What's happening? I thought everything came out great! but the
BiQuad I just built
doesn't seem to show any increase in signal strength while using
Netstumbler!
I can't see where I went wrong can you? http://img.villagephotos.com/p/2003-...728(Large).JPG
I don't have a piece of wire down in the center stub but I don't think
that matters do you?
How can the center pin be connected to one side of the element
and the other side of the element be connected to the board? Seems
like a short to me.
Thanks guys!
"Knight" <petelarosa@comcast.net> wrote in message
news:1189112594.084875.11090@50g2000hsm.googlegrou ps.com...
> Hey guys,
>
> What's happening? I thought everything came out great! but the
> BiQuad I just built
> doesn't seem to show any increase in signal strength while using
> Netstumbler!
> I can't see where I went wrong can you?
> http://img.villagephotos.com/p/2003-...728(Large).JPG
> I don't have a piece of wire down in the center stub but I don't think
> that matters do you?
>
> How can the center pin be connected to one side of the element
> and the other side of the element be connected to the board? Seems
> like a short to me.
> Thanks guys!
>
> Pete
I've read on some URL that if you don't use wire down the center stub,
it will skew the pattern.
Also what is the spacing between PCB and Biquad, the picture makes it
look to close.
>How can the center pin be connected to one side of the element
> and the other side of the element be connected to the board? Seems
> like a short to me.
At dc it would be a short, at 2.4Ghz there's a lot of inductance and
capacitance.
>What's happening? I thought everything came out great! but the
>BiQuad I just built
>doesn't seem to show any increase in signal strength while using
>Netstumbler!
> I can't see where I went wrong can you?
>http://img.villagephotos.com/p/2003-...728(Large).JPG
>I don't have a piece of wire down in the center stub but I don't think
>that matters do you?
>
>How can the center pin be connected to one side of the element
>and the other side of the element be connected to the board? Seems
>like a short to me.
Yep. Your construction in the photo is totally wrong. It won't work
as shown. The ground ends of the quad elements must be soldered
directly to the ground sleeve of the coax connector, or to short coax
extension. In addition, that looks like a BNC or F connector, which
is a different problem. The center conductor is far too long, the
connector is lossy at 2.4GHz, and it might be a bit flimsy. You'll
find that most construction articles demand an "N" connector or coax
cable extension.
I scribbled a detailed rant on the subject at:
<http://groups.google.com/group/alt.internet.wireless/msg/63d3438fe861bbaa>
It should give a list of biquad construction articles that work, along
with a list of one's similar to yours that will not work.
My favorite are the ones that do not use any connector, such as:
<http://martybugs.net/wireless/biquad/>
Mike,
The spacing is about 15 mm like the article I followed to build it
suggested.
I think I have it working now. Don't think the card was connected!
duh.
But that wire down the center just doesn't seem like it would matter
after
all that center casing is part of the wire if in fact you do solder
one in!
Pete
> > Hey guys,
>
> > What's happening? I thought everything came out great! but the
> > BiQuad I just built
> > doesn't seem to show any increase in signal strength while using
> > Netstumbler!
> > I can't see where I went wrong can you?
> >http://img.villagephotos.com/p/2003-...728(Large).JPG
> > I don't have a piece of wire down in the center stub but I don't think
> > that matters do you?
>
> > How can the center pin be connected to one side of the element
> > and the other side of the element be connected to the board? Seems
> > like a short to me.
> > Thanks guys!
>
> > Pete
>
> I've read on some URL that if you don't use wire down the center stub,
> it will skew the pattern.
> Also what is the spacing between PCB and Biquad, the picture makes it
> look to close.
>
> >How can the center pin be connected to one side of the element
> > and the other side of the element be connected to the board? Seems
> > like a short to me.
>
> At dc it would be a short, at 2.4Ghz there's a lot of inductance and
> capacitance.
>
> Mike- Hide quoted text -
>
> - Show quoted text -
> >What's happening? I thought everything came out great! but the
> >BiQuad I just built
> >doesn't seem to show any increase in signal strength while using
> >Netstumbler!
> > I can't see where I went wrong can you?
> >http://img.villagephotos.com/p/2003-...728(Large).JPG
> >I don't have a piece of wire down in the center stub but I don't think
> >that matters do you?
>
> >How can the center pin be connected to one side of the element
> >and the other side of the element be connected to the board? Seems
> >like a short to me.
>
> Yep. Your construction in the photo is totally wrong. It won't work
> as shown. The ground ends of the quad elements must be soldered
> directly to the ground sleeve of the coax connector, or to short coax
> extension. In addition, that looks like a BNC or F connector, which
> is a different problem. The center conductor is far too long, the
> connector is lossy at 2.4GHz, and it might be a bit flimsy. You'll
> find that most construction articles demand an "N" connector or coax
> cable extension.
>
> I scribbled a detailed rant on the subject at:
> <http://groups.google.com/group/alt.internet.wireless/msg/63d3438fe861...>
> It should give a list of biquad construction articles that work, along
> with a list of one's similar to yours that will not work.
>
> My favorite are the ones that do not use any connector, such as:
> <http://martybugs.net/wireless/biquad/>
>
> --
> Jeff Liebermann je...@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
Let me know what ya think. This is the same one as pictured above,
didn't change a thing.
Pete
>
>
>
> > >What's happening? I thought everything came out great! but the
> > >BiQuad I just built
> > >doesn't seem to show any increase in signal strength while using
> > >Netstumbler!
> > > I can't see where I went wrong can you?
> > >http://img.villagephotos.com/p/2003-...728(Large).JPG
> > >I don't have a piece of wire down in the center stub but I don't think
> > >that matters do you?
>
> > >How can the center pin be connected to one side of the element
> > >and the other side of the element be connected to the board? Seems
> > >like a short to me.
>
> > Yep. Your construction in the photo is totally wrong. It won't work
> > as shown. The ground ends of the quad elements must be soldered
> > directly to the ground sleeve of the coax connector, or to short coax
> > extension. In addition, that looks like a BNC or F connector, which
> > is a different problem. The center conductor is far too long, the
> > connector is lossy at 2.4GHz, and it might be a bit flimsy. You'll
> > find that most construction articles demand an "N" connector or coax
> > cable extension.
>
> > I scribbled a detailed rant on the subject at:
> > <http://groups.google.com/group/alt.internet.wireless/msg/63d3438fe861...>
> > It should give a list of biquad construction articles that work, along
> > with a list of one's similar to yours that will not work.
>
> > My favorite are the ones that do not use any connector, such as:
> > <http://martybugs.net/wireless/biquad/>
>
> > --
> > Jeff Liebermann je...@cruzio.com
> > 150 Felker St #D http://www.LearnByDestroying.com
> > Santa Cruz CA 95060http://802.11junk.com
> > Skype: JeffLiebermann AE6KS 831-336-2558- Hide quoted text -
>
> - Show quoted text -
>On Sep 6, 5:58 pm, Knight <petelar...@comcast.net> wrote:
>> Jeff,
>>
>> It is a "N" connector. A "N" bulkhead connector.
Ok, I couldn't tell the size from the photo.
>Guys, heres a screenshot of what's happening while the quad is
>connected.
>Does it look OK to you? Doesn't look bad to me!
>http://img.villagephotos.com/p/2003-8/361947/biquad.jpg
>
>Let me know what ya think. This is the same one as pictured above,
>didn't change a thing.
Looks like about 8dBi of gain over what you were using as a reference
antenna. That's about what I would expect from a Biquad. I guess
it's working.
A while ago, I got into a debate over the construction of biquads and
how much creativity can be tolerated. So, I ran some models and got a
suprise. See:
A proper biquad:
<http://802.11junk.com/jeffl/antennas/Biquad/>
A creatively built biquad-junk:
<http://802.11junk.com/jeffl/antennas/biquad-junk/>
Despite the miserable 7:1 VSWR mismatch, the junk antenna still
manages to get about 11dBi of gain, the same as the proper biquad. So,
if your radio can handle the crappy VSWR, feel free to throw it
together any way that seem workable.
Jeff,
Earlier you wrote "Your construction in the photo is totally wrong"
I guess it really doesn't matter then does it? Seems to be working
ok!
Can that be? Would it work better the other way?
Pete
> >> It is a "N" connector. A "N" bulkhead connector.
>
> Ok, I couldn't tell the size from the photo.
>
> >Guys, heres a screenshot of what's happening while the quad is
> >connected.
> >Does it look OK to you? Doesn't look bad to me!
> >http://img.villagephotos.com/p/2003-8/361947/biquad.jpg
>
> >Let me know what ya think. This is the same one as pictured above,
> >didn't change a thing.
>
> Looks like about 8dBi of gain over what you were using as a reference
> antenna. That's about what I would expect from a Biquad. I guess
> it's working.
>
> A while ago, I got into a debate over the construction of biquads and
> how much creativity can be tolerated. So, I ran some models and got a
> suprise. See:
>
> A proper biquad:
> <http://802.11junk.com/jeffl/antennas/Biquad/>
>
> A creatively built biquad-junk:
> <http://802.11junk.com/jeffl/antennas/biquad-junk/>
>
> Despite the miserable 7:1 VSWR mismatch, the junk antenna still
> manages to get about 11dBi of gain, the same as the proper biquad. So,
> if your radio can handle the crappy VSWR, feel free to throw it
> together any way that seem workable.
>
> --
> Jeff Liebermann je...@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
>Earlier you wrote "Your construction in the photo is totally wrong"
Yep. It's totally wrong. However, it appears that such creativity
doesn't have as much effect as I original assumed. Look at it this
way: Anything is better than the stock rubber ducky antenna.
> I guess it really doesn't matter then does it? Seems to be working
>ok!
Yep. My simulation of doing it the wrong way shows that it works well
enough. You decide if it's good enough for your purposes and if it's
worth your time doing it the right way.
>Can that be? Would it work better the other way?
Yes. The rather high VSWR (impedance mismatch) will certainly have an
effect on gain. If I plug the estimated antenna impedance from:
<http://802.11junk.com/jeffl/antennas/biquad-junk/slides/main.html>
as 58.7 -j106 ohms into a mismatch calculator at:
<http://chemandy.com/calculators/return-loss-and-mismatch-calculator.htm>
I get about 3dB of loss with this mismatch. In theory, you should be
able to recover most of that by proper construction.
On Sep 6, 2:53 pm, Jeff Liebermann <je...@cruzio.com> wrote:
> Knight <petelar...@comcast.net> hath wroth:
>
> >What's happening? I thought everything came out great! but the
> >BiQuad I just built
> >doesn't seem to show any increase in signal strength while using
> >Netstumbler!
> > I can't see where I went wrong can you?
> >http://img.villagephotos.com/p/2003-...728(Large).JPG
> >I don't have a piece of wire down in the center stub but I don't think
> >that matters do you?
>
> >How can the center pin be connected to one side of the element
> >and the other side of the element be connected to the board? Seems
> >like a short to me.
>
> Yep. Your construction in the photo is totally wrong. It won't work
> as shown. The ground ends of the quad elements must be soldered
> directly to the ground sleeve of the coax connector, or to short coax
> extension. In addition, that looks like a BNC or F connector, which
> is a different problem. The center conductor is far too long, the
> connector is lossy at 2.4GHz, and it might be a bit flimsy. You'll
> find that most construction articles demand an "N" connector or coax
> cable extension.
>
> I scribbled a detailed rant on the subject at:
> <http://groups.google.com/group/alt.internet.wireless/msg/63d3438fe861...>
> It should give a list of biquad construction articles that work, along
> with a list of one's similar to yours that will not work.
>
> My favorite are the ones that do not use any connector, such as:
> <http://martybugs.net/wireless/biquad/>
>
> --
> Jeff Liebermann je...@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558
My Biquad doesn't work 
Linear Mode
