Today's pop quiz is on antennas! Specifically, does anyone know anything about the odd antenna? Here's a link to a picture: http://members.cox.net/edprice/Antenna.jpg Here's all I can tell you:
1. It's a vertical monopole, about 25 feet high and about 10" diameter. Construction appears to be mostly epoxy fiberglass. 2. Yes, there is some kind of spiral (maybe coax) running part-way down the outside from the top. I doubt that this is a circularly polarized beam, pointed straight up, so the spiral must be some kind of broad-banding effort. 3. The antenna is sitting on a concrete base, 4. There are four heavy coax cables, and probably another control or power cable, coming out of the ground and heading into the base of the antenna. 5. Those three toroidal humps near the base; mechanical re-inforcement or loading coil covers or? 6. That wire near the concrete base is not a counterpoise, it's a roll of concertina razor wire. 7. It seems like a lot of trouble for a receive-only antenna. The coax size makes me think there might be several transmitters connected to the antenna. 8. The site had about a half-dozen of these antennas, with no apparent spatial relationship. 9. The diagonal yellow line is a guy rope for something unrelated. 10. And I can't tell you where it is or who pays the bills or how I got in or out. Sorry about the picture quality, but what can you expect from a nose camera? So, any guesses about frequency range and what this might be doing? Ed Price <mailto:[email protected]> [email protected] NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (FAX) Military & Avionics EMC Is Our Specialty ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please visit http://www.messagelabs.com/email ______________________________________________________________________ - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
