Its a somewhat improved version of the Happy Accident Ground Plane in January 1957 QST
http://p1k.arrl.org/pubs_archive/38955 73 Frank W3LPL ----- Original Message ----- From: "Walter Underwood" <[email protected]> To: "Elecraft QTH.net List" <[email protected]> Sent: Friday, December 7, 2018 11:45:37 PM Subject: Re: [Elecraft] OT: HF discone 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 <[email protected]> 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. >> >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
