Long Wavelength Array Crossed-Dipole Antenna Ordering Information
The active balun and crossed-dipole antenna may be ordered as described below. A brief technical description and application information is here but for detailed technical information refer to the Long Wavelength Array Front End Electronics memorandum series. Also, this paper describes the details and motivations behind the antenna design in 2012 and provides many details such as wind survivability, construction and installation: A Wide-Band, Active Antenna System for Long Wavelength Radio Astronomy by Brian Hicks at the Naval Research Laboratory (and others).
Front End Electronics
The Front-End Electronics (FEE) is a dual assembly of two identical printed circuit boards (PCB) that acts as an active balun between the antenna dipole elements and the coaxial cable feedline. The FEE has 34 dB of gain and 2.7 dB noise figure; it is powered by 15 Vdc fee through a dual bias-tee and requires approximately 250 mA per dipole (500 mA total). See images at the bottom of this page. The usable frequency range of the FEE is approximately 3 to 200 MHz (but we only test them from 5 to 110 MHz). The FEE contains the electronics one crossed-dipole LWA Antenna but it does not include the hub enclosure (the enclosure is part of the antenna below).
The LWA Antenna is a tied-fork, crossed-dipole consisting of four elements (also called blades and wings) and supporting mast and rods, enclosure for the FEE and all fasteners and hardware. The design frequency range is approximately 5 to 90 MHz. The antenna used at the LWA and shown below but is broken down for shipment (ground screen and cables are not included). The four dipole elements are ready for field assembly using common tools. The steel center mast has nominal 2.375 in (60 mm) outside diameter.
A ground stake to support the center mast is optional but is recommended for most installations. The stake is designed to be driven into the ground and includes a collet and collar assembly to hold and support the antenna mast. The stake is heavy and bulky and some users have used other support methods. Other methods may be necessary depending on the terrain (for example, solid rock and soft soils); however, we do not support any other method at this time.
The shipping configuration depends on the number of antennas ordered. The shipping carton for one set of antenna blades is approximately 4 to 8 x 40 x 64 inches (0.1 x 1.0 x 1.6 m). The center mast and ground stake may be shipped in separate packages. The total shipping weight for a complete antenna including mast and ground stake is approximately 70 lb (32 kg).
Click picture below to view...
* ARO: After Receipt of Order and payment and depending on components lead-time and availability. Note that prices may vary depending on domestic or international shipping.
** Effective 1 January 2022, we will resume shipment of the LWA Antenna to international destinations
International shipments will be made from China directly to all countries except the United States of America. Each antenna is in a package that is 63 x 36 x 8 inches and weighs 70 lb, so antennas will be shipped as freight using international carriers.
Customers should be aware that international freight shipments have become a major problem. The paperwork has become so complicated that a dedicated shipping department is required; we do not have a dedicated shipping department. To make matters worse, every country has different requirements and regulations and these change frequently.
Certain accessories associated with the LWA Antenna, such as the LWAPC, LWAPC-Q and LWA Antenna components, must ship from the USA. Shipments that are able to use the US Postal Service and are valued less than 2500 USD will be shipped to any destination. If the value of a shipment exceeds 2500 USD, that shipment will be broken down into two or more packages.
When inquiring or ordering, please provide your complete shipping address including postal (zip) code and telephone number. Be sure to put meaningful text in the Subject field of your email or your inquiry will be trapped by our spam filters and never delivered.
Prices do not include taxes, duties or tariffs. Charges for customs and brokerage fees may apply to international orders.
Important - Read This Before Ordering or Inquiring