This publication serves as notice of intent to procure supplies /service from Ocean Innovations located in La Jolla, CA for the US Department of
Commerce, NOAA, National Marine Fisheries Service for In-stream PIT tag detection requires the installation of RF antennas in a range of river and flow conditions across the watershed of the Columbia River basin. The tag detection electronics must be on-shore for power and data download access, so the connection of the antennas to their controlling transceiver must be accomplished by antenna cable capable of withstanding the stresses of immersion and abrasion. The cable must have the electrical properties determined by the tag antenna frequency (~134kHz) and the power range (<1kW). Additionally, because tag detection is accomplished by antenna field modification rather than simple detection, the entire antenna assembly must operate in a low-noise environment. The cabling between the antenna and the transceiver is an integral part of the antenna assembly, and therefore must conform to the systems rigorous performance constraints.

The required cable must be waterproof and must be able to withstand considerable abrasion. A polyurethane coating, at least 0.06" in thickness, of hardness 85C is required. The exact formulation of the coating material may be proprietary, but must be designed to bond to the base cable, provide waterproofing both as direct water penetration and gaseous permeability that would affect capacitance, and provide abrasion resistance. Standard off the shelf tri-axial cable is not rated for underwater use because the cable construction does not control humidity sufficiently to maintain the cables capacitance rating. This cable is being used as part of an RF antenna, so the capacitance of the cable is critical. Waterproofing usually is concerned w/ resistance separation between conductors, but capacitance is much more critical in this case and is affected by humidity w/in the cable long before there is actual water penetration that impacts resistance.

The antenna cable will be subject to considerable movement; therefore, the components of the cable must be able to resist internal wear and deformation. The co-axial component must be build with nitrogen-gas injected foam polyethylene dielectric, rather than a hollow tube air or traditional foam dielectric. Gas injected foam is capable of much higher velocities compared to traditional chemical foam technology and are comparable to velocities supported by the air gap dielectric designs. Additionally, the gas injection process has a negligible residual effect as compared to the chemical foaming process, improving the overall dissipation factor of the dielectric material. Besides the dissipation factor, chemically-foamed cable typically suffers from center conductor migration. Because the elasticity of the conductor material and the polyethylene is quite different, over time the conductor will creep or cold flow through the polyethylene. Conductor migration is accelerated when the cable is continuously flexed, as it will be in this application. This migration will radically alter the impedance at that point, causing serious VSWR, and dramatically reduce the voltage-breakdown ratings. To avoid this poor mechanical performance the requested cable must utilizes gas-injected high-density polyethylene. In high-density polyethylene foam, cell walls are more uniform and very stiff, resisting center conductor migration and maintaining an consistent impedance tolerance of 50 ± 2 ohms. In additionally, because of the continual flexion, the center conductor construction of the requested cable must be stranded rather than solid.

The electrical properties of the required cable in the frequency and power range of the PIT tag antenna application have been developed by the PIT tag transceiver manufacturer (Digital Angel). All replacement cable must functionally and electronically interchangable with current cables in use.

TECHNICAL SPECIFICATIONS:

Custom 50 ohm Triax cable Construction specifications:
Inner conductor: 7/.0380" Bare Copper - diameter 0.108" nominal.
Dielectric: Foamed Polyethylene - diameter 0.285" nominal
Outer conductor: Bonded Aluminum foil + Tinned Copper Braid
Jacket: Thermoplastic Elastomer - diameter 0.405" nominal.
Outer shield: Tinned Copper Braid
082" wall Black outer Poly-U jacket.
Finished diameter 0.600" nominal.

Electrical Properties:
Capacitance: 23.9 pF/ft
Impedance: 50 Ohms
Velocity: 85%

Attenuation & Average Power (68 degree F)

Authority for sole-source purchase is 41 USC 253 (c) (1) only
one responsible source and no other source will satify agency needs. This
notice of intent is not a request for competitive proposals. However, all
proposals received within 15 days of this publication of this synopsis will
be considered by the government. All responses must be in writing and may be faxed attention Melvin Fondue at (206) 527-7166 or email at
[email protected] . This is a simplified acquisition with an
estimated value of less than $100,000

**** The Westren Regional Acquisition Division, requires that all
contractors doing business with this Acquisition Office be registered
with the Central Contractor Registey (CCR) as of October 1, 2003. After
this date, NO award can be made unless the vendor is registered in CCR.
For additional information and to register in CCR please access the
following web site: http//www.ccr.gov . In order to register with CCR
and be eligible to receive an award from this Acquisition Office, all
offerors must have a Dun & Bradstreet Number (DUN). A DUN number may be
acquried free of charge by contacting Dun & Bradstreet on line at
www.dnb/eupdate of by phone at (800) 333-0505

Bid Protests Not Available