Alpha Delta HF SWL-S Sloper Antennas are a very unique and very effective adaptation of existing antenna theory. They operate as quarter wave slopers, which means that the wires are one quarter wavelength long; or multiples of a quarter-wave on each frequency band. Length of the Antenna is 40 ft Long
These SWL Sloper Antennas are designed to cover: Medium Wave (0.5 to 1.6 MHz) and the 120, 90, 60, 49, 41, 31, 25, 21, 19, 16 and 13 meter SWL shortwave bands.
Compared to a standard half wave dipole, the other quarter wave of these antennas, which is necessary for performance and the proper feed point impedance, is made up of the "Down-Lead" wire, which is attached.
With a quarter wave sloper, the center conductor of the coax is attached to the radiating wires and the shield of the coax is attached to the down lead. Standard SO-239 (UHF female) connectors are provided on these antenna for this purpose.
Excellent performance is attained with installations of only 20 to 40 ft. in height. Historically, and by design, quarter wave sloper antennas are known to be excellent DX and long haul antennas. The current lobes, which define the major radiation characteristics of an antenna, are up high at the feed point and are not as subject to attenuation as a vertical antenna, whose current lobe is at ground level.
An side by side comparison between this antenna and a 32 ft. commercial vertical with 18 radials show the DX-SWLs to be as much as 10 dB stronger into Europe and Africa.
Since a sloper has an optimized low-angle radiation pattern for peak DX performance, it will greatly outperform a dipole mounted at the same height. Exceptional for those really distant weak signal DX stations! The difference can be phenomenal.
HF sloper antennas come fully assembled and use stainless steel hardware, UV-protected coils and components, and 12 AWG wire. They are designed to survive severe-weather environments. Insulators and support rope are included.