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wifi improvement
I'm looking for experience with external antenna solutions to very flaky
wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Topsides, the range is only flaky, but at least I can pull and send stuff, albeit I have to choose my moments. However, the screen is invisible in anything between dawn and dusk and the keyboard is invisible in the dark, limiting me severely in timing/scheduling. So, I'd like to be able to go below, where there's no reception, not to mention, protection from the elements. Who's used what (up the mast isn't what I had in mind, though if it made sense (I can't imagine it would, financially), I'd look at that) in the line of plug-in remote antennas? I've lost the link, but I saw something which was an antenna for those laptops without wifi, on some unknown length of USB lead; one can buy "active" USB extensions for not too much, which I assume would make it feasible for me to put the antenna out the hatch while I'm at the nav, for example... Thanks for any real-world experience... 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 |
On Thu, 31 Mar 2005 10:30:43 -0500, "Skip Gundlach" skipgundlach sez
use my name at earthlink dot fishcatcher (net) - with apologies for the spamtrap wrote: I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. One solution is to use a wifi pcmcia card that allows external antennas. I use the Orinoco Gold Classic now marketed by Agere. When I bought it, it was one of the very few cards supported by Netstumbler, which I wanted to play with. Now there are a fair number, but I'm satisfied with the Orinoco. Pretty old technology now, though. Probably not up to date with the latest security improvements. It does support an external antenna; few do. Without an antenna, your range is variable, typically from a hundred feet to a few hundred yards. As for antennae, many people recommend what are called "Cantennas" about the size and shape of a Pringles can. The original model actually was a Pringles can. These are yagis, with some wave guide types, that look very similar and seem to have similar specs and are widely available on Ebay. These are OK in the slip, but useless at anchor. They are highly directional, with only about a 30-45 degree beam spread. They claim 12-17 db gain. There are omni directional whips made for car use and boast about 7 db gain, with a magnetic base. I recently saw a 4 ft pole-mount whip omni antenna that claims 12 db gain. I haven't actually tried any of these antennae yet, I'm still in research mode. 802.11b and 802.11g use the same antenna. 802.11a uses a different frequency, but you won't see many 802.11a networks. The tricky part are the connectors. Each antenna has a connector (commonly N type), each card has a connector (varies by brand, with MC type perhaps being most commonly seen in the field.) They are seldom compatible. The antenna vendors offer pigtails for the conversion. The typical pigtail is about 5 feet long. This is not acceptable for boat use, IMHO. First 5 feet is not long enough, but the cable normally used is fairly high loss. I don't have the specs onhand, but if you need a longer cable, research low loss cables. Don't just daisy chain a couple of 5 footers. Also, the connectors on many cards are notoriously unreliable. They wear a bit every time you remove and replace the cable, sometimes needing repair or replacement after about 20 uses. One solution is to buy a short (1 foot) pigtail and "glue" it to the card with silicone. Then use whatever length of low loss cable you need to get to the antenna. Hope this helps; Glen __________________________________________________ __________ Glen "Wiley" Wilson usenet1 SPAMNIX at world wide wiley dot com To reply, lose the capitals and do the obvious. Take a look at cpRepeater, my NMEA data integrator, repeater, and logger at http://www.worldwidewiley.com/ |
"Skip Gundlach" skipgundlach sez use my name at earthlink dot
fishcatcher (net) - with apologies for the spamtrap wrote: I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Topsides, the range is only flaky, but at least I can pull and send stuff, albeit I have to choose my moments. However, the screen is invisible in anything between dawn and dusk and the keyboard is invisible in the dark, limiting me severely in timing/scheduling. It would be easier IMHO for you to learn to touch type for at night. Since the screen is visible, you can see if you make a mistake. Or clip a battery operated light onto the screen if touch typing is too hard for you. And put a hood over the screen for daytime. Our PC is in a box in the cockpit (made of marine plywood and faced with that counter material (melamine or something like that) which he had left over from another project. We have it set up that way so we can use the navigation software on it in lieu of a chart-plotter. I can't type on it very well like that because it is awkwardly positioned, but your box doesn't have to be made of plywood and installed permanently. A cardboard box would do. So, I'd like to be able to go below, where there's no reception, not to mention, protection from the elements. I have used wifi on the boat, and sometimes, after I've logged on the first couple of times, and gotten the PC 'used to it', it will also connect in the cabin. Places where I have connected in the cabin include Deltaville and Charleston Harbor Marina. I just refuse to accept that I can't be more comfortable. It often says the signal is weak, but it doesn't seem to make any real difference. I have my own wireless set-up for the house, and the computer will tell me that the signal strength is low or that the signal strength is very good at different times even though neither I nor the wifi have moved. I don't know why. You do have to have some kind of signal at the boat for this to work. I've also been places where there was a wi-fi, but it was restricted to the office of the marina and/or the deck outside, and I couldn't get the signal at the dock, let alone the boat. This is the case at the Bellhaven Waterway Marina, and the Oriental Marina. Who's used what (up the mast isn't what I had in mind, though if it made sense (I can't imagine it would, financially), I'd look at that) in the line of plug-in remote antennas? I've lost the link, but I saw something which was an antenna for those laptops without wifi, on some unknown length of USB lead; one can buy "active" USB extensions for not too much, which I assume would make it feasible for me to put the antenna out the hatch while I'm at the nav, for example... Thanks for any real-world experience... L8R Skip grandma Rosalie |
Skip -
I have been thru several iterations. My recommendations: 1. Get a 200 mw wifi PCMCIA card, instead of the standard 30 mw card. SMC used to make one - don't know who else does. The SMC card is set up for both internal and external antenna. 2. Get an external antenna. I use a 5 db gain stacked vertical: http://www.fab-corp.com/ (look down the page for the 5.5 db gain with the MMCX connector - this fits the SMC card) - costs $11 3. Add a reflector. This one is cheap, easy to build, and _very_ effective: http://www.freeantennas.com/projects/template/. It can be built with much more gain than a cantenna. My first version I made from cardboard with aluminum foil taped over it - took about 15 minutes to build, and gave approx 18 db gain above the 5 db stacked vertical. Having proved the concept, I have a more permanent version now ;^) bob s/v Eolian, DE45 #11 Seattle On Thu, 31 Mar 2005, it was written: I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Topsides, the range is only flaky, but at least I can pull and send stuff, albeit I have to choose my moments. However, the screen is invisible in anything between dawn and dusk and the keyboard is invisible in the dark, limiting me severely in timing/scheduling. So, I'd like to be able to go below, where there's no reception, not to mention, protection from the elements. Who's used what (up the mast isn't what I had in mind, though if it made sense (I can't imagine it would, financially), I'd look at that) in the line of plug-in remote antennas? I've lost the link, but I saw something which was an antenna for those laptops without wifi, on some unknown length of USB lead; one can buy "active" USB extensions for not too much, which I assume would make it feasible for me to put the antenna out the hatch while I'm at the nav, for example... Thanks for any real-world experience... 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 |
"Skip Gundlach" wrote
I'm looking for experience with external antenna solutions http://www.jefatech.com/ (Temporarily closed) http://www.turnpoint.net/wireless/cantennahowto.html http://flakey.info/antenna/waveguide/#list_of_tins |
On Thu, 31 Mar 2005 10:30:43 -0500, "Skip Gundlach" skipgundlach sez use my name at earthlink dot fishcatcher (net) - with apologies for the spamtrap wrote: I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Thanks for any real-world experience... L8R Skip I use this Linksys USB wifi adapter. You can put a pretty long usb cord on it. Works great for me. http://www.linksys.com/products/prod...id=44&prid=435 Jeannette aa6jh Bristol 32, Puerto Escondido http://www.eblw.com/contepartiro/contepartiro.html |
Skip Gundlach wrote:
I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Topsides, the range is only flaky, but at least I can pull and send stuff, albeit I have to choose my moments. However, the screen is invisible in anything between dawn and dusk and the keyboard is invisible in the dark, limiting me severely in timing/scheduling. So, I'd like to be able to go below, where there's no reception, not to mention, protection from the elements. Who's used what (up the mast isn't what I had in mind, though if it made sense (I can't imagine it would, financially), I'd look at that) in the line of plug-in remote antennas? I've lost the link, but I saw something which was an antenna for those laptops without wifi, on some unknown length of USB lead; one can buy "active" USB extensions for not too much, which I assume would make it feasible for me to put the antenna out the hatch while I'm at the nav, for example... Thanks for any real-world experience... L8R Skip For another avenue, try Verizon's "AirCard". THeir service is excellent, and works anywhere there is Verizon cell service (nearly). -- The constitution promises freedom OF religion, not freedom FROM religion. Think about it, It ain't that hard to figure out. If your religion is none, then deal with it. I strongly urge everyone reading this to check out WWW.anysoldier.com, and support our troops with a letter, a package or a donation. |
"Skip Gundlach" skipgundlach sez use my name at earthlink dot
fishcatcher (net) - with apologies for the spamtrap wrote in : I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Here, have some fun while you're playing with it.... http://www.oreillynet.com/cs/weblog/view/wlg/448 My wireless router is 50' up a tree inside an inverted plastic bucket to keep it out of the rain. It's a Netgear with diversity antennas and receiver. The boys on the air force base enlisted housing about a mile away get great access to it with the Pringles Antenna featured in this article. There's several Pringles Antennas on the roof over there. It's what I do to "support our troops"...(c; Here's lots more antennas for your wireless routers: http://www.turnpoint.net/wireless/has.html The Pringles Antenna is a sharp little "beam", which is great because in a city environment where there are lots of competing wireless signals, you can POINT it at the node you want to hear, and it reject very well all the nodes it's not pointed to. The added 12 dB gain for your miserable little, FCC-hobbled transmitter gives your output signal to that node a real boost, too! Remember - ALTITUDE IS OUR FRIEND on microwave frequencies like 2400 Mhz. It's why the telephone company's microwave antennas were way up a tall tower! |
Skip Gundlach (net) wrote:
I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. I use Broadband Express here in the Northwest and Canada. I bought their P{CMIA card as well as there omni directional antenna and have received signals over half a mile away. Works great and I can almost always get a signal if I anchor in populated harbors. http://www.bbxpress.net Casey Jones s/v Baba 35 lying Eagle Harbor, WA |
Skip Gundlach (net) wrote:
I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. I use Broadband Express here in the Northwest and Canada. I bought their P{CMIA card as well as there omni directional antenna and have received signals over half a mile away. Works great and I can almost always get a signal if I anchor in populated harbors. http://www.bbxpress.net Casey Jones s/v Baba 35 lying Eagle Harbor, WA |
I recently upgraded from their PCMCIA cart and interior antennae to the
networked boat solution because I needed the altitude of an exterior antennae and to get away from that fragile jack on the card. The system works outstandingly for me, but both the price (even at big discount) and the documentation are ludicrous. john "Casey Jones" wrote in message oups.com... Skip Gundlach (net) wrote: I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. I use Broadband Express here in the Northwest and Canada. I bought their P{CMIA card as well as there omni directional antenna and have received signals over half a mile away. Works great and I can almost always get a signal if I anchor in populated harbors. http://www.bbxpress.net Casey Jones s/v Baba 35 lying Eagle Harbor, WA |
I'd get a 200mW PCMCIA card and an external antenna. For Marine
Wireless http://www.marinewireless.us we use a 200mW Engenius card http://www.keenansystems.com/store/c...?products_id=6 with an external antenna. Granted we use it to transmit navigation data wirelessly on large vessels but the reason we use that combo is for it's strong signal and great reception. -Todd Free boat blogs: http://boatblogger.com |
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 "Skip Gundlach" skipgundlach sez use my name at earthlink dot fishcatcher (net) - with apologies for the spamtrap wrote in message ... I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Topsides, the range is only flaky, but at least I can pull and send stuff, albeit I have to choose my moments. However, the screen is invisible in anything between dawn and dusk and the keyboard is invisible in the dark, limiting me severely in timing/scheduling. So, I'd like to be able to go below, where there's no reception, not to mention, protection from the elements. Who's used what (up the mast isn't what I had in mind, though if it made sense (I can't imagine it would, financially), I'd look at that) in the line of plug-in remote antennas? I've lost the link, but I saw something which was an antenna for those laptops without wifi, on some unknown length of USB lead; one can buy "active" USB extensions for not too much, which I assume would make it feasible for me to put the antenna out the hatch while I'm at the nav, for example... Thanks for any real-world experience... 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 |
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 |
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.... |
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THANK YOU VERY MUCH!
(At last, somebody who understands. I've seen so many eyes go soft focus about this). |
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Update, original left below for reference:
I bought a Hawking USB directional antenna along with an active USB cable, which has allowed me to sit at the nav, with the antenna topsides, and enjoy full connectivity, including my Vonage Softphone (drop me a line if you'd like a referral; we'd both get a free month). Unfortunately, as it's not my ISP, I don't have convenient (I consider anything web-based to be extremely inconvenient, so googlegroups is a last resort) access to this group - thus my long disappearances, as I am on the boat, refitting, now, the vast majority of the time. On order, now, is a wireless access point feeding a wireless amplifier, both with pigtails to externally mounted antennas on the NEMA box. The rubber duck from the hub goes down; there's a pigtail of Cat5 communicating with the amplifier which has a bulkhead mounted pigtail onto which the external big-stick 8.5dBi antenna screws. Here's the specs: Special Order Custom Built Dual Radio 2611CB3+D w/ HGV-2409U Antenna D-link 900AP w/rubber duck Antenna Aluminum NEMA Enclusure lightning protection Powering the whole thing with 12V, I'm going to test it out here at home, first, and, assuming all goes well, mount it to the mast the next trip (Monday). All indications are that wherever there's an open wifi signal within a few miles of my anchorage, we'll be on the internet, and on the telephone, transparently as though we were here at home (which is under option contract to sell, so "home" is more a landside term than an abode). This will greatly relieve Lydia's need to be in constant contact with her children, and encourage me, who expected to have only sailmail/winlink and cafe access to minibits of emails. The refit process is coming along very slowly, but it appears that we may be able to bring many things together at the same time. When anything's finished, I'll post about it and provide picture links. In the meantime, for any who may have an interest, clicking on the URL in the sig, and going to the home portion of the gallery will let you see the projects section. 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 Gundlach" skipgundlach sez use my name at earthlink dot fishcatcher (net) - with apologies for the spamtrap wrote in message ... I'm looking for experience with external antenna solutions to very flaky wifi access on the boat. There's every sort of hub range improver (get your signal out to others better) but I don't see much, if anything of the other way around. Topsides, the range is only flaky, but at least I can pull and send stuff, albeit I have to choose my moments. However, the screen is invisible in anything between dawn and dusk and the keyboard is invisible in the dark, limiting me severely in timing/scheduling. So, I'd like to be able to go below, where there's no reception, not to mention, protection from the elements. Who's used what (up the mast isn't what I had in mind, though if it made sense (I can't imagine it would, financially), I'd look at that) in the line of plug-in remote antennas? I've lost the link, but I saw something which was an antenna for those laptops without wifi, on some unknown length of USB lead; one can buy "active" USB extensions for not too much, which I assume would make it feasible for me to put the antenna out the hatch while I'm at the nav, for example... Thanks for any real-world experience... 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 |
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