It happens to me shooting over a city with very little corn at all. It'll happen anywhere there may be a lack of wind and different layers of air density.
----- Mike Hammett Intelligent Computing Solutions Midwest Internet Exchange The Brothers WISP ----- Original Message ----- From: "Kurt Fankhauser" <lists.wavel...@gmail.com> To: af@afmug.com Sent: Monday, August 28, 2017 9:39:38 AM Subject: Re: [AFMUG] 5Ghz thermal fade w/ Corn would this still be happening if i was shooting over a bare field with no vegetation or is this a corn related/exagerated effect? On Mon, Aug 28, 2017 at 10:14 AM, Cameron Crum < cc...@wispmon.com > wrote: Would be interesting to see a graph related to temperature and humidity vs signal strength to see if there is some ducting, or even temp probes at different elevations during the event Also, how does the corn plant itself behave during the day? Do the leaves lift or sag or stay the same? Corn leaves are pretty wide and smooth. I wonder if they could be acting like a nice smooth reflective surface due to a rise of the leaves? On Mon, Aug 28, 2017 at 7:49 AM, Adam Moffett < dmmoff...@gmail.com > wrote: <blockquote> Ken said he would (where possible) position the antenna so the center of the path was passing over a tree. I guess if the issue was destructive reflections off the corn then the tree attenuates those reflections? ------ Original Message ------ From: "Chuck McCown" < ch...@wbmfg.com > To: af@afmug.com Sent: 8/27/2017 11:27:12 PM Subject: Re: [AFMUG] 5Ghz thermal fade w/ Corn <blockquote> First time I ever heard about this was many years ago from Ken Hohof. Corn and pine trees seem to have a unique effect on RF. From: Kurt Fankhauser Sent: Sunday, August 27, 2017 8:43 PM To: af@afmug.com Subject: [AFMUG] 5Ghz thermal fade w/ Corn I have a customer on a PMP450 SM at 5Ghz link only 2.8 miles out. This SM normally sits at -62 or -65. Every evening for the last 2 months SM will fade to -80 or worse and sometimes even disconnecting for a couple hours then it comes right back. AP is 120 feet height customer CPE height is about 15' height There is alot of corn fields across this link i have in the past seen problems with corn links. I don't know why but shooting across corn is sometimes a problem. Other thing i thought of is the AP is mounted on top of of a very large steel grain bin that probably is heating up during the day maybe it is giving off heat when the sun first goes down we have started to get cool in the evenings here. I am about ready to move customer to a different frequency band he is pissed his Netflix is not working during prime time. Inline image 1Inline image 3 </blockquote> </blockquote>
