Recently we had a tropospheric ducting episode which affected ever 2.4 p2mp customers. There was a layer of warmer air actually trapped by a layer of cooler air. This junction looks like a mirror to radio waves and can be steered or bounced quite a bit off target.
When I built microwave links in S FL that had to be very reliable, we engineered for space diversity. One 22 mile link at 6GHz used pairs of dishes with 30' separation. It would switch many times in a year, and during tropo events, several times in one night. Gulf areas are more apt to see tropo events. Here in the midwest they are uncommon. This may not be the case with your link, but is worth learning about. Here is a nice site for tropo predictions. http://www.dxinfocentre.com/tropo_car.html Mike At 10:33 PM 8/7/2009, you wrote: >So, what causes this crazy loss on all of my 'longer' 5.8 links after >dark/overnight? Temp drop? Contraction? Condensation? Moonbeams? > >More importantly, is there anything I can do about it? Anyone else dealing >with it? > >Links are N-S, E-W and NE-SW, different brands radios, but all in the ISM >5.8 spectrum. Can start as early as 8pm but usually after midnight. Goes >until the suns been up 1 to 3 hours. Doesn't happen every day, but seems to >be predominant in the summer when we get over 90 degrees with 90% humidity >and then the afternoon/evening rain from the buildup. I see it happening to >short links also, just doesn't get bad enough to "drop". > > >Ideas?[image: 2009-08-07_221007.jpg] > > >Ed Spoon >triparish.net / cajun.net >Computer Sales & Services, Inc. >Ph: 985-879-3219 / Fax: 985-876-6789 > >PRIVILEGED AND CONFIDENTIAL COMMUNICATION > >This electronic transmission and any documents attached hereto may contain >confidential and/or legally privileged information. The information is >intended only for use by the recipient named above. If you have received >this electronic message in error please notify the sender and delete the >electronic message. Any disclosure, copying, distribution, or use of the >contents of information received in error or otherwise is strictly >prohibited. > >Content-Type: image/jpeg; name="2009-08-07_221007.jpg" >Content-ID: <ii_122f807387d6193a> >X-Attachment-Id: ii_122f807387d6193a > > > > >-------------------------------------------------------------------------------- >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/
