I'm trying to setup a homebrew WiFi (802.11b/g) antenna for my IBM
Think Pad laptop. The coax run will be about 15" going to some home
brew antennas. I don't know the name of the antenna but it can be seen
at this url:

http://wireless.gumph.org/content/4/...s-antenna.html

I plan on running coax (2 lines) from the 802.11 card (internal mini
PCI)
to the rear top of the LCD display. I'll terminate with connectors and
attach the antennas when the laptop is open. Great plan but what about
coax losses? The output of the 802.11 card is 250mw.

Most WiFi antennas use RG174 coax - I've even seen mobile antennas
for WiFi with 10' runs of the stuff. Correct me if I'm wrong but
wouldn't
10' of rg174 at 5 ghz be so lossy that it would defeat the purpose of
the
mag mount mobile antenna?

Like I said, I only need about 15" from the output of the 802.11 card
to the antennas. What coax would be good? I'm worried about losses
but I also need to route the coax through the laptop and up the back
of the LCD display so size (dia) matters. I guess I'm stuck with RG174
but are there better choices? What would be the losses with 15" of it
into a matched load at 5ghz?

Basically, given the above conditions and with the need for both small
coax and teeny connectors, what would be your recommendations?

73's de Ken KG0WX

"KG0WX" wrote in message
oups.com...
I'm trying to setup a homebrew WiFi (802.11b/g) antenna for my IBM
Think Pad laptop. The coax run will be about 15" going to some home
brew antennas. I don't know the name of the antenna but it can be seen
at this url:

http://wireless.gumph.org/content/4/...s-antenna.html

I plan on running coax (2 lines) from the 802.11 card (internal mini
PCI)
to the rear top of the LCD display. I'll terminate with connectors and
attach the antennas when the laptop is open. Great plan but what about
coax losses? The output of the 802.11 card is 250mw.

Most WiFi antennas use RG174 coax - I've even seen mobile antennas
for WiFi with 10' runs of the stuff. Correct me if I'm wrong but
wouldn't
10' of rg174 at 5 ghz be so lossy that it would defeat the purpose of
the
mag mount mobile antenna?

Like I said, I only need about 15" from the output of the 802.11 card
to the antennas. What coax would be good? I'm worried about losses
but I also need to route the coax through the laptop and up the back
of the LCD display so size (dia) matters. I guess I'm stuck with RG174
but are there better choices? What would be the losses with 15" of it
into a matched load at 5ghz?

Basically, given the above conditions and with the need for both small
coax and teeny connectors, what would be your recommendations?

73's de Ken KG0WX

Hi Ken

Could you use a USB connected wireless adapter?? You can dismantel some
USB wireless adapters so their antennas are available to you for attaching a
coax and even a SMA if you have the ability to work with that small stuff.

Jerry

"Jerry Martes" wrote in message
news:NfKRf.7774$%e1.6453@trnddc05...

"KG0WX" wrote in message
oups.com...
I'm trying to setup a homebrew WiFi (802.11b/g) antenna for my IBM
Think Pad laptop. The coax run will be about 15" going to some home
brew antennas. I don't know the name of the antenna but it can be seen
at this url:

http://wireless.gumph.org/content/4/...s-antenna.html

I plan on running coax (2 lines) from the 802.11 card (internal mini
PCI)
to the rear top of the LCD display. I'll terminate with connectors and
attach the antennas when the laptop is open. Great plan but what about
coax losses? The output of the 802.11 card is 250mw.

Most WiFi antennas use RG174 coax - I've even seen mobile antennas
for WiFi with 10' runs of the stuff. Correct me if I'm wrong but
wouldn't
10' of rg174 at 5 ghz be so lossy that it would defeat the purpose of
the
mag mount mobile antenna?

Like I said, I only need about 15" from the output of the 802.11 card
to the antennas. What coax would be good? I'm worried about losses
but I also need to route the coax through the laptop and up the back
of the LCD display so size (dia) matters. I guess I'm stuck with RG174
but are there better choices? What would be the losses with 15" of it
into a matched load at 5ghz?

Basically, given the above conditions and with the need for both small
coax and teeny connectors, what would be your recommendations?

73's de Ken KG0WX

Hi Ken

Could you use a USB connected wireless adapter?? You can dismantel some
USB wireless adapters so their antennas are available to you for attaching
a
coax and even a SMA if you have the ability to work with that small stuff.

Jerry


Hi, Jerry and Ken

Pardon me for getting into this, but we would all like to know which USB
adapters (and cardbus adapters currently manufactured) can be taken apart
and fitted with an antenna connector. There are a number of PC card adapters
that have appeared in websites showing these modifications but the units are
mostly no longer manufactured. With metropolitan Wi-Fi coming in to various
municipalities lately, it is becoming more desirable to put up an antenna to
guarantee 100% connection when the AP is half a block away or behind a big
house or dense foliage.

Thanks for your help.

Chuck

Well, I'm not just building *any* WiFi setup - I researched a bit and
found
on eBay what is generally agreed on to be one of the top 5 internal
802.11
cards. With up to 250mw output and external antenna, I plan on diving
into
a new hobby - wardriving.

I could just buy a USB WiFi adapter and crack open the case and hack it
with an external antenna but from what I've seen, both the low output
and
poor rx sensitivity seem to be quite common with these devices and that
is not what I want.

I did remember a bookmarked site which calculated the info I needed.
Turns
out that my coax in question will have about 1.7 db loss at 5ghz. Not
too bad.

Still, if anyone knows of a coax that is better than RG174 while being
about
the same size, please chime in with your comments!

Ken KG0WX

"Chuck Olson" wrote in message
...

"Jerry Martes" wrote in message
news:NfKRf.7774$%e1.6453@trnddc05...

"KG0WX" wrote in message
oups.com...
I'm trying to setup a homebrew WiFi (802.11b/g) antenna for my IBM
Think Pad laptop. The coax run will be about 15" going to some home
brew antennas. I don't know the name of the antenna but it can be seen
at this url:

http://wireless.gumph.org/content/4/...s-antenna.html

I plan on running coax (2 lines) from the 802.11 card (internal mini
PCI)
to the rear top of the LCD display. I'll terminate with connectors and
attach the antennas when the laptop is open. Great plan but what about
coax losses? The output of the 802.11 card is 250mw.

Most WiFi antennas use RG174 coax - I've even seen mobile antennas
for WiFi with 10' runs of the stuff. Correct me if I'm wrong but
wouldn't
10' of rg174 at 5 ghz be so lossy that it would defeat the purpose of
the
mag mount mobile antenna?

Like I said, I only need about 15" from the output of the 802.11 card
to the antennas. What coax would be good? I'm worried about losses
but I also need to route the coax through the laptop and up the back
of the LCD display so size (dia) matters. I guess I'm stuck with RG174
but are there better choices? What would be the losses with 15" of it
into a matched load at 5ghz?

Basically, given the above conditions and with the need for both small
coax and teeny connectors, what would be your recommendations?

73's de Ken KG0WX

Hi Ken

Could you use a USB connected wireless adapter?? You can dismantel
some
USB wireless adapters so their antennas are available to you for
attaching
a
coax and even a SMA if you have the ability to work with that small
stuff.

Jerry


Hi, Jerry and Ken

Pardon me for getting into this, but we would all like to know which USB
adapters (and cardbus adapters currently manufactured) can be taken apart
and fitted with an antenna connector. There are a number of PC card
adapters
that have appeared in websites showing these modifications but the units
are
mostly no longer manufactured. With metropolitan Wi-Fi coming in to
various
municipalities lately, it is becoming more desirable to put up an antenna
to
guarantee 100% connection when the AP is half a block away or behind a big
house or dense foliage.

Thanks for your help.

Chuck

Hi Chuck

Although I dont have a part number for a USB wireless adapter, I can get
the number from my buddy's adapter. He replaced the built in antenna the
USB wireless adapter with a short coax to his Wireless antenna. I assummed
the adapters are available at places like Fry's.
I am using a different approach here at home. I put a Bridge behind
small satellite TV dish and suffered the loss associated with foot and a
half of coax loss to the illuminator. That allows me to run CAT 5 to the
computer.

Jerry

hmmmm,

Someone does not know how to read. No where in his post did he stated that
he was going to hack the computer system. haha. He did state that he would
hack a USB device. Besides, the true definition of wardrivers are only out
to log and collect information from the wireless access points (WAPs) they
find while driving. The legality of wardriving in the United States is not
clearly defined. There has never been any conviction for wardriving, and
there is the untested argument that the 802.11 and DHCP protocols operate on
behalf of the owner giving consent to use the network, but not if the user
has other reason to know that there is no consent.
"Bob" wrote in message
. com...
Did you know the USSS investigates many types of computer fraud and
hacking? Do you think it’s wise to state your intent to maliciously invade
other peoples computer systems and mention a traceable Ebay purchase of
the goods to do so?
USB type adaptors generally do not work with the popular freeware that you
wanna be hackers use to commit your heinous crimes.
Belden RG-174 has about .6dB loss/ft @ 5.6GHz. Your 15ft chunk would have
about 9dB loss, not too impressive.
Bob


KG0WX wrote:
Well, I'm not just building *any* WiFi setup - I researched a bit and
found
on eBay what is generally agreed on to be one of the top 5 internal
802.11
cards. With up to 250mw output and external antenna, I plan on diving
into
a new hobby - wardriving.

I could just buy a USB WiFi adapter and crack open the case and hack it
with an external antenna but from what I've seen, both the low output
and
poor rx sensitivity seem to be quite common with these devices and that
is not what I want.

I did remember a bookmarked site which calculated the info I needed.
Turns
out that my coax in question will have about 1.7 db loss at 5ghz. Not
too bad.

Still, if anyone knows of a coax that is better than RG174 while being
about
the same size, please chime in with your comments!

Ken KG0WX

Bob wrote in
. com:

Did you know the USSS investigates many types of computer
fraud and hacking? Do you think it’s wise to state your
intent to maliciously invade other peoples computer systems
and mention a traceable Ebay purchase of the goods to do
so? USB type adaptors generally do not work with the
popular freeware that you wanna be hackers use to commit
your heinous crimes. Belden RG-174 has about .6dB loss/ft @
5.6GHz. Your 15ft chunk would have about 9dB loss, not too
impressive. Bob


GOOD Greaf the USSS doesn't care about WARDRIVING, it's a
recieving game not a transmit, besides they don't have time for
that pee-on piddily stuff your calling HENIOUS.

Your acting like this guy staged a circle jerk in the Emergency
Radio Club meeting or something, chill out.
The USSS is the reason I am a member of the NRA.

On 6/4/2011 11:39 PM, moronsbegone wrote:

...
GOOD Greaf the USSS doesn't care about WARDRIVING, it's a
recieving game not a transmit, besides they don't have time for
that pee-on piddily stuff your calling HENIOUS.

Your acting like this guy staged a circle jerk in the Emergency
Radio Club meeting or something, chill out.
The USSS is the reason I am a member of the NRA.



The insanity of it being a crime to receive any radio signal is so
obvious, I can only consider those recognize it as a VALID crime are insane.

However, I have always felt the same, and since a VERY young age, that
making the growing or possession of plants a crime demonstrates EXACTLY
the same brand of insanity.

If you look around, you will find other examples of this same insanity ...

--

Regards,
JS
“The Constitution is not an instrument for the government to restrain
the people, it’s an instrument for the people to restrain the
government.” -- Patrick Henry

On 6/4/2011 11:39 PM, moronsbegone wrote:
wrote in
. com:

Did you know the USSS investigates many types of computer
fraud and hacking? Do you think it’s wise to state your
intent to maliciously invade other peoples computer systems
and mention a traceable Ebay purchase of the goods to do
so? USB type adaptors generally do not work with the
popular freeware that you wanna be hackers use to commit
your heinous crimes. Belden RG-174 has about .6dB loss/ft @
5.6GHz. Your 15ft chunk would have about 9dB loss, not too
impressive. Bob


GOOD Greaf the USSS doesn't care about WARDRIVING, it's a
recieving game not a transmit, besides they don't have time for
that pee-on piddily stuff your calling HENIOUS.

Your acting like this guy staged a circle jerk in the Emergency
Radio Club meeting or something, chill out.
The USSS is the reason I am a member of the NRA.



The insanity of it being a crime to receive any radio signal is so
obvious, I can only consider those recognizing it as a VALID crime are
insane.

However, I have always felt the same, and since a VERY young age, that
making the growing or possession of certain plants a crime demonstrates
EXACTLY the same brand of insanity. The men/groups/etc. establishing
themselves as rightfully being able to command such insanity must think
themselves GOD, how nice!

If you look around, you will find other examples of this same brand of
insanity ... and, if you look even closer, you will find it usually
involves a law which allows some to become very rich from its'
enforcement ... so that in the end, those having the laws forced upon
them are forced into participation in the insanity! As, even the simply
actions to resist those laws, and even solely on principal, brings one
under great scrutiny, or even punitive actions! And, this seems to have
a 1:1 correlation to the "money stream(s)" generated by the law(s.)

But, has little to do with lossy coax at high frequencies ...

--

Regards,
JS
“The Constitution is not an instrument for the government to restrain
the people, it’s an instrument for the people to restrain the
government.” -- Patrick Henry