Extending wireless antenna

[atDFN]

I have a customer who is trying to use a wireless connection with her
son's computer. The son is connected to the Belkin wireless router.
However, Mom is living in a 5th-wheel in the back yard. So, she's
surrounded in a metal box. She has a PCI wireless card plugged into
her computer. As soon as I saw where she had her computer, I was
doubtful she'd ever get it to work.

However, Belkin makes an antenna for this card. Problem is, its cable
is only 5 feet long. I've tried getting an answer from Belkin but have
so far been unsuccessful. I want to know if I can extend the cable on
the antenna so I can get the antenna up in front of a window. As a
general rule, does anyone think that would work? I just don't know if
the antenna has to be powered and if the additional cable would help
or hurt.

Thanks.



ben

 

[philo]

I have a customer who is trying to use a wireless connection with her
son's computer. The son is connected to the Belkin wireless router.
However, Mom is living in a 5th-wheel in the back yard. So, she's
surrounded in a metal box. She has a PCI wireless card plugged into
her computer. As soon as I saw where she had her computer, I was
doubtful she'd ever get it to work.

However, Belkin makes an antenna for this card. Problem is, its cable
is only 5 feet long. I've tried getting an answer from Belkin but have
so far been unsuccessful. I want to know if I can extend the cable on
the antenna so I can get the antenna up in front of a window. As a
general rule, does anyone think that would work? I just don't know if
the antenna has to be powered and if the additional cable would help
or hurt.

There should be no problem extending the cable...
hopefully it has a connector and you can get a ready-made extension.

because you are dealing with RF it's best not to just splice-in a new piece
as if it were a lamp cord

 

[atDFN]

There should be no problem extending the cable...
hopefully it has a connector and you can get a ready-made extension.

because you are dealing with RF it's best not to just splice-in a new piece
as if it were a lamp cord

Thanks. No, the add-on antenna from Belkin looks like it's coax.
It's hard to see in the picture, but looks a lot like the cable you
use to run for cable TV. Doesn't look like it has the center wire
extending into the connector, though. I'm also reading about other
powered antennas for wifi.


ben

 

[philo]

Thanks. No, the add-on antenna from Belkin looks like it's coax.
It's hard to see in the picture, but looks a lot like the cable you
use to run for cable TV. Doesn't look like it has the center wire
extending into the connector, though. I'm also reading about other
powered antennas for wifi.

I took a quick look at the Belkin antenna on their website.
the center wire does not show up in the picture...but i'm sure it;s
there...as that has to be
standard coax. You can probably get an extension cable at radio shack or any
electronics
store...it all looks completely standard.

 

[CBFalconer]

There should be no problem extending the cable...
hopefully it has a connector and you can get a ready-made extension.

because you are dealing with RF it's best not to just splice-in a new piece
as if it were a lamp cord

The natural impedance of most antenna systems is 300 ohms, so
without specific information from the manufacturer I would try
extending it with 300 ohm cable. Many systems also use
transformers or baluns to handle less lossy 75 ohm cable, which is
another possibility.

 

[John]

I have a customer who is trying to use a wireless connection with her
son's computer. The son is connected to the Belkin wireless router.
However, Mom is living in a 5th-wheel in the back yard. So, she's
surrounded in a metal box. She has a PCI wireless card plugged into
her computer. As soon as I saw where she had her computer, I was
doubtful she'd ever get it to work.

However, Belkin makes an antenna for this card. Problem is, its cable
is only 5 feet long. I've tried getting an answer from Belkin but have
so far been unsuccessful. I want to know if I can extend the cable on
the antenna so I can get the antenna up in front of a window. As a
general rule, does anyone think that would work? I just don't know if
the antenna has to be powered and if the additional cable would help
or hurt.

Thanks.

I want to get one of those. How much was it? It should be dirt cheap.
Cant find one locally.

Im not sure if it would even help.

I have a PC 28 feet away in another room. When it works it works
great. The speeds etc are actually very good. I can download huge
windows updates etc just like on my cable modem with a regular
connection.

However the microwave kills the signal royally. Ive seen some reviews
where they warn about it but they say it kind of slows it down - not
totally kills the signal. I either have a much more powerful microwave
or something.

Some other things interfere too. Not sure if it would actually make
much difference with interference like that but was thinking about
trying an antenna that sits on the desktop instead of hidden in back
of the big metal PC case at floor level.

 

[kony]

I want to get one of those. How much was it? It should be dirt cheap.
Cant find one locally.

Indeed they "should" be dirt cheap, but usually they aren't, are VERY
expensive for just a thin piece of coax with a couple of (usually)
RSMA connectors on each end. "Should" cost $4, maybe $10 after
typical markup on cables, but they often cost closer to $20... at that
price it's almost worthwhile to just buy a USB version which includes
a 5 ft USB cable, or add your own, longer USB cable.

Im not sure if it would even help.

I have a PC 28 feet away in another room. When it works it works
great. The speeds etc are actually very good. I can download huge
windows updates etc just like on my cable modem with a regular
connection.

However the microwave kills the signal royally. Ive seen some reviews
where they warn about it but they say it kind of slows it down - not
totally kills the signal. I either have a much more powerful microwave
or something.

Some other things interfere too. Not sure if it would actually make
much difference with interference like that but was thinking about
trying an antenna that sits on the desktop instead of hidden in back
of the big metal PC case at floor level.

Getting the antenna out from the back of the PC can definitely help,
though some cards are a lot worse than others... I have some D-Link
PCI cards that have at least 2-3X the range of cheap
Trendware/Xterasys cards in exact same environment.

Something else that can help a weak card is to put a repeater
nearby... it need not be nearly midway inbetween the card and router,
close to the card can work too... I have a Belkin 802.11b router doing
that, without any configuration at all it'll function as a repeater
(though it'd be good to configure for security reasons) only cost ~$10
from a Black Friday sale.

 

[John]

Something else that can help a weak card is to put a repeater
nearby... it need not be nearly midway inbetween the card and router,
close to the card can work too... I have a Belkin 802.11b router doing
that, without any configuration at all it'll function as a repeater
(though it'd be good to configure for security reasons) only cost ~$10
from a Black Friday sale.

I had an extra one but returned it. I got that $10 deal from a black
friday sale but already had one from the month before so I returned
it. I should have kept it.

Office Max is really screwing the people in the state Im in now. None
of the hot deals are offered here since Jan 1.

Its torture reading about everyone getting a 80 gig WD for $20 this
week. Let alone all the free DVD disks and other junk. Exactly what
I needed.

I think the cheapskates are killing the deals though. Too many people
scamming the deals - the stores are starting to crackdown and I dont
blame them. People buying before the sale and then returning and
buying. People buying 6-8 of the same items ! Thats just pissing them
off.

 

[Roby]

I have a customer who is trying to use a wireless connection with her
son's computer. The son is connected to the Belkin wireless router.
However, Mom is living in a 5th-wheel in the back yard. So, she's
surrounded in a metal box. She has a PCI wireless card plugged into
her computer. As soon as I saw where she had her computer, I was
doubtful she'd ever get it to work.

However, Belkin makes an antenna for this card. Problem is, its cable
is only 5 feet long. I've tried getting an answer from Belkin but have
so far been unsuccessful. I want to know if I can extend the cable on
the antenna so I can get the antenna up in front of a window. As a
general rule, does anyone think that would work? I just don't know if
the antenna has to be powered and if the additional cable would help
or hurt.

Thanks.



ben

There is always some signal loss through coaxial cable. At high frequencies
(2 GHz here), there's a lot of loss. Longer cable = more loss. It's
possible that the improved received signal strength gained by putting the
antenna in a better location will be offset by added loss in a longer
cable. There are additional issues with adding an additional piece of
cable to the existing part: the new cable must have the same characteristic
impedance as the rest of the antenna. It also needs to be low-loss cable
designed for microwave applications. All coax is NOT the same.

It isn't necessary to locate the antenna right at the window. Across the
room is as good, provided that the antenna can still "see" the other end of
the link. Perhaps you can make the five foot cable work this way.

How about a directional antenna instead of the omni type?

Roby

 

[atDFN]

There is always some signal loss through coaxial cable. At high frequencies
(2 GHz here), there's a lot of loss. Longer cable = more loss. It's
possible that the improved received signal strength gained by putting the
antenna in a better location will be offset by added loss in a longer
cable. There are additional issues with adding an additional piece of
cable to the existing part: the new cable must have the same characteristic
impedance as the rest of the antenna. It also needs to be low-loss cable
designed for microwave applications. All coax is NOT the same.

It isn't necessary to locate the antenna right at the window. Across the
room is as good, provided that the antenna can still "see" the other end of
the link. Perhaps you can make the five foot cable work this way.

How about a directional antenna instead of the omni type?

Roby

Thanks for the additional information. The positioning of the
computer is very odd. In the cramped setup this customer has in the
5th-wheel, I don't think the antenna is going to help. I've learned a
lot from the responses given. I think she's going to be better off
not trying to do the wireless thing. The other computer is quite a
distance away and at an angle where the signal is having to try to
travel at an angle through all the brick in the house.

She's open to the idea of getting satellite internet. A local
provider has a modem with an exterior antenna.

Again, thanks to everyone. I've collected a lot of information for
the future.


ben