On Sat, 29 Aug 2009 08:35:49 -0700 (PDT), KD7HB
wrote:

Exactly right. Back in 1986, I worked for a bank data processing
service in Bellevue, WA. I set up a leased data line between our site
and two banks in Hawaii. The line went to San Francisco then via
satellite to Hawaii. Twice a year the service was stopped for about
1/2 hour while the sun passed through the focus of the satellite dish
in Hawaii. I don't think it affected the SF end of the link. AT&T
always called to warn of the disruption.

If the dish is pointed at a geosynchronous satellite, it should affect
both ends of the link, but at different times of the day. Actually,
for the typical DBS 0.7 meter dish, the outage appears for about 3-5
days and lasts about 5-10 minutes.

I live in a rather dense forest, where finding a "hole" in the tree
canopy for DBS reception is tricky. The best way to locate an antenna
is to check where the sun shines through the trees during the times of
the solar outage. Where there's light on the roof, there's a path to
a specific satellite. I've been posting bi-annual tables to help with
the calcs (when I remember to do so). For example:
http://groups.google.com/group/ba.mountain-folk/msg/69c19369b4a5ffde?dmode=source
It's also a good quality test for dish location. If the dish is
showing tree branch shadows on its face during the solar outage, it
needs to be moved (or the trees trimmed).

Assorted calculators:
http://www.intelsat.com/resources/satellitedata/sundata.asp
http://www.satellite-calculations.com/SUNcalc/SUNcalc.htm
http://www.satellite-calculations.com/Satellite/SUNcalc.htm
http://www.ses-americom.com/americom_2008/siteSections/tools/sunoutage/index.php
The Panamsat derived calculators have a bug in them where it will not
accept dish diameters smaller than 1 meter. For small 0.7 meter DBS
dishes, just use 1 meter and proportionally reduce the outage
duration.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558