Date: Sat, 10 Nov 2001 21:39:12 -0700 From: Warner Losh <imp@harmony.village.org> To: "Louis A. Mamakos" <louie@TransSys.COM> Cc: Brian Reichert <reichert@numachi.com>, mobile@FreeBSD.ORG Subject: Re: an and wi ad-hoc talking Message-ID: <200111110439.fAB4dC769351@harmony.village.org> In-Reply-To: Your message of "Sat, 10 Nov 2001 22:43:20 EST." <200111110343.fAB3hKE33446@whizzo.transsys.com> References: <200111110343.fAB3hKE33446@whizzo.transsys.com> <20011110182900.Y327@numachi.com> <200111102300.fAAN0g767233@harmony.village.org> <200111110031.fAB0VS767787@harmony.village.org>
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In message <200111110343.fAB3hKE33446@whizzo.transsys.com> "Louis A. Mamakos" writes: : > At sunrise/sunset we have intersting effects on link quality. We get : > the best signal at night (when it isn't frosting) and during the : > hottest part of the day. : : Are your antennas pointed east and west? The Sun produces measurable : noise, and in fact, is used by some to tune-up receive preamplifiers, : measure antenna gain patterns, etc. If you're pointed near where the : sun rises and sets at the horizon, you're probably seeing this. Well, They are pointed north and south (+- 10 degrees). The reason for morning and evening effects are that they span two rivers, which tend to have fog rising off of them in the morning... Not sure about the evening effects (it is smaller). The evening effect could also be placibo. I'll have to start up data collection again now that we have the new radios installed (the old ones were the pre 802.11b wavelan ISA cards). But it might be something else... : Also, ensure that your parabolic reflectors are painted a flat, : non-glossy color. Note that the optical focus will be coindicident : with the the RF, and your antenna feed might get toasted. If you're : getting sun noise, then you're probably getting sun light, too. Hmmm, I'm not sure that's the problem. They are in good sun light, but I'd expect there would be more of a problem around noon then for our south facing one. And it is pointed flat (well, +- 2 degrees) so given that the sun is at about 60 degrees, iirc, at that time. Warner To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message
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