The solution I described will not use the wifi receiver internal to your
laptop due to the limitations I described in my earlier post. Instead will
use your laptop's Ethernet connection, which runs into a simple POE
interface box. (See the following url for the POE wiring instructions
http://www.nycwireless.net/poe/ ).



The input to this POE box is dc power and the Ethernet connection from your
computer. The DC power comes from the AP or Bridge supplied power adapter.
The output of the POE box is a cat-5 Ethernet cable spanning up to 300 feet
in length. This cable runs to your nema enclosure and now combines the DC
power and Ethernet.



If your access point or bridge is compatible with the IEEE 802.3af standard
one simply plugs the cat-5 cable into the AP or Bridge Ethernet connector.
If you do not have a compatible AP or Bridge one simply splits off the DC
power and wires it directly to the PCB's dc input power terminals.



This solution works equally well irrespective of the use of a desktop (
http://www.fantasia35.com/images/nav-1-03.jpg ) or laptop computer within
your vessel.



I hope this clarifies my wifi implementation strategy.



Regards,

David

"Skip Gundlach" skipgundlach sez use my name at earthlink dot fishcatcher
(net) - with apologies for the spamtrap wrote in message
...
Hi, David, and thanks for the post (left below).

Are you saying that you hoist an antenna which is also a bridge? And that
the cat5 uses 2 sets of the twisted pairs, one for power and the other for
signal?

Where does the power and signal come from in your laptop/computer? In my
case, the wifi is built into the computer. I was hopeful of not having to
buy another card, carrying coals to Newcastle, so to speak...

Thanks.

L8R

Skip

--
Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain
"David Moore" wrote in message
...
Hi,

I went from being able to receive one access point with high packet loss
to
receiving more than 20 solid high signal strength access points.

The problem with most wifi receivers is that their interface to your
computer is either pcmcia or usb. In both cases there is a severe
limitation
to the height of your antenna.

My solution was to use a Netgear wifi bridge. This product has ethernet
out
allowing the device with antenna to be elevated up to 300 feet. In my
application I simply installed the pcb of the bridge into a water proof
nema
enclosure and hoisted it up to within 3 feet of the top of my mast. In a
standard ethernet cat 5 cable there are 8 wires and only 4 are used to
make
a connection. I used the unused set of four to provide DC power to the
bridge. This therefore means that there is only one cable going to the
elevated box.

To my delight, the first time I powered up the elevated bridge I was able
to
receive more than 20 access points.

This solution has worked so well for me that the next time I pull my mast
I
plan to mount the nema enclosed wifi bridge perminately to the top of the
mast.

Hope this helps.
David

Hi, David, and group(s),

The solution I described will not use the wifi receiver internal to your
laptop due to the limitations I described in my earlier post. Instead will
use your laptop's Ethernet connection, which runs into a simple POE
interface box. (See the following url for the POE wiring instructions
http://www.nycwireless.net/poe/ ).

Thanks for the link. Below, you may see why this might not be needed for my
setup.

The input to this POE box is dc power and the Ethernet connection from
your
computer. The DC power comes from the AP or Bridge supplied power adapter.
The output of the POE box is a cat-5 Ethernet cable spanning up to 300
feet
in length. This cable runs to your nema enclosure and now combines the DC
power and Ethernet.



If your access point or bridge is compatible with the IEEE 802.3af
standard
one simply plugs the cat-5 cable into the AP or Bridge Ethernet connector.
If you do not have a compatible AP or Bridge one simply splits off the DC
power and wires it directly to the PCB's dc input power terminals.



This solution works equally well irrespective of the use of a desktop (
http://www.fantasia35.com/images/nav-1-03.jpg ) or laptop computer within
your vessel.



I hope this clarifies my wifi implementation strategy.

Indeed. Are you up and running with it? Do you have an antenna stick
mounted on the mast?

You may not recall, but the F35s were on our short list. I recall seeing
your setup in the website until we actually got aboard one and found that we
were unable to adequately address the stern berth (see the forum archives
for discussion). Your boat looks to be an absolutely marvelous example of
the type.

As much as might be achieved, I'm even, now, considering doing up-the-mast
with a cat5 (or any other 12V) feed to a bridge in a waterproof (NEMA) box,
thence to an external antenna
http://www.keenansystems.com/store/c...1401cfa1d316d4

and

http://www.keenansystems.com/store/c...1401cfa1d316d4
an 8.5 dB gain antenna atop the mast just above the box.

There's some potential for a couple of miles, and the added enhancement of
our ability to use our laptop ashore, communicating with the boat, or, of
course, both the nav and topsides (the one we'd carry ashore, if we had to)
computers on at the same time if we cared to do so.

I'm also looking into fab-corp.com products as potentially having more gain
in the antenna portions. They may also have some bridge solutions, but I
have not yet had a response to my query about their total solution ideas.

However, as attractive as cat5 is for getting signal up the mast, it makes
me tied to the boat as I understand your setup. For that reason, I don't
know that I'd pursue that. *IF* - maybe a big "if" - I can make this work,
I'd be able to see that bridge from anywhere on or even pretty far away from
the boat, with either of the two laptops (one "shoreside use" and other "nav
use" we expect to have aboard. So, aboard could be in communication with
shoreside via IM, for example, or, better (for our circumstances), we could
be in communication with anyone in the world via VOiP. My current carrier,
Vonage, has a "softphone" feature which is in the computer; tying in with a
headset/mike combo makes for better sound than the speaker and built-in
mike. If we had a reliable connection, we could be on the phone anywhere we
had access, something which is *very* attractive to Lydia, who has 4"
Stainless Steel Hawsers for apron strings...

Back to the cat5, though, if you look at the URLs for Keenan, I'm wondering
if what you're saying is that one uses cat5 to get signal to the masthead,
and powering the bridge is a coincidence of the cat5 connection from the
comptuter. Might one power a wireless bridge (which would then see my
laptop sitting on the boat somewhere) and put the signal up the mast to the
antenna at the top? I'd sure rather have the bridge below than in a NEMA
box at the top...

Thanks again for the input (all who have contributed, too!).

L8R

Skip, refitting as fast as I can...

Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain

Skip,
Yes, I remember your earlier search for a cruising sailboat and your
consideration of the Fantasia 35. I am happy to hear that you have selected
and purchased a vessel and indeed are well underway with your refit. It's
too bad you couldn't fit into the aft skippers bunk. I am confident that
with your enthusiasm, you would have been a regular on the Fantasia 35 forum
http://www.fantasia35.com/disc5_toc.htm
My wifi system is fully operational however it is temporally installed. The
Wifi Bridge is installed in a nema enclosure and hoisted to near the top of
the mast. http://www.fantasia35.com/images/wifi-22.jpg A permanent
installation shall be completed the next time I pull the mast. The POE
interface box is mounted below and near the computer. (
http://www.fantasia35.com/images/wifi-05.jpg )
The key factor regarding the decision to mount the bridge near the top of
the mast relates to the fact that at the 2.4 GHz frequency of the 802.11g
wifi bridge, a significant signal loss in the transmit and receive modes
will be experienced with a transmission line in the 60 foot range. When one
compares the losses found in a standard Wifi access point with an integrated
antenna the total cable loss values may be considered zero. This is because
the antenna attached to the access point is about 1 inch from the
transceiver.

If I understand your intentions, you plan to install a high gain mast top
802.11g antenna and locate the bridge or access point down below. You
therefore will be forced to use a coax cable at least 60 feet in length and
will therefore experience significant signal losses. These cable losses
reduce the signal energy between the radio base station and the antenna. For
example a low loss antenna cable has a loss of 0.23 dB per foot at 2.4 GHz.
Standard loss cable is often closer to 1 dB per foot. For cable runs less
than roughly 10 feet the default value of 3 dB can be used assuming you are
using a top quality (and expensive) coaxial cable type.
The bottom line here is why use a coaxial cable where significant signal
losses will be present versus using a cat-5 cable to achieve the desired
antenna height. The theory supporting the significant signal loss at 2.4 GHz
over a 60-foot coaxial cable is as follows. The electrical resistance is in
a cable is the result of opposition to the movement of electrons. The power
output of a cable can be derived from Ohm's and Watt's laws when the voltage
is not alternating (DC current.) When a signal is alternating (at, for
example, 2.4 GHz) the moving electrons tend to push away from the core of
the conducting cable and move towards the outside of the cable. This is
called the skin effect. In essence, it's as though the cable had less
cross-sectional area than the area that is actually present. Skin effect
causes the current to occupy a smaller cross-sectional area. Consequently,
the relative resistance to current flow is greater for alternating current
than for direct current.




"Skip Gundlach" skipgundlach sez use my name at earthlink dot fishcatcher
(net) - with apologies for the spamtrap wrote in message
...
Hi, David, and group(s),

The solution I described will not use the wifi receiver internal to your
laptop due to the limitations I described in my earlier post. Instead
will
use your laptop's Ethernet connection, which runs into a simple POE
interface box. (See the following url for the POE wiring instructions
http://www.nycwireless.net/poe/ ).

Thanks for the link. Below, you may see why this might not be needed for
my
setup.

The input to this POE box is dc power and the Ethernet connection from
your
computer. The DC power comes from the AP or Bridge supplied power
adapter.
The output of the POE box is a cat-5 Ethernet cable spanning up to 300
feet
in length. This cable runs to your nema enclosure and now combines the DC
power and Ethernet.



If your access point or bridge is compatible with the IEEE 802.3af
standard
one simply plugs the cat-5 cable into the AP or Bridge Ethernet
connector.
If you do not have a compatible AP or Bridge one simply splits off the DC
power and wires it directly to the PCB's dc input power terminals.



This solution works equally well irrespective of the use of a desktop (
http://www.fantasia35.com/images/nav-1-03.jpg ) or laptop computer within
your vessel.



I hope this clarifies my wifi implementation strategy.

Indeed. Are you up and running with it? Do you have an antenna stick
mounted on the mast?

You may not recall, but the F35s were on our short list. I recall seeing
your setup in the website until we actually got aboard one and found that
we
were unable to adequately address the stern berth (see the forum archives
for discussion). Your boat looks to be an absolutely marvelous example of
the type.

As much as might be achieved, I'm even, now, considering doing up-the-mast
with a cat5 (or any other 12V) feed to a bridge in a waterproof (NEMA)
box,
thence to an external antenna
http://www.keenansystems.com/store/c...1401cfa1d316d4

and

http://www.keenansystems.com/store/c...1401cfa1d316d4
an 8.5 dB gain antenna atop the mast just above the box.

There's some potential for a couple of miles, and the added enhancement of
our ability to use our laptop ashore, communicating with the boat, or, of
course, both the nav and topsides (the one we'd carry ashore, if we had
to)
computers on at the same time if we cared to do so.

I'm also looking into fab-corp.com products as potentially having more
gain
in the antenna portions. They may also have some bridge solutions, but I
have not yet had a response to my query about their total solution ideas.

However, as attractive as cat5 is for getting signal up the mast, it makes
me tied to the boat as I understand your setup. For that reason, I don't
know that I'd pursue that. *IF* - maybe a big "if" - I can make this
work,
I'd be able to see that bridge from anywhere on or even pretty far away
from
the boat, with either of the two laptops (one "shoreside use" and other
"nav
use" we expect to have aboard. So, aboard could be in communication with
shoreside via IM, for example, or, better (for our circumstances), we
could
be in communication with anyone in the world via VOiP. My current
carrier,
Vonage, has a "softphone" feature which is in the computer; tying in with
a
headset/mike combo makes for better sound than the speaker and built-in
mike. If we had a reliable connection, we could be on the phone anywhere
we
had access, something which is *very* attractive to Lydia, who has 4"
Stainless Steel Hawsers for apron strings...

Back to the cat5, though, if you look at the URLs for Keenan, I'm
wondering
if what you're saying is that one uses cat5 to get signal to the masthead,
and powering the bridge is a coincidence of the cat5 connection from the
comptuter. Might one power a wireless bridge (which would then see my
laptop sitting on the boat somewhere) and put the signal up the mast to
the
antenna at the top? I'd sure rather have the bridge below than in a NEMA
box at the top...

Thanks again for the input (all who have contributed, too!).

L8R

Skip, refitting as fast as I can...

Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"Twenty years from now you will be more disappointed by the things you
didn't do than by the ones you did do. So throw off the bowlines. Sail
away from the safe harbor. Catch the trade winds in your sails. Explore.
Dream. Discover." - Mark Twain

Hi, David, and group(s),

If I understand your intentions, you plan to install a high gain mast top
802.11g antenna and locate the bridge or access point down below. You

No...

I'm thinking in terms of mounting the bridge in a NEMA enclosure, feeding it
voltage from below, and using it to feed a 1' or less coax attached to the
antenna.

( As much as might be achieved, I'm even, now, considering doing
up-the-mast
with a cat5 (or any other 12V) feed to a bridge in a waterproof (NEMA)
box,
thence to an external antenna

http://www.keenansystems.com/store/c...1401cfa1d316d4

and


http://www.keenansystems.com/store/c...1401cfa1d316d4
an 8.5 dB gain antenna atop the mast just above the box.
)

Just where to mount the antenna is still up in the air (so to speak), as the
specs call for a 2" mast; I'd originally thought to put it on the NEMA box
top, keeping the coax inside, too.

However, it may be that a flush mount base isn't possible, in which case I'd
have to consider other means. A 2" pole on the side of the mast isn't an
attractive thought, let alone an attractive sight!

therefore will be forced to use a coax cable at least 60 feet in length
and
will therefore experience significant signal losses. These cable losses

Yah, I know, which is why I don't want to do that...

The thought (maybe as unattainable as perpetual motion) was to provide much
greater reception on the boat, and have a repeater as a side benefit. OTOH,
still researching, thus not knowing the answer, if my laptop can't see the
up-the-mast antenna/repeater from the deck or below, I'm still stuck with
getting a signal below, somehow.

However, with all that gain, perhaps the narrow broadcast width would be
moot and my built-in wifi would pick it up. More research is required...

L8R

Skip


--
Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"Believe me, my young friend, there is *nothing*-absolutely
nothing-half so much worth doing as simply messing,
messing-about-in-boats; messing about in boats-or *with* boats. In or
out of 'em, it doesn't matter. Nothing seems really to matter, that's
the charm of it. Whether you get away, or whether you don't; whether
you arrive at your destination or whether you reach somewhere else, or
whether you never get anywhere at all, you're always busy, and you
never do anything in particular; and when you've done it there's always
something else to do, and you can do it if you like, but you'd much
better not."

Skip,

I plan to fabricate a custom enclosure with the same footprint as my
existing mast top cap. All of the existing lights and transducers currently
mounted up there with the addition of the wifi antenna will then be mounted
a little higher and on top of the enclosure assembly. It will be designed
light weight and such that access to the wifi pcb, if necessary, can be
achieved without moving anything else I mount on the enclosure.

Let me know what you finally do for your application as it sounds like yours
will be permanently mounted before my system is complete.

David



"Skip Gundlach" skipgundlach sez use my name at earthlink dot fishcatcher
(net) - with apologies for the spamtrap wrote in message
...
Hi, David, and group(s),

If I understand your intentions, you plan to install a high gain mast top
802.11g antenna and locate the bridge or access point down below. You

No...

I'm thinking in terms of mounting the bridge in a NEMA enclosure, feeding
it
voltage from below, and using it to feed a 1' or less coax attached to the
antenna.

( As much as might be achieved, I'm even, now, considering doing
up-the-mast
with a cat5 (or any other 12V) feed to a bridge in a waterproof (NEMA)
box,
thence to an external antenna

http://www.keenansystems.com/store/c...1401cfa1d316d4

and


http://www.keenansystems.com/store/c...1401cfa1d316d4
an 8.5 dB gain antenna atop the mast just above the box.
)

Just where to mount the antenna is still up in the air (so to speak), as
the
specs call for a 2" mast; I'd originally thought to put it on the NEMA box
top, keeping the coax inside, too.

However, it may be that a flush mount base isn't possible, in which case
I'd
have to consider other means. A 2" pole on the side of the mast isn't an
attractive thought, let alone an attractive sight!

therefore will be forced to use a coax cable at least 60 feet in length
and
will therefore experience significant signal losses. These cable losses

Yah, I know, which is why I don't want to do that...

The thought (maybe as unattainable as perpetual motion) was to provide
much
greater reception on the boat, and have a repeater as a side benefit.
OTOH,
still researching, thus not knowing the answer, if my laptop can't see the
up-the-mast antenna/repeater from the deck or below, I'm still stuck with
getting a signal below, somehow.

However, with all that gain, perhaps the narrow broadcast width would be
moot and my built-in wifi would pick it up. More research is required...

L8R

Skip


--
Morgan 461 #2
SV Flying Pig
http://tinyurl.com/384p2

"Believe me, my young friend, there is *nothing*-absolutely
nothing-half so much worth doing as simply messing,
messing-about-in-boats; messing about in boats-or *with* boats. In or
out of 'em, it doesn't matter. Nothing seems really to matter, that's
the charm of it. Whether you get away, or whether you don't; whether
you arrive at your destination or whether you reach somewhere else, or
whether you never get anywhere at all, you're always busy, and you
never do anything in particular; and when you've done it there's always
something else to do, and you can do it if you like, but you'd much
better not."

I need some help identifying the type of gear I need to do what I want
to accomplish.

I am building a wired network in my boat, using off the shelf components
designed for home use, such as simple wired routers (Netgear, Belkin,
Lynksys, etc).

But I want to be able to access WiFi Internet service, such as available
through the companies that are offering WiFi at marina's, and I want to
be able to access this from any pc on my wired boat-network.

This is the opposite of what is now common in many homes. There we see
the internet (via cable tv or DSL) hardwired into a wireless router,
which then b'casts to outlying pc's. In my case I want wireless
broadcast _into_ my boat-net, and then hardwired to pc's around the
boat.

What is the name of the device I need at the furthest upstream point
(i.e. the receiving unit from the wireless ISP) that the antenna is
connected to? Whatever it is, from there I want to route to 4 locations
in my boat by cable.

I asked this on a wireless usenet group and they got completely
confused, thinking I was trying to do the common household internal
wireless from wired DSL/cable and wondering why I wasn't "getting it."
Finally one guy understood what I wanted and explained it to the others,
but then nobody had any answers. I am hoping my fellow boaters
understand what I am trying to do.

TIA

Mark

wrote in
:

But I want to be able to access WiFi Internet service, such as available
through the companies that are offering WiFi at marina's, and I want to
be able to access this from any pc on my wired boat-network.


The device you are looking for is a wireless router with point-to-
multipoint access, such as:
http://www.keenansystems.com/store/c...roducts_id=24&
osCsid=10e3853817a6eb3903e357bb5714a47e

The point to multipoint bridge acts as a wireless repeater to connect your
little notebook's pitiful low-powered PCMCIA wireless card to any area wifi
nodes within its range. This particular unit runs the full FCC limit of
200 milliwatts of power and can be configured to an external high gain
antenna, such as:
http://www.keenansystems.com/store/c...roducts_id=19&
osCsid=10e3853817a6eb3903e357bb5714a47e
an 8.5 dBi (about 6.5 dB stronger than a simple vertical dipole) that
remotely mounts to a 2" pipe atop your mast, if you're so inclined. At 50'
this should give you 5 miles of coverage area from your repeater to a wifi
node ashore....quite a bit further than the 300' you can get from the
notebook.

The unit has a single RJ-45 10/100 Ethernet LAN port which you would hook
to your system router's WAN port, similar to connecting a router to cable
or DSL modem at home. This will light up all your wired computers aboard
with access to the repeater via Ethernet, while simultaneously and
independently hooking up your wireless devices through the repeater to the
wifi, without being wired to the boat LAN.

As 2400 Mhz is NOT coax cable friendly at such a high frequency, it's best
to wire Ethernet up to the top of the mast where the antenna is and mount
this repeater in a weatherproof enclosure right under the antenna stick.
This nearly eliminates RF losses between the unit and its external antenna.
The Ethernet cabling to your router can be very long, indeed, with no loss
you can measure. There is also an Ethernet power injector that will
provide 48VDC to the mast-mounted repeater right through the Ethernet cable
the data comes through:
http://www.keenansystems.com/store/c...Path=3&product
s_id=16
As the use of this injector runs off 115VAC, you'll have to provide some
kind of inverter power if you want to run it away from the dock off your
house batteries. If you have 12VDC atop the mast you can switch on
independently from the nav lighting, using a 3A 12V IC regulator bolted to
the metal weatherproof box off your DC boat power will provide direct DC
power to the 11V port on the repeater without inverter or Ethernet
injector.....

As of 2 days ago, there seems to be an out-of-stock situation at this
vendor, but you can hunt around the net for the model number and buy it
from whomever you like.....

One of the regular posters here and I have been emailing each other in
plans to simply put the repeater and 8.5 dBi antenna atop his mast with no
Ethernet wiring to extend the range of his laptops on the boat, wirelessly.
It's a great idea because everyone I know who has a little notebook
wireless on their boat nearly has to be on top of a marina repeater to get
reliable service....

THANK YOU VERY MUCH!

(At last, somebody who understands. I've seen so many eyes go soft focus
about this).

wrote in
:

THANK YOU VERY MUCH!

(At last, somebody who understands. I've seen so many eyes go soft focus
about this).




Great....Let us know what you install and how it works, especially its
range...

Would this work?

http://cgi.ebay.com/ws/eBayISAPI.dll...tem=5766659679