Dahlgren Division, Naval Surface Warfare Center, 17320 Dahlgren Road, Dahlgren, VA 22448-5100

59 -- ANTENNAS, WAVEGUIDES AND RELATED EQUIPMENT SOL N00178-97-Q-0196 DUE 091897 POC Susan E. Johnson 540-653-7858 R. A. Sanford 540-653-7819The E-MAIL: Naval Surface Warfare Center, Dahlgren Division, snjohns@nswc.navy.mil. The Dahlgren Division of the Naval Surface Warfare Center, Dahlgren, VA is seeking sources to supply RF tuner, input 50 OHM impedance, 1-5/8 inch EIA flange connector, output 3/8 inch bowl stud. The purpose of the tuner is to match the output power (20 KW peak, 20KW average of a transmitter with a 50 OHM unbalanced output impedance to an antenna system which utilizes a 35 foot whip. The antenna base used is a steel enclosure that measures 24 inches by 24 inches by 30 inches high with the antenna insulator mounted through the top. One side has an opening 16 inches by 16 inches for the purpose of running the feed line to the antenna. An adjoining side has an opening 16 inches by 18 inches for the purpose of inserting a RF current meter in series with the antenna feed line. This meter is used to take current readings and a shorting bar is used in its place for normal operation. Feed line for the antenna which goes from the antenna base to the output of the tuner is about two feet long. The antenna, base and tuner are positioned on a steel deck which is 120 fet wide by 240 feet long. The antenna tuning system shall meet the following specifications listed below. Systemshall be capable of operating at RF power levels of 20KW average and 20 KW peak, frequency range to 2 to 30 MHZ, maximum VSWR of 1.5:1 or less, sytems power transfer efficiency shall be 85% or greater during operation, shall have a remote control panel with insulated shielded cables long enough to allow it to be located 100 feet from tuner. Cables shall be able to be disconneced from the tuner and the control unit. Four (4) grounding lugs or studs, two (2) on the input side, two (2) on the output side. Lugs size to accept 1/2 inch copper tubing or stud size 3/8 inch, 3/4 inch long. Handles on the sides for moving and carrying, 250 lbs or less shall have four (4) handles and more than 250 lbs shall have six (6) handles. Capacitor and coil (inductor) position indicator meters (0-100%) permanently mounted as part of the control panel, so as to have a full-time reading. Provisions to measure forward and reflected power during transmitter output and to measure VSWR during transmitter output. Equipped with circuits to monitor the base antenna RF currents during operation> Meters used with this circuitry shall have the following scales in amperes 0-1, 0-5-0-10, 0-25, 0-50. Base currents presently are between 2-30 amps, these values are lowered to tenths of amps for testing purposes. Meter shall be permanently mounted as part of the control panel. The tuner shall have two modes of operation, fully automatic and manual (to be controlled from the remote control panel). Provisions for an enable/disable tune function. One tuning is complete, motor drives to coil and capacitor are then disabled. Equipped with frequency synthesizer and necessary accessories required to completely tune te tuner to any given frequency from 2-30 MHZ, prior to putting transmitter output into it. Must have digital frequency selection. Frequency selection increments at least 1 KHZ, transmitter output is 50 ohm unbalanced impedance, 20 KW peak, 20 KW average power. Antenna base utilized 35 feet aluminum section whip. Limit switches are required to stop the rotation of the capacitor and coil just before the ends of their travel. The coil (inductor) shall be varied in steps (positive point contacts) rather than sliding finger contacts, especially if coil is to be a large size. Maximum dimensions of the tuner shall be 36 inches wide by 48 inches long by 30 inches high. The tuner control panel shall fit into a standard 19 inch rack. Total weight of the tuner (excluding control panel) shall not exceed 450 lbs designed to operate on 115VAC on 208VAC 60 cycle power, input RF connector on the tuner shall mate with 1 1-5/8 inch EIA flange connector. Output of the tuner shall be insulated bowl stud 3/8 inch to 3/4 inch size. Tuner shall be completely sealed and capable of holding 5 lbs of pressure. Shall have a value on the exterior for the purpose of applying (dry air or gases) pressure and bleeding it off. The cover shall be designed to allow for ease of removal for the purpose of maintenance. Shall be capable of withstanding VSWR variations of up to 2:1, which could be caused by moving structures in front of the antenna. Designed to withstand exposure to the outside environments, rain, snow, freezing, ice, sun, heat. Outside surfaces shall be painted or of such material to prevent corrosion and deterioration. Temperature range minus 20 degrees F to plus 140 degrees F. Humidity 0% to 100%. Manufacturer shall furnish 20 each of the individual coil (inductor) positive point contacts as spare parts. Tuner's chassis and mounts for all components and wire terminal blocks shall be clearly marked with a symbol and number that can be used as a reference on the schematic diagrams. Calibrations at 500 KHZ increments, in the frequency range from 2-30 MHZ, showing the settings of all controls and meters when tuning the manual mode shall be included in the manuals. VSWR measurements taken at 500 KHZ increments, in the frequency range from 2-30 MHZ shall be included in the manuals. Method for complete calibration of the system shall be described and illustrated in the manuals. Manuals shall have full schematics, circuit description and have theory of operation of the system. Manuals shall have a parts list of non off the shelf components, with description and manufacturer of parts, and a parts list of off the shelf commercial items. Complete testing of the tuner and associated equipment shall be done by the contractor prior to shipment. This testing shall include the following with information in the manuals. VSWR measurements taken at 500KHZ increments from 2-30 MHZ. Calibration of controls and meters for manual tuning of 2-30 MHZ. Calibration of automatic tuning controls. Tests shall be conducted that produce the maximum levels of current, voltage and power that would be produced by a transmitter with an output of 20 KW average and 20 KW peak power. During this test check for arcing, heating and deterioration of thecomponents shall be made. Test the unit will hold 3-5 lbs pressure for 120 hour period. This requirement is a small-business small-purchase set-aside. The item shall be shipped FOB Destination. Vendor will provide cage code, dunns number and tax identification number. Award will be made utilizing Simplified Acquisition Procedures. The Government will not issue a written quote package. All specifications are lised above. Faxes will be accepted. Please fax/mail to the Naval Surface Warfare Center, Dahlgren Division, 17320 Dahlgren Road, Dahlgren, VA 22448. Fax number is 540-653-6812, Attn: Susan E. Johnson, code SD18. Telephone number is 540-653-7858. Closing date is 18 September 1997. Award to be made by 26 September 1997. Delivery is due by 2 January 1998. (0241)

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