Hi Dale. I'm afraid I can't help you at all with your problem, but your post reminded me of something I haven't really thought about for some time. One of my earliest astronomy projects was the construction of a radio telescope, 'way back in high school. Since I'm not ashamed of my age, I'll divulge the year: 1971. (Everyone's supposed to say, "Why Kim, I had no idea you were that old. You look SO young!) Unfortunately, I became distracted by other things and abandoned the project before it got very far. Anyway, at first I had planned to purchase a surplus military parabolic dish to use for an antenna, but it was too costly. I finally determined to build a Yagi array, but not before I realized that a cylindrical parabaloid would have also been very easy to build and with very little skill or exotic materials required. I don't recall why I settled on the Yagi array, I have simply forgotten too much of the physics involved. And that finally brings me to a question I have for you and others: What would be the advantages/disadvantages of one type of antenna over another? I would still rule out the conventional parabolic dish because of the relative complexity of its construction for a basement tinkerer like me. However, the cylindrical parabaloid is still quite easy to construct with some plywood, a simple plot of a parabola on a piece of paper for a pattern, and some hardware fabric or insect screen to cover the surface. Can anyone enlighten me? Remember, you need to explain in terms my few remaining viable brain cells can comprehend. Thanks all. ----- Original Message ----- From: "Dale Hooper" <Dale.Hooper@sdl.usu.edu> To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Sent: Thursday, September 08, 2005 9:19 AM Subject: [Utah-astronomy] Sept. QST source for RT upgrade help | I'm hoping that Gary Liptrot or one of the other amateur radio operators | on the list might be able to help me with this - | | | | I'm trying to determine the best way to upgrade my radio telescope so | that it is fully-steerable. | | | | It's my understanding that the September issue of QST magazine has a | good review of available rotators. But, I've been unable to find a way | to purchase the magazine without joining ARRL. I've tried the Logan | Borders, Hastings, and Wal-Mart as well as amazon.com with no joy. So, | if you could let me know where I could purchase a copy, it would be | greatly appreciated. | | | | Clear skies, | | Dale. | | | | _______________________________________________ | Utah-Astronomy mailing list | Utah-Astronomy@mailman.xmission.com | http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy | Visit the Photo Gallery: http://www.utahastronomy.com | | ______________________________________________________________________ | This e-mail has been scanned by Cut.Net Managed Email Content Service, using Skeptic(tm) technology powered by MessageLabs. For more information on Cut.Nets Content Service, visit http://www.cut.net | ______________________________________________________________________ | |