Two On A Big Ocean The Story of the First Circumnavigation
of the Pacific Basin
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RE: lv-ab: wireless internet

From: Jeremy White (no email)
Date: Wed Oct 04 2006 - 15:31:18 EDT

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    I second that approach. We have the WRT-54G up the mast now, using
    power-over-ethernet, and can see quite far. I am using it as I type this
    email.

    It is really the only cost effective approach that I have found.

    -Jeremy White

    -----Original Message-----
    From:
    [mailto:] On Behalf Of Jim
    Richardson
    Sent: Sunday, October 01, 2006 7:33 PM
    To:
    Cc:
    Subject: Re: lv-ab: wireless internet

    On Fri, 2006-09-29 at 11:53 -0400, wrote:
    > ok guys being a total numptie with these matters can i explain my
    > needs and see if you can make some suggestions on what i can buy (i
    > dont wish to get into building anything - unless it is very very
    > simple) and how to configure the bits and pieces - i am an engineer
    > but know little about wireless etc - just assume i have arrived from
    > mars please.
    >
    > Question is for say $100/200 can i extend the range of my laptop WiFi
    > so that i dont have to take it ashore to the wireless hot spot - lets
    > assume i am going to be at anchor about 1/4 to 1/2 a mile away?
    >
    Yes, with several caveats.

    The basic idea is to take a wifi gateway, like a Linksys WRT54-GL, then
    reflash the firmware, put it up the mast. Connect your laptop's *wired*
    ethernet port to the gateway, and use that as your route to wireless
    nirvana. Obviously, this is a little more technical that most folks are
    comfortable with. But if you want directions on how to do this. A great
    place to start is <www.openwrt.org>

    There's not much you can do to the laptop. Even if your wireless card
    has an external antenna connection (most don't) you don't get much with
    a direction antenna in the cabin. Too close to the water. In the
    cockpit, you might get a bit more, but 1/2mile is really optimistic for
    anything other than a parabolic or tuned horn, and those are unwieldy at
    best.

    Remote mounting a gateway high up, maybe with a patch or colin antenna
    will do what you want. But it requires a fair bit of technical knowhow.
    Either yours, or someone who'll do it for beer :) Check out the local
    college campus for wifi nuts, you might be able to hook up with someone
    who'll be able to help there.

    > We are sailing in the BVI's (where there are lots of free WiFi spots
    > as well as a crazy paid for one that charges you by the day not by
    > usage) not in some marina so we will generally be at anchor which i
    > think means a unidirectional antenna
    >
    > If so what do i need to buy - and from where - i am sure i can connect
    > all the bits and bobs with a bit of basic instruction. I need a PCMIA
    > card as the Laptop has built in WiFi.
    >
    > thanks in anticipation
    >
    > David
    >
    > In a message dated 29/09/2006 07:06:22 GMT Daylight Time,
    > writes:
    > On Thu, 2006-09-28 at 22:42 -0400, Ron Rogers wrote:
    > > Except, you need to use heavy coax cable to prevent signal
    > loss over
    > > extended distances. Locating and installing such cable is
    > difficult and the
    > > cable is expensive. That is why several correspondents have
    > mentioned
    > > devices that employ 16' USB cables or remote antennas with
    > co-located amp
    > > which then connect via cable. The latter hardware is
    > expensive.
    >
    >
    > POE, power over ethernet. CAT5E cable has 4 pairs of wires.
    > You use 2
    > pairs for the ethernet traffic to the router, and 2 pairs for
    > a low
    > voltage AC or DC power line (20v is common) and
    > rectify/regulate at the
    > router on the mast. You put the router in a sealed enclosure,
    > and run
    > the single ethernet cable up the mast. (inside preferred of
    > course) and
    > Bob's your mothers brother.
    > You can use a cheap wireless router like an WRTG-54GL for
    > about $50. Add
    > in about $25 for the antenna, and another $50 for enclosure,
    > cable, and
    > sundries, and you're done.
    >
    > If you use POE, bear in mind that the RJ45 connectors are not
    > waterproof, and need some sealing, and that they are only
    > moderately
    > secure. The little tabs break off after a while, and they can
    > be yanked
    > out. So running the cable into the enclosure, into a loop, and
    > then
    > clamped in the position it needs to connect to the router is a
    > good
    > idea.
    >
    > None of this is going to extend your range beyond a mile or
    > two, if
    > that. Unless you add power, or are willing to trade much more
    > directonality (and thus, lose signal when you move more than a
    > tiny
    > bit.)
    >
    > You're right on the RF cable issue, especially at low power,
    > with high
    > freqs. The line losses would make putting the antenna up on
    > the masthead
    > a losing proposition from the power standpoint. But POE turns
    > that on
    > it's head. More vulnerable in a lightning strike of course,
    > but if
    > lightning strikes my boat, internet connectivity isn't my
    > biggest
    > concern.
    >
    > >
    > > ----- Original Message -----
    > > From: "Jim Richardson" <>
    > > |
    > > | Also, the higher up you put the antenna, the better for
    > this.
    > >
    > >
    > --
    > Jim Richardson <>
    > Erisian Claw
    >
    >
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    >

    -- 
    Jim Richardson <>
    Erisian Claw
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