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Old 25-11-2009, 08:25   #316
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Originally Posted by hellosailor View Post
"Not a problem with gel filled in the standing part but the RJ45 connectors are vulnerable."
Very true, but wrapping the connections may not help since you can't get a vapor-proof seal over the entire connection inside and out.
What you need for this is a good quality RJ45 to begin with, a brand name not "generic Chinese". All RJ45 connectors that I have seen are gold flashed to prevent corrosion but I've seen moist air eat through that in semi-exposed (i.e. patio) locations. So pick the good stuff, and then ADD SILICON JELLY (silicon grease, high temperature dieelctric grease, brake grease, whatever your prefer to call it) before you pop in the RJ45 plug. That's really the key ingredient, the silicon jelly will give you the 100% waterproofing that you need on the actual connections. Put it in the fitting before you make the crimp as well.
Something like $8 for an ounce Ancor brand at West, or $4 for six ounces at an auto parts shop, as "brake grease". Which is probably not quite the same high spec--but appears to be perfectly good for the job.
Regular Vaseline (petrolatum) works great, and is actually what is used in underwater cables.
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Old 04-12-2009, 15:22   #317
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I work in IT so I thought I would ask one of my suppliers who specializes in the physical layer of networks i.e. cabling and wireless equipment. He made a good suggestion regarding the use of the Ubiquity Bullet with a POE (Power of Ethernet) device...

He mentioned that typically the POE device would be plugged into 110v and then use a transformer that steps down and rectifies that to 12 VDC....so possibly the POE could be connected directly to 12 VDC...

Has anyone done this?
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Old 04-12-2009, 16:57   #318
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Originally Posted by LuvToSail View Post
I work in IT so I thought I would ask one of my suppliers who specializes in the physical layer of networks i.e. cabling and wireless equipment. He made a good suggestion regarding the use of the Ubiquity Bullet with a POE (Power of Ethernet) device...

He mentioned that typically the POE device would be plugged into 110v and then use a transformer that steps down and rectifies that to 12 VDC....so possibly the POE could be connected directly to 12 VDC...

Has anyone done this?
All the ubiquiti gear will run fine off ships nominal 12 volts.
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Old 04-12-2009, 17:34   #319
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Sure. Bullets work on anything from 12 to 24VDC. I have set up 3 boats doing it off ships power right now. Also have 3 or 4 land based APs running at 18V off 110VAC wall warts and don't see any difference in performance other than occasionally a short outage in the island's power system causing a reset to default configuration. In view of that, the ones working off ship's power are more reliable.
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Old 04-12-2009, 20:19   #320
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The whole concept behind POE is that the power SUPPLY is much higher voltage than the devices will need. The spec is something ridiculously high (36v? 48 v?) compared to the 5-12v that most solid state "boxes" will actually run on, and that's to ensure that line losses can also be very high and the box will still see way more voltage than it needs to run on. The box (device) always winds up doing the final voltage regulation to reconcile "ridiculously high" with "try not to blow up the box".

So, using ship's power at 11-14.4VDC as the POE supply directly, is perfectly within the range of POE equipment. As long as the equipment doesn't actually require more voltage than what reaches it, i.e. if the box really needs 12VDC and you are only putting 12.2 into a high-loss wire leading a long way to it...It can still be too little voltage. Your mileage may vary, you need to read the specs on the box/device, but the odds are it will work. (And if not, it should just not work--not go poof.)
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Old 06-12-2009, 22:00   #321
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I just finished reading this thread (took me most of the day) and was quite impressed with the knowledge displayed here by W32PAMELA (Bob at Island Time PC), Gashmore, highseas, and many others. I was also pleased that I could still understand most of the technical discussion even having been away from technical stuff (nuclear subs) for many years now.

We are looking for a simple inexpensive system that will enable us to receive wifi at anchor instead of dinghying to shore to call people on Skype and process e-mail. The wife spends up to 4 hours a day on the telephone to clients in the U.S. and sends/receives 15-20 e-mails a day. We will have only one computer connected so don't necessarily need wireless on board.

Distilling and summarizing the advice given in this thread, we can choose from a "system in a box" (5milewifi or BoatWifi.com) or assemble a booster, an antenna, and connecting cables. Obviously putting components together results in many variations but the leading recommended combination currently seems to be a Ubiquiti Bullet 2HP adapter/booster/bridge, a POE injector, gel-filled CAT5 ethernet cable, a short section of LMR400 cable, and an EnGenius 2408 omni antenna. Please correct me if I over-simplified or misinterpreted anyone's recommendations. We would probably want to upgrade the antenna to a 12dBi model since we are on a catamaran.

Questions:
1) Is the extra money to extend effective range of the system really worth it? This question can be translated into geographic terms: Are most anchorages within 1-2 miles of WiFi access points and thus reachable with lower cost units or do we need to spend big bucks on a 5milewifi system?

2) I am debating a "permanent" (drill holes, screw things together, etc.) vs. "temporary" (hang from a signal halyard or lazyjack) installation. Given the short lifetime before obsolesence of today's computer equipment, is "permanently" connecting something necessary or even advisable? Besides being more invasive, permanent mounting requires much more serious waterproofing.

I have a PM out to dlockhart concerning his testing of a system he mentioned in Post #298 above. Hope to hear more from him soon.
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Old 07-12-2009, 05:44   #322
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John,

Sounds like the 2 HP would work well for you. You will not need the "short section of LMR400 cable" as the antenna connects directly to the unit and the unit comes weather proof from the factory.

George
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Old 07-12-2009, 07:08   #323
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Quite frankly, if you are going to be on Skype for 4 hours a day, 2 miles from a boat is pushing it for any of the rigs discussed. To many variables involved to insure a totally reliable connection at a high enough speed for that long. Easy to get much further than that with two narrow beam antennas eyeball to eyeball but you can't keep a narrow beam aimed on a boat and the best shore side APs have a beam width of 120 degrees or more. VOIP takes a lot more bandwidth than e-mail and a little delay doesn't effect web surfing to much but it does effect voice.

If you want masthead mounting stay away from USB adaptors. The DX1100 is basically equivalent to a waterproofed Engeious EUB-362. You would do better with an Alpha and a Tupperware box.

There will probably be something even better introduced about 30 seconds after you buy something but for now the Bullet 2HP is the most cost effective solution I have come across. Small, high power, waterproof, low cost with an excellent user interface.

The MLR400 is not necessary but I prefer adding a short section between the Bullet and the antenna in a masthead installation just to give a little flexibility. The one objection I have to the Bullet is that the case is not what I would call "marine strength". If you don't use any coax let the Bullet hang from the antenna connector with no other mounting that might restrict it moving with the antenna.
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Old 16-12-2009, 18:35   #324
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WiFi

I used Radio Labs last year and was quite disappointed. This year I installed 5 Mile Wifi and was impressed with the difference. The range seems to be actually about two miles and is constant. Currently, it is installed on the stern rail, but will be moved to the top spreader. We'll how well it works. This unit is simple to install and does not interfere with cards, broadband, stc. You can switch from one system to another. This is a good product with good support.
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Old 16-12-2009, 18:43   #325
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A big thanks to the knowledgeable people in this thread. I've put in an order for 2 Ubiquiti Bullet 2HP's, POE injectors, and 2 EnGenius 2408 antennas. I'm planning to set up a base-station on land that has line of sight to most of our anchoring locations.

I have some background in networking, but had never heard of the Ubiquiti stuff. It looks really good, and the AirOS (which I believe is linux-based) is really appealing.

Does anyone know what would be the best modem/antenna combo for cellular 3G(WCDMA) and GSM access?
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Old 16-12-2009, 22:16   #326
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DeWittcap,not quite sure how you can move antenna to top spreader when cable is only 25ft.,and no means of extending without more signal loss.I have the 5mile wifi on 15ft. telescopic pole at stern,have had internet reception up to 7 or 8 miles when sailing coastwise.Trouble with wifi these days, is unsecure signals are dissapearing,what is really needed is a system that automatically gets around security,(without breaking any laws of course).For reliable phone reception,more than a mile or two, 3G is the way to go.
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Old 17-12-2009, 10:00   #327
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wiFi

5 Mile Wifi provides cable of any length and they suggested any loss of signal would be offset by height. Since I sail a lot in Maine, behind the hills, moving the antenna up seems reasonable. I agree there seems to be more "secure" sites appearing, but open sites still abound.
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Old 17-12-2009, 10:16   #328
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5 Mile Wifi provides cable of any length and they suggested any loss of signal would be offset by height.
I believe that is incorect. 50' of the finest LMR400 would cut the signal by more than half. 54% to be exact. Being high helps get around obsticals and widens the fresnel area but it doesn't help that much.

Also they don't specify which "low loss cable". They use an RP-SMA connector which usually fits on LMR240 and smaller. 50' of LMR240 would loose aboutn 34 of the signal.
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Old 17-12-2009, 11:23   #329
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Interesting. Maybe one spreader, @ 15' would be a reasonable compromise.
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Old 20-12-2009, 15:48   #330
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The whole concept behind POE is that the power SUPPLY is much higher voltage than the devices will need. The spec is something ridiculously high (36v? 48 v?) compared to the 5-12v that most solid state "boxes" will actually run on, and that's to ensure that line losses can also be very high and the box will still see way more voltage than it needs to run on. The box (device) always winds up doing the final voltage regulation to reconcile "ridiculously high" with "try not to blow up the box".

So, using ship's power at 11-14.4VDC as the POE supply directly, is perfectly within the range of POE equipment. As long as the equipment doesn't actually require more voltage than what reaches it, i.e. if the box really needs 12VDC and you are only putting 12.2 into a high-loss wire leading a long way to it...It can still be too little voltage. Your mileage may vary, you need to read the specs on the box/device, but the odds are it will work. (And if not, it should just not work--not go poof.)
Regarding PoE. PoE standards claim 300 feet distance but it really depends on what the device needs and can take. Cat5e cable is 24 gauge so doing the calculations if you need a minimum of 9.5V DC at the device and feeding from a 12V DC supply, bank on 60 feet maximum. So find out what the device actually needs in terms of voltage and then see whether the distance will work. Devices that can accept a wide range of voltage 9.5-48V DC are great, no chance of a blow up and you can go up the mast.
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