WiFi Antenna

[Doryman]

Take a look at this marine WiFi antenna package. I am thinking of getting it, especially if I can still use my SBS discount code (PM me if you want to know what it is) but I am wondering (a) how well this kind of antenna works and (b) whether it is a more-expensive repackaging of something I can buy generically elsewhere.

Thanks,
Warren[/url]

[Pat Anderson]

I just Googled "USB WiFi antenna Mac" and got quite a few hits, prices from $50 to $120, so I would think that you could do better than buying from Broadband Xpress!

[Pat Anderson]

This one looks just about right, no?

[starcrafttom]

So are we talking about using this item to increase your reception range of open signals? You still have to have a open wireless router in the area right? or am I missing something??

[Pat Anderson]

Yup. You still need an open wireless access point somewhere in the vicinity. This just increases the range over which you can receive the signal. There is a weak wireless signal, for example, floating over Andrews Bay (several, actually). This theoretically would enhance reception of those signals, and perhaps allow reception of additional signals. I have been amazed at the number of places I have found open access points. I might have to get one of these one of these days.

[ActiveCaptain]

If I read it correctly, it's $350 for a 5 dB antenna, cable, connectors and 802.11 USB modem. That's a lot of money for something that's not going to give you very much.

30 feet of cable plus the connectors will give about a 3-5 dB loss. This means that the antenna isn't really doing anything for you at all - it's just making up for the cable loss (and probably putting your signal a little more in the open and higher). If you're going to go to the trouble of mounting and using and antenna, it should be powerful enough to actually give you something.

To get maximum range, you need a transmitter that outputs 300+ mW and a minimum of a 8-12 dB antenna. You should be able to acquire everything needed for well under $350 with those much more appropriate specs.

[journey on]

Pat,

I'm not sure what the inner workings of the Hawking antenna is/are, but it looks like a parabolic (bowl) antenna, which is directional. And it claims that it is directional. So, if you want to use it you have to point it at the wi-fi transponder. If you're cruising, one rarely knows where the nearest wi-fi transponder is. I'm never certain. An example of a parabolic dish is the sat TV antenna, and that needs to be pointed at the transmitting satellites.

The dipole (stick) antenna offers a flat radiating pattern, with equal power in all horizontal directions ( when the antenna is vertical.) An example is your VHF antenna, which uses this pattern since one doesn't know from which azimuth direction the the signal cometh.

So, get the dipole.

Boris

[jkidd]

Have looked at this in the past Broadband Express is a service with equipment to connect to their towers and marinas. In there brochure they talk about how the number of sites that they have is growing. You can buy simular equipment to boast the distance to free or pay sites. I have equipment running in a city buy SLC that can do 20 miles line of site. That is as long as there are not things causing interference.

[Pat Anderson]

Yes, Boris, you are correct - this one is directional, which probably is a good thing for maximum range. Say you are anchored up and are getting a weak signal. You would try different orientations until you got the strongest signal. You might have to keep reorienting it if you are swinging! The concentration of the signal in the parabola is part of its effectiveness. I saw a plan for a homebrew "tin can" WiFi antenna which presumably would have worked similarly but since my MacBook has no external jack for a WiFi antenna, I would need something that connected through a USB plug. Anything that would enhance the range of the built-in antenna would be a good thing!

[thataway]

I would listen to Jeff Siegel. An excellent article on WiFi from the boat is by Ben Ellison and also refers to Jeff's experiences:
http://powerandmotoryacht.com/columns/electronicsc/0705electronics/

Another source of information is:
http://wireless.wikia.com/wiki/Wi-Fi_on_a_Boat

If I was looking for increased reception, I would start with a Yagi antenna and input that into a reciever/transmitter--bidirectional amplifier (basically a repeater) on the frequency you are picking up. The yagi is best on the 2.4 gig, the parabolic may be better on 5 gig signals (The lower speed 802.11 b, g) are in the 2.4 gigahertz range, then. & N is 5 gigahertz range.

The 802.11 N is inherently a stronger signal, and will have a better range. The latest Mac Books will recieve both b g and N. signals.

Google :802.11b and 802.11g bidirectional amplifier

Basically you have an external antenna on the cabin top, a short cable to the bidirectional amplifier and a second small antenna in the boat which transmits to your Mac Book. Since this is the strongest signal, it will be easy to pick up. All of this will be less than the $350.

[Casey]

At a campground in Key West (last year) I had a very marginal WiFi signal (one bar signal on the laptop). After doing a little googling I bought a hField Technology antenna ( https://www.hfield.com/mm5/merchant.mvc ) and it seemed to help. After doing the installation (software and antenna)the signal strength went to "four bars" and stayed pretty constant.

The antenna looks like a hokey-little-plastic-thing; but seems to work.

Casey
C-Dory Naknek
The Villages, FL
Lake Montezuma, AZ

[Pat Anderson]

Excellent sources of information, I will probably bookmark all of this. I have wireless N at home, and it is awesome. The question is, how much do I have to spend, and how much gear to I have to install, to accomplish what I want to do? An antenna and wireless ethernet bridge on the radar arch would be the cat's meow, but I am already amazed how well I can receive random wireless signals over water with just the internal WiFi antenna in the MacBook (I am connected through a random wireless signal right now in a parking lot in downtown Snoqualmie!), and if a $79 USB gizmo would double or triple that reception, I probably don't need to do more than that for weekend outings and my two or three weeks of cruising a year. On the other hand, if I were a live-aboard, and using this every week, I would no doubt go for the full-meal deal. But great info!

[journey on]

Pat,

What are you doing in a downtown parking lot in Snoq....alimie? Be careful, in LA that could get you arrested (or mugged.)

A friend

[timflan]

I have an Engenius ECB-3220 high-speed, long-range wireless
access point/bridge. Got it last spring, but I didn't end up using it, since I plug my laptop into my T-Mobile phone and use T-Mobile's (slowish) internet-over-cell service.

Here's a link to the item:
http://www.engeniustech.com/datacom/products/details.aspx?id=170

This is a reasonably high-power (400mW RF output power) unit with a small onboard antenna. The included antenna is fine, but mounted to the unit inside the boat, it isn't really as high as it could be. But as-is, you can get it set up and configured, and try it out, BEFORE you upgrade the antenna and run cable for it. It uses a TNC-type antenna connector, so it's no trouble to connect an external cable.

On Two Lucky Fish, I've used this unit as-is on the little overhead shelf, and as you would expect, it detected more networks than my laptop's internal WiFi.

Engenius also makes the same unit inside a ruggedized, waterproof container, but on a C-Dory, I figured, you're more likely to install it belowdecks anyway, so I didn't opt for that model. That model has been discussed on Panbo: http://www.panbo.com/archives/2007/04/engenius_3220ext_wifi_happy_sailor.html

Anyway, before you shell out big bucks, you might consider giving this unit a try.

And I just happen to have one, almost new, in box, complete with all cables and documentation, and it's not accomplishing anything sitting on a shelf at home. The NewEgg price is $105. I'll sell mine for $70 and shipping. [Update: this unit is sold.]

[Captains Cat]

Tim, just sent you a PM about your unit.

Charlie