perce
29、nt for a deflection up to plus or minus 2.5 inches as measured about the center of the screen, 3.3. 3.3 Deflection snsitivity. - The vertical deflection sensitivity shall be at least O. 1 volt peak- to peak per inch. The horizontal deflection sensitivity shall be at least 5. O volts peak-to-peak per
30、 inch. 3.3.3.4 Trigger sensitivity. - The sweep shall be capable of being triggered externally by a O, 5 volt peak sine wave or by a O. 5 volt peak pulse as short as O. 5 microsecond and of either polarity. 3.3.3.5 Sweep lag. - The maximum slope of the sweep voltage shall occur on the linear portion
31、 of the sweep. When the sweep circuits are triggered by pulses of either polarity and of O. 5 volt or more in amplitude having rise times of O. 02 microsecond or less between 10 and 90 per- cent amplitude points, the delay between the 50 percent point on the triggering pulse and the point of interse
32、ction of the extrapolated linear portion of the sweep voltage and its zero amplitude level shall not exceed O. 15 microsecond. 3.3.3.6 Input impedance. - The vertical amplifier input impedance at those terminals.not included in the interconnecting harness shall be not less than 1 megohm shunted by a
33、 maximum of 40 micromicrofarads bpf), The vertical signal input terminal of the interconnecting harness connector shall have an input impedance of not less than 1 megohm shunted by a maximum of 100 pt O. 5 db and an input bpedance of not less than 10 megohms shunted by not more than 30 micromicrofar
34、ads. The attenuation figures of both probes shall remain constant within plus or minus O. 5 db over the bandwidth specified in 3.3.3.1. Both probes shall be terminated in BNC connectors and an adapter from the.BNC connector to an alligator clip shall be provided. O. 5 db and an input impedance 3.3.3
35、.7 Sweep speed. - The sweep speed shall be continuously variable from O. 4 to 4,000 micro- seconds per inch and shall be calibrated in terms of total sweep time across the face of the oscillo- scope reticule to an accuracy of plus or minus 10 percent. 4 I Provided by IHSNot for ResaleNo reproduction
36、 or networking permitted without license from IHS-,-,-MIL-R-Lq2A bb W 9777706 0127732 O = MIL-R-18428A (SHIPS) 3.3.3.8 Sweep linearity. - The linearity of the sweep shall be such that if 10 vertical markers are displayed on the face of the tube, the spacing between each of those markers as measured
37、about the center of the screen shall vary not more than 10 percent. 3.3.3.9 Brightness and focus. - When the intensity control is set to its maximum the effective accelerating voltage and beam current shall be such as to produce satisfactory brightness and focus at a writing speed of O. 4 inches per
38、 microsecond at a sweep recurrence frequency of 30 sweeps per second. 3.3.3.9.1 The focus shall be equal to that of the best commercial oscilloscope using the same tube. The range of all focus controls shall be such that they can be adjusted to either side of the optimum setting for all settings of
39、the intensity control. 3.3. 3.10 Sweep jitter. - When triggered by consecutive pulses having rise times of O. 1 microsecond or less, the sweep jitter (defined as the maximum change in the delay time between the triggering pulse and the initiation of the sweep) shall not exceed O. 02 microsecond. 3.3
40、.3.11 Hum level. - With the oscilloscope vertical amplifier set for a sensitivity of O. 1 volt peak-to-peak per inch, and with the input terminals capped but not shorted, the total deformation of the base line due to internal hum shall not exceed O. 030 inch. This specification shall hold for the fr
41、ont panel vertical input terminals, the interconnecting harness input terminals and shall also apply when either probe is plugged in and the probe terminals shorted. 3.3.3.11.1 With the oscilloscope horizontal amplifier set for a sensitivity of 5 volts peak per inch and with the input terminals capp
42、ed but not shorted, the total horizontal deformation of the oscilloscope beam due to internal hum shall not exceed O. 015 inch. This specification shall hold for the front panel horizontal input terminal and the interconnecting harness horizontal input terminals. 3.3.3.12 Light shield. - A removable
43、 light shield shall be provided, finished in a dark nonrefle.ctive surface appropriate for the purpose. The extended gage shall be lined with rubber, or an equivalent substitute. A separate removable bracket capable of 360 degree rotation shall support an adjustable metal reflecting surface to facil
44、itate viewing the oscilloscope at angles up to 90 degrees from the face of the tube. 3.3. 3.13 Calibrating voltage. - A calibrating voltage shall be provided. It shall be possible to read voltages from O. 1 to 100 volts peak-to-peak with an accuracy of plus or minus 4 percent. Three ranges shall be
45、provided of 1. O, 10. O, and 100. Ovolts full scale and a calibrated vernier shall be furnished. 3.3.3.14 Sweep calibration markers. - Sweep markers shall be provided at 1. O and 10. O microsecond intervals. The marker pulses shall be approximately triangular in shape with a width of not more than O
46、. 2 microsecond at the half voltage points and rise and decay times of not more than O. 1 microsecond, These markers shall be calibrated against an internal crystal sthdard. Furthermore, it shall be possible to superimpose these markers on incoming signals to the vertical amplifier. The jitter betwe
47、en the markers and the sweep shall not exceed O. 2 micro- second. The crystal shall be in accordance with Specification MIL-C-3098 and the frequency of the crystal standard shall be accurate to within O. 005 percent, 3.3.3.15 Function switch. - A four position function switch shall be provided label
48、ed in the manner specified in 3.3.2.2. in the first three positions preset vertical amplifier gain, external trigger, and sweep conditions shall exist. These conditions shall be set by means of internal screwdriver adjustments, soldered jumper wires, or a combination of both, independently of the co
49、rresponding front panel controls. In the fourth position, all front panel controls shall be active and preset conditions shall not exist. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MfL-R-18428A (SHIPS) 3.3.3.15.1 In position three” of the function switch, the average value of the incoming horizontal input signals shall appear at the center of the oscilloscope face plus or minus l/Z inch and shall remain there for a
