Have you ever taken a really good look at an FM broadcast antenna? Most are circularly polarized so they can be received by both horizontal and vertical receive antennas. Even at 90 MHz they aren't that large either. My choice of sector would be something like that, and would be made of aluminum parts, not panels like we are used to using now. I predict circular polarity will be the norm. Why? Because theoretically, a receive antenna of opposite circular sense exhibits infinite loss. My experiments have shown that reality is less, but you CAN expect at least 30 to 40 dB of isolation. The same 6 MHz segment could be reused on the same tower. The phasing harness on the CPE antenna would have to set to either left hand or right hand circular polarization.
Friendly Regards, Mike Mike Gilchrist Disruptive Technologist Advanced Wireless Express P.O. Box 255 Toledo, IA 52342 239.770.6203 [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mike Hammett Sent: Monday, April 05, 2010 12:23 PM To: WISPA General List Subject: Re: [WISPA] WISPA TV Whitespaces Meeting with the FCC Then the problem arises of frequency reuse if we have such low gain antenna all over the place... and the size of a sector antenna for towers. ----- Mike Hammett Intelligent Computing Solutions http://www.ics-il.com -------------------------------------------------- From: "Mike" <[email protected]> Sent: Monday, April 05, 2010 11:59 AM To: "'WISPA General List'" <[email protected]> Subject: Re: [WISPA] WISPA TV Whitespaces Meeting with the FCC > Just for discussion, let's say a TV LPDA has a gain of 8 dBi. It will > cover > the entire VHF TV band, and by superimposing a UHF LPDA on the same mast, > can cover the entire UHF TV band with similar gain figures. > > I'd make this challenge: > > I could TRY to hide a TV band LPDA on my property and beg you to find it. > Even well hidden, you would. Now, give me a few hours to build a narrow > band antenna with similar gain in ANY 6 MHz segment of the same bands, and > let me try to hide it. Do you think I could hide it well enough you > wouldn't find it? I know I can. > > My point is, the antenna which will be needed for any segment of the > whitespace will be much less intrusive than the LPDA (or Yagi) being used > for comparison. > > This is great dialogue. I hope we are faced with the challenge of > deploying > in these bands. > > Mike > > > > > ---------------------------------------------------------------------------- ---- > WISPA Wants You! Join today! > http://signup.wispa.org/ > ---------------------------------------------------------------------------- ---- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > ---------------------------------------------------------------------------- ---- WISPA Wants You! Join today! http://signup.wispa.org/ ---------------------------------------------------------------------------- ---- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
