If thermal changes could effect the signal then that would make sense
though I do not recall seeing this for shots as short as we are running
in the higher frequency bands we are using. I always looked at thermal
effects as being a consequence only in the lower (VHF and below) bands.
In my past life as a CATV headend engineer I used to have to deal with
VHF co-channel interference where distant television channels in the VHF
band would ride on top of one another after bouncing off the atmosphere
and down onto my towers in the summer time. I guess it could happen in
the microwave bands also though I never thought it was an issue outside
of VHF. If anyone reads any reference materials on thermal effects of RF
in the 5 Ghz bands and cares to share this would be appreciated by the
group. I believe the effect is known as "tunneling" where a frequency
gets locked between two thermal layers in the atmosphere and "tunnels"
its way across larger distances than would otherwise be normal
propagation. I once read the call letters for a VHF television station
in Los Angeles here in Mt. Vernon, Illinois. Now that is some long
Jeff Mabry wrote:
John - The links are about 60 miles due west of your location.
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of John Scrivner
Sent: Tuesday, August 02, 2005 10:41 AM
To: WISPA General List
Subject: Re: [WISPA] 5.8 GHz PtP - weaker RSLs
We had some Trango weirdness overnight also. We had 3 different links go
down at different times overnight but I do not have any specifics of why
at this time. Where were you seeing this trouble?
Jeff Mabry wrote:
Good Morning, WISPA.
We have witnessed a decrease in five (5) TrangoLink10 5.8 GHz PtPs
Received Signal Levels overnight. These links are deployed in various
geographic locations with an average 12 miles of separation between
tower sites. These links have been active for at least a year (some
longer). A decrease anywhere from 3 to 8 dB has been recorded in the
RSLs with the exception of one (1) link which has had a 7 dB boost in
Weather this morning is about the same as yesterday's weather. Clear
and 72 degrees.
Did anyone else see lower signals this morning? This is a weird issue
to wake up to.
Thank you for your support.
SlingShot Wireless Communications
618.735.2411 x 144
WISPA Wireless List: email@example.com