At 20watts, you probably won't need a 15db antenna. :) With lightly licensed, you probably won't need a sector. (less interference).
With GPS timing (ala moto/cell gear) you will have less self-interference. ryan On Mon, Apr 5, 2010 at 10:45 AM, Mike Hammett <wispawirel...@ics-il.net>wrote: > My experience is mostly limited to the WISP market (though I'm not > completely ignorant of other markets). Innovation is always welcome, but > any sector that delivers approximately 90 degrees and 15 dBi performance is > going to be huge. > > > ----- > Mike Hammett > Intelligent Computing Solutions > http://www.ics-il.com > > > > -------------------------------------------------- > From: "Mike" <m...@aweiowa.com> > Sent: Monday, April 05, 2010 12:39 PM > To: "'WISPA General List'" <wireless@wispa.org> > Subject: Re: [WISPA] WISPA TV Whitespaces Meeting with the FCC > > > 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 > > m...@aweiowa.com > > > > > > -----Original Message----- > > From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] 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" <m...@aweiowa.com> > > Sent: Monday, April 05, 2010 11:59 AM > > To: "'WISPA General List'" <wireless@wispa.org> > > 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: wireless@wispa.org > >> > >> 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: wireless@wispa.org > > > > 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: wireless@wispa.org > > > > Subscribe/Unsubscribe: > > http://lists.wispa.org/mailman/listinfo/wireless > > > > Archives: http://lists.wispa.org/pipermail/wireless/ > > > > > > -------------------------------------------------------------------------------- > WISPA Wants You! 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