Hi, Ben, yours below for reference, and list, The furthest I've made it *successfully* under way is 7 miles. I think I got more like 14 at Little Harbour, to Little Whale, full time, good connectivity. I've made the connection under way at 12 miles, but didn't have a big enough mouth to talk back...
Height is my friend in that the signal expands as it moves out, providing me more coverage. In Caribbean locations (where I expected to, but have yet to go, let alone always) spend most of my time, there will be many situations of homes on hills. It's part of the reason for the downtilt in my spec - the bulk of my reach will be to the basic shore area - but my distance allows greater coverage. My greatest distances under way have been where my tilt matched my heel, more or less, allowing me to paint a clear pattern on the shore. On top of the mast minimizes interference from my other boat stuff; at that, there's a slight difference between port and starboard, fore and aft, performance (in effective communication between a point in those directions) on my unit, due to the small amounts of stuff up there with it. An antenna mounted with anything less than a clear line of sight, whether fiberglass or other (particularly, of course, metal) material, will have a degraded signal. Thus, for most boats, mast-top will be the best, even if not needed for distance... And... I'm rarely connected to an ISP or reseller. Usually it's a private site, so they're usually using the typical <70mw tx - so while height may not be critical, clean signal is... HTH... L8R Skip, enjoying (current scan) 14 open sites, using the one which is much stronger than needed for Vonage, in Lucaya, waiting for a weather window to cross to Saint Simons Island, GA Morgan 461 #2 SV Flying Pig KI4MPC See our galleries at www.justpickone.org/skip/gallery ! Follow us at http://groups.yahoo.com/group/TheFlyingPigLog and/or http://groups.google.com/group/flyingpiglog "And then again, when you sit at the helm of your little ship on a clear night, and gaze at the countless stars overhead, and realize that you are quite alone on a wide, wide sea, it is apt to occur to you that in the general scheme of things you are merely an insignificant speck on the surface of the ocean; and are not nearly so important or as self-sufficient as you thought you were. Which is an exceedingly wholesome thought, and one that may effect a permanent change in your deportment that will be greatly appreciated by your friends."- James S. Pitkin ----- Original Message ----- From: "Ben Okopnik" <[email protected]> To: <[email protected]> Sent: Wednesday, April 15, 2009 11:58 PM Subject: Re: [Liveaboard] Wireless Communication for Cruisers > On Wed, Apr 15, 2009 at 09:11:44PM -0400, Skip Gundlach wrote: >> By popular request, here's the transcript: > > [snip] > > Thank you very much, Skip - great run-down, and much appreciated! > > Just FYI, though: if the furthest WiFi connection you've ever made > is 7 > miles (which is a heck of a distance, given the average!), then you > don't need all that much height. Assuming a 7-mile maximum distance, > here's a chart of required line-of-sight heights for a range of > assumed > access point heights: > > AP height Required receiver height > 0' 38' > 1' 27' > 2' 23' > 3' 20' > 4' 17' > 5' 15' > 10' 9' > > For the rest of it, you can (of course) reverse the two columns; in > other words, if the AP antenna is 38' high, you can have yours at > the > surface of the water, and you'd still see them at 7 miles. :) Given > that > the average ISP/AP owner is *trying* to get the service to you, > they'll > usually have a fairly tall antenna. > > > -- > * Ben Okopnik * Editor-in-Chief, Linux Gazette * _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [email protected] To unsubscribe send an email to [email protected] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
