Well I've finally made it through all the posts in this thread and feel like I can add a few things based on my own research
and trial and error (lots of error!).
The Alpha 500 performs very well and in terms of plug and play as well as value it simply can't be beat. I have used it hoisted at the end of a chain of one passive and one active usb extension cable or with just one passive cable with no detected loss of performance. The one problem we had was when it accidentally got left out in the rain in Buquron PR recently. At first it was no problem but later, the solder connection where the usb connector attaches to the board broke off. I'll re-solder that *and* order a new one as well. Even with a great ship-side system you might like one for shore excursion or as pointed out... charters and delivery work.
I've tried the engenious products and don't like the user interface. Even with plenty of geeky help I found it to be on the clunky side. So far as I know at this time they are using a processor that does not play well with the open source crowd so there is no support for running third party software
such as DD-WRT. It's a shame because the radio gear
in those units really kicks butt. We have discussed here the importance of receiver sensitivity. I believe the engenious is superior to anything else I've played with in this department. The Bullet 2HP is on my watch list and it can run DD-WRT although you will have to pay a $20 fee to brainslayer which is still the biggest bargain of the world. If you are not at least a little geeky you want to someone who is to do your firmware swap. Screw this up and you end up with a “brick” or an unusable, unrecoverable unit.
Currently I'm sending this through what I believe is the ultimate system for us. I am wirelessly hooked to our WRT54GL router which in turn is associated with a distant open network. No second router necessary. No ethernet cable or POE. Currently I'm using a Yagi but that's because I'm at home. The highly directional Yagi we have proved nearly useless on our recent journey from BVI to Nassau
although we did, out of shear desperation, once hook up to a distant station to do quick email
with one person hand aiming the antenna while another person checked email
. A PITA but hey... when you are desperate... So the Yagi stays in our arsenal. I'm building an Omni now and I'll post my findings on that later. One thing I think worth mentioning is that with the Omni antenna the "beam" is often angled upward. So unless you are really reaching for that horizon you might consider *not* going for the sky with it and keep it closer to deck
. Someone mentioned spreaders (we don't have any) but that's not a bad compromise in my view.
In terms of simplicity I like our setup because we use our router in client-bridge mode and run a virtual wifi
network to redistribute the signal in our boat. I first tried this in Culebra
. At first it worked perfectly. We were unable to get a solid hookup to the town's free wifi with just our lap tops but after I set up the router, hooked to an omni that was installed on the davits
(came with the boat we were on) I was able to get a solid hookup. We ran three lap tops off of our virtual network aboard and all was well for the first hour until things really started slowing down. When I checked I found that another half dozen boats in the anchorage had logged onto *our* network! So I went back into the security
settings and set us up with WEP security
to solve that. Selfish? Perhaps but the network was becoming un-usable. I really like the fact that I use no ethernet at all. I access the router wirelessly through our virtual network so the only two connections to the router are a 12 volt power lead and the (very short) antenna coax. Another advantage of the WRT54G/DD-WRT setup is that the antenna leads (2 each) are software switchable. This means I can attach two different antennas to the unit and switch back and forth depending on conditions, without actually unhooking or hooking anything.
So... about power. Wow. All I can say is that with the DD-WRT I can unlock
the power of our router and take advantage of it's full power – a mediocre 251mw. But in practice I find that it's not necessary (or wise) to pump it all the way up. If your antenna can't use all that power you will end up with a distorted signal and defeat your purpose. Think of turning your stereo up too loud for your speakers. This is also unkind to people trying to use adjacent channels. Also heat is an issue... I normally run around 89mw and get great results. This might seem counter intuitive in a culture steeped in SUV-Highrise-Supersise mentality but I'm speaking of my own practical results here and I'll take that over theory any day. Remember... it's a two way street with receiver sensitivity being just as important as transmit power. Be aware that marketing
departments might not be giving you the transmitters true power rating of any given device anyway, but projecting the “power” as a derivative of the actual transmitters power coupled with a high gain antenna. YMMV!
or signal to noise
ratio. There are a ton of devices using the same or close enough frequency to wifi to cause problems with your signal. The microwave oven
in our house was the culprit for a while and cordless phones are also a problem. Just something to be aware of.
About line of sight. It really is not strictly line of site because the radio
waves tend to wrap around objects. Just sayin'.
The general principal of keeping the coax run short is absolutely sound practice.
About wireless security. It isn't.
To get to the next level I've tried studying books
on wifi and even on my specific router but frankly I realize that I'll have to go to the junior college and take beginning network classes
and work my way through. Luckily I have the time if I decide to do it.
Thanks for all the great posts on the topic. Now let's all pray for fast up/down satellite Internet
with a small omni antenna and a cheap
monthly unlimited rate.