Is this crap, or will it work? I have no idea. I’ve got the phone company showing up, tomorrow, to install a new connection that I wouldn’t need if I were just a bit closer to the MRT station than I am. This wouldn’t have made that unnecessary, would it?
That’s tiny, this is a wifi dish, works upto 125 miles
that’s a 12 foot dish, and the other end had a 10 foot dish, which your MRT station probably doesn’t have…
Should work fine - I’ve never done it, but i’ve heard plenty of stories of it being done successfully, and the theory is solid.
A couple of years ago, the antenna of choice was an empty pringles can - which would be very easy to test …
I don’t see how it could work.
First of all, it’s certainly not unidirectional like it says because it’s a parabolic dish reflector, which is extremely sensitive to direction! (If you ever watch satellite TV, try moving the dish just one inch in any direction, and your TV screen will go completely blank!)
Also, according to the picture, the USB plug is not at the focus of the dish. It’s sticking out too far for the signal to be reflected into the USB plug. Also, the four electrodes of the USB plug are surrounded by a metal grounding shield, which means it’s impossible for any signal to be reflected from the dish to the four USB electrodes. Instead, the signal be completely blocked by the grounding shield.
And the most ridiculous thing about it is that the USB plug does not have a Wi-Fi signal! The Wi-Fi signal is transmitted though a small antenna which is on your Wi-Fi PCI or PCMCIA card, so in order for a parabolic dish reflector to work, you would have to have a wire from the real Wi-Fi antenna (which is on your PCI or PCMCIA card) to the focal point of the dish.
[quote=“Mark Nagel”]I don’t see how it could work.
First of all, it’s certainly not unidirectional like it says because it’s a parabolic dish reflector, which is extremely sensitive to direction! (If you ever watch satellite TV, try moving the dish just one inch in any direction, and your TV screen will go completely blank!)
Also, according to the picture, the USB plug is not at the focus of the dish. It’s sticking out too far for the signal to be reflected into the USB plug. Also, the four electrodes of the USB plug are surrounded by a metal grounding shield, which means it’s impossible for any signal to be reflected from the dish to the four USB electrodes. Instead, the signal be completely blocked by the grounding shield.
And the most ridiculous thing about it is that the USB plug does not have a Wi-Fi signal! The Wi-Fi signal is transmitted though a small antenna which is on your Wi-Fi PCI or PCMCIA card, so in order for a parabolic dish reflector to work, you would have to have a wire from the real Wi-Fi antenna (which is on your PCI or PCMCIA card) to the focal point of the dish.[/quote]
Is it just me or does this eloquent missive smack of ignorance?
It is not unidirectional in the same was as a Pringles Tube because it is a dish and not a tube therefore it has a wider catchment, which was the point that was being made.
I would like to see the maths to show that his USB is not at the focus. The focus of any dish is not the centre of the dish but a point above that within the bowl of the dish. I thought his USB looked to be in a pretty good place.
You can buy WIFI receivers that are completely housed in a USB unit. I assume that this is what the guy has used. Not everyone uses a PCMCIA card for WIFI. I’ve jumped a little here but my assumption would be that the entire USB device is acting as an antennae and thus if any of it is getting bounced on by signal this should work.
There have been articles about similar devices around for years, surely they work? I might build one just to find out.
Isn’t that what “unidirectional” means? One direction?
[quote=“Mark Nagel”]I don’t see how it could work.
First of all, it’s certainly not unidirectional like it says because it’s a parabolic dish reflector, which is extremely sensitive to direction! (If you ever watch satellite TV, try moving the dish just one inch in any direction, and your TV screen will go completely blank!)[/quote]
‘Unidirectional’ is the correct term.
[quote]Also, according to the picture, the USB plug is not at the focus of the dish. It’s sticking out too far for the signal to be reflected into the USB plug. Also, the four electrodes of the USB plug are surrounded by a metal grounding shield, which means it’s impossible for any signal to be reflected from the dish to the four USB electrodes. Instead, the signal be completely blocked by the grounding shield.
And the most ridiculous thing about it is that the USB plug does not have a Wi-Fi signal! The Wi-Fi signal is transmitted though a small antenna which is on your Wi-Fi PCI or PCMCIA card, so in order for a parabolic dish reflector to work, you would have to have a wire from the real Wi-Fi antenna (which is on your PCI or PCMCIA card) to the focal point of the dish.[/quote]
The USB plug glued into the dish is of course not a Wi-Fi antenna, it’s just the receptacle for a USB Wi-Fi adapter (those that allow older PCs/laptops to connect to Wi-Fi networks and have a antenna built into it). If you plug that into the dish the USB Wi-Fi adapter should sit pretty much in the focus.
There is no doubt about it. You can build a really efficient antenna. But, is it legal? To the best of my knowledge, wifi comes under the same rules that govern cordless phones and other unlicensed radio devices.
I’m not sure how they figure it but factors such as output power, antenna size, range and field strength have to be below certain levels.
But it would be still fun to built and test…
[quote=“Taiwan_Student”]There is no doubt about it. You can build a really efficient antenna. But, is it legal? To the best of my knowledge, wifi comes under the same rules that govern cordless phones and other unlicensed radio devices.
I’m not sure how they figure it but factors such as output power, antenna size, range and field strength have to be below certain levels.
But it would be still fun to built and test…[/quote]There may be limits on broadcasting, but that 125 mile thing I mentioned before was unamplified, just a big dish to make it unidirectional. You can build as big a receiver as you like.