Since you are shooting from a hill to a valley, your problem may be due to a temperature inversion. These can form ducts/reflections and cause even microwave signals to "skip". Although a lot of hams love this kind of condition, in your case, it is detrimental to your signal. This in addition to fresnel zone intrusion and WAP11 radio receive sensitivity and output power could all play a role in making this worse than it should be.
This "85 degree" thing also makes it sound like it could be hitting some sort of temperature threshold on your WAP11. Direct sunlight could heat it well beyond 85 degrees, crippling your hardware. There is no real good answer to this problem. All we can do on this list is rattle off things it could be, it will be up to you to use this information and determine what the actual problem is. -----Original Message----- From: Loren Zemenick [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 17, 2003 12:37 PM To: Casey Halverson; Loren Zemenick; Wireless Subject: RE: [BAWUG] Why might a 5 mile link degrade during hot weather? Casey, One antenna is on a 10 foot pole on a hill. The line-of-sight dips 3 degrees to the valley floor below. The second antenna is about 2 feet above and 15 feet from the edge of a sloping composite shingle roof. Aesthetic issues with the homeowner prevented a taller pole. I realize this is a sub-optimum situation but thought if the roof acted as a reflector, the 3 degree reflected RF would miss the 24 dbi antenna. This thinking is irrelevant if the composite shingle scatters the incident RF energy. The puzzling part is that the link degrades from solid to no connection in hot weather. Grasping for theories, I have stretched so far as to postulate that trees in the Fresnel zone have a higher water content when actively photosynthesizing under bright sun and with hot air temperatures. This extra water drops the signal strength on a marginal link into non-operation. Any thoughts you might have are appreciated. Loren Zemenick -----Original Message----- From: Casey Halverson [mailto:[EMAIL PROTECTED] Sent: Tuesday, June 17, 2003 11:21 AM To: Loren Zemenick; Wireless Subject: RE: [BAWUG] Why might a 5 mile link degrade during hot weather? How high are each of your antennas? Is there an altitude difference between the two or are they level? -----Original Message----- From: Loren Zemenick [mailto:[EMAIL PROTECTED] Sent: Monday, June 16, 2003 8:17 AM To: Wireless Subject: [BAWUG] Why might a 5 mile link degrade during hot weather? I have a 5 mile 802.11b link that works fine until air temperatures exceed around 85 F. Over a period of about an hour, the percentage of missed pings grows from zero to 100 percent. Link endpoints are Linksys WAP11 (ver 2.6) configured as a point-to-point bridge with 24 Dbi horzontally polorized antennas. The WAP11's and power supplies have been cooled with no effect. Some trees are in the Frenel zone. The problem happens weekdays and weekends. With WAP11's I don't know of a way to measure signal strength or quality. Does anyone have any suggestions as to what might be causing the outage or how to troubleshoot the problem? Regards, Loren Zemenick -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
