A04_salient_characteristics.docx

GOES Satellite Antennas (helix or helical type)

Salient Features for GOES Satellite Antennas (helix or helical type)

Shall be a helix (or helical) type antenna enclosed in a UV resistant dome Shall have an impedance of 50 Ohms Shall be optimized for GOES transmissions at 401-403 MHz Shall have a maximum Voltage Standing Wave Ratio less than or equal to 1.5 to 1 between 401MHz and 403 MHz Gain shall be between 5 and 7 dBi Shall have an axial ratio of not more than 6 dB on axis Shall have a 3 dB beamwidth of not less than 90 degrees Shall have a maximum input power of 100 watts Polarization shall be right hand circular capable Impedance shall be 50 ohms Shall have a type N female connector Shall include hardware for mounting the unit to a 2-inch O.D. pipe Shall include hardware provisions for horizontal and vertical elevation adjustments

Size and Weight: Antennas are used in field installations and are often installed next to highway bridges and are prone to damage from vandals. Therefore, shall be a “low-profile” style and no more than 12 inches tall.

Durability: Must exhibit sufficient strength to resist damage from shipping, handling and environmental conditions.

Mounting Hardware: Shall be durable; not easily bent. Must not suffer damage when installed and tightened; Must be reusable due to relocation of antenna

Connecting Hardware: Connection between N-connector and the active elements of the antenna shall be durable; able to withstand multiple attachments and reattachments due to relocation. Users prefer but do not require pigtail-style RF connections due to ease of connection at sites.

Assembly/disassembly: Shall be easily assembled and disassembled for relocation due to possible extreme field conditions.

Compatibility for field use: Antenna must be self-contained, having minimum attached parts, external cables (other than pigtail) and minimum tuning adjustments. USGS Antennas are remotely located and difficult to return to for tuning and repairs. Multiple external parts create potential failure points.

Packaging/Marking

Each antenna (including mounting hardware) shall be individually boxed in one carton. The vendor shall affix the Government supplied bar code labels to each box. Government bar code labels will be supplied following contract award.

Deliveries

The vendor shall deliver 25 antennas within 60 days following contract award. The remaining units shall be delivered in quantities of 25 a month in each successive month following the first delivery.