Surfin': Thrown For a Loop
My favorite television weatherman, Geoff Fox, is a ham (K1GF). He also writes a blog and I have written about him and his blog here before.
I read his interesting blog most days and recently he wrote about finding an antenna in his attic, an National Radio Club (NRC) Altazimuth loop that he used when he was actively chasing broadcast band DX. Reading his blog, I was fascinated with the performance of the antenna. For example, he wrote that while he was working in Charlotte, North Carolina, at 50,000 W WBT, he could turn the antenna to hear KFAB in Omaha, even though both stations were on the same frequency.
My appetite was whetted and I had to find out more about that antenna.
On the Loop Page of JD's Home Page, I found a brief history of the loop antenna including the origins of the NRC Altazimuth loop. Accordingly, the biggest advantage provided by the Altazimuth loop "was allowing the loop to rotate in the vertical as well as horizontal plane. The addition of the alt-azimuth adjustment allows for the elimination of the effects of 'wave tilt' and allows for much deeper nulling of certain stations."
By the way, JD is James Dale, KC0PPA, and his Loop Page is an interesting read and has a long list of links to more loop antenna information scattered around the Internet.
Further surfin' and I discovered that the plans for the original NRC Altazimuth loop may be found in NRC's Antenna Reference Manual, Volume 1, which is available from the NRC Publications Web page.
On his How I Got Started in Radio and Electronics Web page, Mark Connelly, WA1ION, wrote about his radio encounters using the Altazimuth loop at the QTH of the very inventor of the antenna, Gordon Nelson, formerly WA1UXQ.
The Gordon Nelson story continues on page 5 (about two-thirds down the page) of the December 26, 2006 issue of the Shortwave Bulletin, which is available on the Hard-Core-DX.com Web site.
I'm off to the nearby big box home improvement store to buy parts to build the frame for my own loop antenna, so, until next time, keep on surfin'!
Editor's note: Stan Horzepa, WA1LOU, got his start in radio chasing broadcast band DX with a crystal radio kit. To communicate with Stan, send him e-mail or add comments to his blog. By the way, every installment of Surfin' is indexed here, so go look it up.
Stan Horzepa, WA1LOU