So looking at that profile I see a small rise close by that is probably less than my tower. But I have a lot of fir and ceder all around me that are higher than the tower. How well will 5ghz pass through the fir and cedar? 73, Allen ----- Original Message ----- From: Patrick Barthelow To: Puget Sound Data Ring ; esarfl@gmail.com ; Patrick Barthelow ; jeff@gritch.org Sent: Saturday, October 05, 2013 10:38 AM Subject: Re: [HamWAN PSDR] HamWAN portable Hello Guys, I have been following the threads from the eaves here, with interest, because I do/have done this intervisibility/path loss kind of stuff a lot. I recently discovered a very powerful program that can assist in this pursuit. Check out: http://www.heywhatsthat.com . This program will construct, file and store a skyline horizon from any location on the planet, looking in any direction. And it will identify nearby intervening terrain peaks. It will answer questions such as range, and elevations, intervisibility profile plots, bearings, distances, fresnel zones, path loss, etc.. Make your viewshed maps, and file them, in a library of such, on-line, or send them to your colleagues. . Try it out. Enjoy.. Best, 73, Pat On Sat, Oct 5, 2013 at 9:41 AM, Tom Hayward <esarfl@gmail.com> wrote: On Sat, Oct 5, 2013 at 9:26 AM, Jeff Francis™ <jeff@gritch.org> wrote: > http://plane.gritch.org/plane/tn/2013-09-08%2014.18.42.jpg.html > > If you look in the back of the truck, you can see precisely the same > antenna setup that Tom is using laying on top of the spare tire (next to the > stool). From the park, I was close enough I just propped the antenna up and > did it that way. No need for the tripod (and the strange looks from other > park-goers). From that photo, I can tell you that it won't work. You're aimed at the sky. The beamwidth of these dishes is very narrow and they must be aimed precisely in both azimuth and elevation. Here's my algorithm for aiming: - First, I calculate the bearing from my current location to a HamWAN site (your APRS client should be able to do this for you with the HamWAN* objects). - Then I sight that bearing with my compass. - With the Poynting on the tripod mast, I sight down the feedhorn of the Poynting and line it up with the same landmark I spotted with the compass, being sure to keep the feedhorn level in the elevation axis. - At this point the signal LEDs on the modem have usually registered something (I'm connected) and I can pan and tilt slightly in each directly to maximize signal. This works really well for me because I have a sighting compass accurate to 1 degree and I know how to use it. Another technique is to plot the path on Google Earth and look for landmarks along the path. I've done this and sighted "between the two water towers." This technique requires more patience and panning. This is microwave. It's a lot harder to get a signal than VHF, but it's really satisfying when you do (and faster than 1200 baud!). Tom KD7LXL _______________________________________________ PSDR mailing list PSDR@hamwan.org http://mail.hamwan.org/mailman/listinfo/psdr_hamwan.org -- Best, Pat Barthelow apolloeme@gmail.com Google Lunar X prize Team, SYNERGY MOON wwww.synergymoon.com pat.barthelow@synergymoon.com ------------------------------------------------------------------------------ _______________________________________________ PSDR mailing list PSDR@hamwan.org http://mail.hamwan.org/mailman/listinfo/psdr_hamwan.org