Long-Distance WiFi Device - Page 21

Jim Newman · 28-10-2009, 13:56

Anyone know how the Repeatit does in comparison?

W32PAMELA · 28-10-2009, 15:45

Quote:

Originally Posted by CarlF

I was getting set to buy a Ubiquiti 2HP when I stumbled across the PicoStation2HP

...The disadvantage is only a 6DBi omni antenna. Am I likely to notice the difference compared to a slighly more directional antenna?Carl

The PicoStation2HP is the same electronics package as the other ubiquiti a/b/g products except with more memory for customizing firmware. The 6dbi rubber ducky antenna is not on par with a commercial grade 8 dbi but you will certainly get your money's worth with the PicoStation, at least up to a couple of miles. You always have the option of adding a better antenna by using a short pigtail if you aren't satisfied with the stock setup.

denverd0n · 29-10-2009, 08:06

One consideration on a sailboat is the rocking (and heeling, if you want to use wireless while actually sailing). This is one reason that very high gain antennas are specifically NOT recommended for sailboat VHFs. As such, the lower gain antenna might, in some cases, actually work better. More so the higher you mount the antenna.

aboutgone · 10-11-2009, 06:51

has anyone used the alfa 1000mW.....amazon has the whole set up for 65.00$

hellosailor · Today, 17:58

From the folks who keep the standard, usb.org:

Q1: How long of a cable can I use to connect my device?
A1: In practice, the USB specification limits the length of a cable between full speed devices to 5 meters (a little under 16 feet 5 inches). For a low speed device the limit is 3 meters (9 feet 10 inches).
Q2: Why can't I use a cable longer than 3 or 5m?
A2: USB's electrical design doesn't allow it. When USB was designed, a decision was made to handle the propagation of electromagnetic fields on USB data lines in a way that limited the maximum length of a USB cable to something in the range of 4m. This method has a number of advantages and, since USB is intended for a desktop environment, the range limitations were deemed acceptable. If you're familiar with transmission line theory and want more detail on this topic, take a look at the USB signals section of the developers FAQ.
Q3: How far away from a PC can I put a USB device?
A3: With the maximum of 5 hubs connected with 5m cables and a 5m cable going to your full speed device, this will give you 30m of cable (see section 7.1.19 for details). With a low speed device, you will be able to get a range up to 27m, depending on how long the device's cable is. With a straightforward cable route, you will probably be able to reach out 25m or so from the PC.

So, the alfa would be a very good deal IF you bear in mind that you will suffer signal loss by using antenna cable, and you'd want to locate the alfa box itself on a longer USB cord. Either a maximum of 5 meters away from your computer (enough to get up on deck) or a bit longer--if you start chaining repeating hubs, which could be a bad idea for several reasons including water intrusion and ugliness.

Maybe put the antenna at the mast base, or on the rail, and with five meters there's enough to run inside to the nav station? Or just use it on a pole, pop it out in the cockpit or hatch when you are at anchor.

28-10-2009, 13:56	#301
Jim Newman Registered User Join Date: Jan 2009 Location: Benenden, Kent, UK Boat: Moody 425, Siempre of Dartmouth Posts: 21	Anyone know how the Repeatit does in comparison? __________________ Jim S/Y Siempre of Dartmouth Moody 425

10-11-2009, 06:51	#304
aboutgone Registered User Join Date: Jun 2009 Location: Cortez,FL. Boat: CSY 44 w/o Primetime Posts: 117	has anyone used the alfa 1000mW.....amazon has the whole set up for 65.00$ __________________ Never start vast projects with half vast ideas

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29-10-2009, 08:06	#303
denverd0n Registered User Join Date: Jun 2008 Posts: 79	One consideration on a sailboat is the rocking (and heeling, if you want to use wireless while actually sailing). This is one reason that very high gain antennas are specifically NOT recommended for sailboat VHFs. As such, the lower gain antenna might, in some cases, actually work better. More so the higher you mount the antenna.

Today, 17:58	#305
hellosailor Registered User Join Date: Apr 2006 Posts: 3,993	From the folks who keep the standard, usb.org: Q1: How long of a cable can I use to connect my device? A1: In practice, the USB specification limits the length of a cable between full speed devices to 5 meters (a little under 16 feet 5 inches). For a low speed device the limit is 3 meters (9 feet 10 inches). Q2: Why can't I use a cable longer than 3 or 5m? A2: USB's electrical design doesn't allow it. When USB was designed, a decision was made to handle the propagation of electromagnetic fields on USB data lines in a way that limited the maximum length of a USB cable to something in the range of 4m. This method has a number of advantages and, since USB is intended for a desktop environment, the range limitations were deemed acceptable. If you're familiar with transmission line theory and want more detail on this topic, take a look at the USB signals section of the developers FAQ. Q3: How far away from a PC can I put a USB device? A3: With the maximum of 5 hubs connected with 5m cables and a 5m cable going to your full speed device, this will give you 30m of cable (see section 7.1.19 for details). With a low speed device, you will be able to get a range up to 27m, depending on how long the device's cable is. With a straightforward cable route, you will probably be able to reach out 25m or so from the PC. So, the alfa would be a very good deal IF you bear in mind that you will suffer signal loss by using antenna cable, and you'd want to locate the alfa box itself on a longer USB cord. Either a maximum of 5 meters away from your computer (enough to get up on deck) or a bit longer--if you start chaining repeating hubs, which could be a bad idea for several reasons including water intrusion and ugliness. Maybe put the antenna at the mast base, or on the rail, and with five meters there's enough to run inside to the nav station? Or just use it on a pole, pop it out in the cockpit or hatch when you are at anchor.