[Elecraft] OT: HF discone

[Walter Underwood]

The lower element is a cone, but I think the analysis for the discone is pretty different. At least, that’s what I understood from the L. E. Cebik article.

The WWV antennas don’t need to be wideband, because they have one for each frequency.

"The WWV antennas are half-wave vertical antennas that radiate omnidirectional patterns. There are antennas at the station site for each frequency. Each antenna is connected to a single transmitter using a rigid coaxial line, and the site is designed so that no two coaxial lines cross. Each antenna is mounted on a tower that is approximately one half-wavelength tall. The tallest tower, for 2.5 MHz, is about 60 m tall. The shortest tower, for 20 MHz, is about 7.5 m tall. The top half of each antenna is a quarter-wavelength radiating element. The bottom half of each antenna consists of nine quarter-wavelength wires that connect to the center of the tower and slope downwards to the ground at a 45 degree angle. This sloping skirt functions as the lower half of the radiating system and also guys the antenna.”

https://www.nist.gov/pml/time-and-frequency-division/radio-stations/wwv <https://www.nist.gov/pml/time-and-frequency-division/radio-stations/wwv>

wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)

> On Dec 7, 2018, at 3:02 PM, Fred Jensen <k6dgw at foothill.net> wrote:
> 
> I think one or more of the WWV antennas in Ft. Collins are semi-discone designs with the guy cables acting as the skirt.
> 
> 73,
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
> 
> On 12/7/2018 2:43 PM, Ken G Kopp wrote:
>> There is/was an HF discone at a missle silo in Southern AZ that has/had a
>> coax cable available for public use.  Just drive up and connect your mobile
>> rig.  (:-))
>> 
>> There's another for HF use at the FAA aircraft control center in SLC.
>> 
>> 
> 
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