Helix antenna

In WiFi is there any standard convention for the polarity of a helical
antenna. I am building a 40 turn unit and wanted to know whether I
should build it right or left handed.

Yes I know this will only matter when trying to connect with other
systems that use circular polarity.

Jimmie

On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
> In WiFi is there any standard convention for the polarity of a helical
> antenna. I am building a 40 turn unit and wanted to know whether I
> should build it right or left handed.
>
> Yes I know this will only matter when trying to connect with other
> systems that use circular polarity.
>
> Jimmie

Please post how it works out. Also, have you considered building a 4
10 turn helix (heli?) and run in parallel. That gets around the
matching issue.

On Jul 29, 11:47*pm, m...@sushi.com wrote:
> On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > In WiFi is there any standard convention for the polarity of a helical
> > antenna. I am building a 40 turn unit and wanted to know whether I
> > should build it right or left handed.
>
> > Yes I know this will only matter when trying to connect with other
> > systems that use circular polarity.
>
> > Jimmie
>
> Please post how it works out. Also, have you considered building a 4
> 10 turn helix (heli?) and run in parallel. That gets around the
> matching issue.

Yes, I thought about that but I have plans for the 40 turn unit
including the matching device. Also I have access to a Network
Analyzer and S pararamter test set for tuning it up. I think building
the matching network may be easier than build a phasing harness for 4
Helix antennas. However I have never done this before so plans may
change. Who knows, if things work out OK I may build a 4 X 40 turn
device.

Jimmie

On Jul 30, 1:57*pm, jimmi...@gmail.com wrote:
> On Jul 29, 11:47*pm, m...@sushi.com wrote:
>
> > On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > > In WiFi is there any standard convention for the polarity of a helical
> > > antenna. I am building a 40 turn unit and wanted to know whether I
> > > should build it right or left handed.
>
> > > Yes I know this will only matter when trying to connect with other
> > > systems that use circular polarity.
>
> > > Jimmie
>
> > Please post how it works out. Also, have you considered building a 4
> > 10 turn helix (heli?) and run in parallel. That gets around the
> > matching issue.
>
> Yes, I thought about that but I have plans for the 40 turn unit
> including the matching device. Also I have access to a Network
> Analyzer and S pararamter test set for tuning it up. I think building
> the matching network may be easier than build a phasing harness for 4
> Helix antennas. However I have never done this before so plans may
> change. Who knows, if things work out OK I may build a 4 X 40 turn
> device.
>
> Jimmie

My guess is paralleling the 4 helix antennas would have a broader
bandwidth than the impedance matched solution. Broadband is good in
the sense that it allows for more error in the construction.

On Jul 31, 1:12*am, m...@sushi.com wrote:
> On Jul 30, 1:57*pm, jimmi...@gmail.com wrote:
>
>
>
>
>
> > On Jul 29, 11:47*pm, m...@sushi.com wrote:
>
> > > On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > > > In WiFi is there any standard convention for the polarity of a helical
> > > > antenna. I am building a 40 turn unit and wanted to know whether I
> > > > should build it right or left handed.
>
> > > > Yes I know this will only matter when trying to connect with other
> > > > systems that use circular polarity.
>
> > > > Jimmie
>
> > > Please post how it works out. Also, have you considered building a 4
> > > 10 turn helix (heli?) and run in parallel. That gets around the
> > > matching issue.
>
> > Yes, I thought about that but I have plans for the 40 turn unit
> > including the matching device. Also I have access to a Network
> > Analyzer and S pararamter test set for tuning it up. I think building
> > the matching network may be easier than build a phasing harness for 4
> > Helix antennas. However I have never done this before so plans may
> > change. Who knows, if things work out OK I may build a 4 X 40 turn
> > device.
>
> > Jimmie
>
> My guess is paralleling the 4 helix antennas would have a broader
> bandwidth than the impedance matched solution. Broadband is good in
> the sense that it allows for more error in the construction.- Hide quotedtext -
>
> - Show quoted text -

Usually paralelling(stacking) antennas means a narrower bandwidth.
This statement assumes all the stacked antennas are identical.

Jimmie

On Aug 1, 4:33*pm, jimmi...@gmail.com wrote:
> On Jul 31, 1:12*am, m...@sushi.com wrote:
>
>
>
>
>
> > On Jul 30, 1:57*pm, jimmi...@gmail.com wrote:
>
> > > On Jul 29, 11:47*pm, m...@sushi.com wrote:
>
> > > > On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > > > > In WiFi is there any standard convention for the polarity of a helical
> > > > > antenna. I am building a 40 turn unit and wanted to know whether I
> > > > > should build it right or left handed.
>
> > > > > Yes I know this will only matter when trying to connect with other
> > > > > systems that use circular polarity.
>
> > > > > Jimmie
>
> > > > Please post how it works out. Also, have you considered building a 4
> > > > 10 turn helix (heli?) and run in parallel. That gets around the
> > > > matching issue.
>
> > > Yes, I thought about that but I have plans for the 40 turn unit
> > > including the matching device. Also I have access to a Network
> > > Analyzer and S pararamter test set for tuning it up. I think building
> > > the matching network may be easier than build a phasing harness for 4
> > > Helix antennas. However I have never done this before so plans may
> > > change. Who knows, if things work out OK I may build a 4 X 40 turn
> > > device.
>
> > > Jimmie
>
> > My guess is paralleling the 4 helix antennas would have a broader
> > bandwidth than the impedance matched solution. Broadband is good in
> > the sense that it allows for more error in the construction.- Hide quoted text -
>
> > - Show quoted text -
>
> Usually paralelling(stacking) antennas means a narrower bandwidth.
> This statement assumes all the stacked antennas are identical.
>
> Jimmie- Hide quoted text -
>
> - Show quoted text -

This should be of interest to anyo one wanting to build a helix
antena.

http://www.qsl.net/ve3cvg/antennas/2400/

Jimmie

On Aug 1, 1:33*pm, jimmi...@gmail.com wrote:
> On Jul 31, 1:12*am, m...@sushi.com wrote:
>
>
>
> > On Jul 30, 1:57*pm, jimmi...@gmail.com wrote:
>
> > > On Jul 29, 11:47*pm, m...@sushi.com wrote:
>
> > > > On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > > > > In WiFi is there any standard convention for the polarity of a helical
> > > > > antenna. I am building a 40 turn unit and wanted to know whether I
> > > > > should build it right or left handed.
>
> > > > > Yes I know this will only matter when trying to connect with other
> > > > > systems that use circular polarity.
>
> > > > > Jimmie
>
> > > > Please post how it works out. Also, have you considered building a 4
> > > > 10 turn helix (heli?) and run in parallel. That gets around the
> > > > matching issue.
>
> > > Yes, I thought about that but I have plans for the 40 turn unit
> > > including the matching device. Also I have access to a Network
> > > Analyzer and S pararamter test set for tuning it up. I think building
> > > the matching network may be easier than build a phasing harness for 4
> > > Helix antennas. However I have never done this before so plans may
> > > change. Who knows, if things work out OK I may build a 4 X 40 turn
> > > device.
>
> > > Jimmie
>
> > My guess is paralleling the 4 helix antennas would have a broader
> > bandwidth than the impedance matched solution. Broadband is good in
> > the sense that it allows for more error in the construction.- Hide quoted text -
>
> > - Show quoted text -
>
> Usually paralelling(stacking) antennas means a narrower bandwidth.
> This statement assumes all the stacked antennas are identical.
>
> Jimmie

I see no reason for stacked antennas to have a narrower bandwidth. Can
you elaborate?

On Aug 1, 5:09*pm, jimmi...@gmail.com wrote:
> On Aug 1, 4:33*pm, jimmi...@gmail.com wrote:
>
>
>
> > On Jul 31, 1:12*am, m...@sushi.com wrote:
>
> > > On Jul 30, 1:57*pm, jimmi...@gmail.com wrote:
>
> > > > On Jul 29, 11:47*pm, m...@sushi.com wrote:
>
> > > > > On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > > > > > In WiFi is there any standard convention for the polarity of a helical
> > > > > > antenna. I am building a 40 turn unit and wanted to know whether I
> > > > > > should build it right or left handed.
>
> > > > > > Yes I know this will only matter when trying to connect with other
> > > > > > systems that use circular polarity.
>
> > > > > > Jimmie
>
> > > > > Please post how it works out. Also, have you considered building a 4
> > > > > 10 turn helix (heli?) and run in parallel. That gets around the
> > > > > matching issue.
>
> > > > Yes, I thought about that but I have plans for the 40 turn unit
> > > > including the matching device. Also I have access to a Network
> > > > Analyzer and S pararamter test set for tuning it up. I think building
> > > > the matching network may be easier than build a phasing harness for4
> > > > Helix antennas. However I have never done this before so plans may
> > > > change. Who knows, if things work out OK I may build a 4 X 40 turn
> > > > device.
>
> > > > Jimmie
>
> > > My guess is paralleling the 4 helix antennas would have a broader
> > > bandwidth than the impedance matched solution. Broadband is good in
> > > the sense that it allows for more error in the construction.- Hide quoted text -
>
> > > - Show quoted text -
>
> > Usually paralelling(stacking) antennas means a narrower bandwidth.
> > This statement assumes all the stacked antennas are identical.
>
> > Jimmie- Hide quoted text -
>
> > - Show quoted text -
>
> This should be of interest to anyo one wanting to build a helix
> antena.
>
> http://www.qsl.net/ve3cvg/antennas/2400/
>
> Jimmie

When I build antennas, I try to use all copper if I can. Otherwise,
you get a battery connecting Al to copper. I'm not sure about
connecting copper to galvanized. I've built a few log periodics (VHF/
UHF) and used that gunk (OK, not a technical term) used with Al
wiring. Still, it deteriorates with time. Consider using copper wire.

Have you considered the biquad? Unless you have circular polarization
on both ends, you will lose 3db when interfacing with linear polarized
antennas, so 16db becomes 13db, which is close to the biquad.

I guess a long helix would be better for snooping purposes since not
everyone is vertically polarized.

On Aug 2, 8:58*am, Jeff Liebermann <je...@cruzio.com> wrote:
> On Fri, 1 Aug 2008 23:18:03 -0700 (PDT), m...@sushi.com wrote:
> >On Aug 1, 1:33*pm, jimmi...@gmail.com wrote:
> >> Usually paralelling(stacking) antennas means a narrower bandwidth.
> >> This statement assumes all the stacked antennas are identical.
> >> Jimmie
> >I see no reason for stacked antennas to have a narrower bandwidth. Can
> >you elaborate?
>
> If your definition of bandwidth is the frequency between the -3dB
> points, stacking two isolated resonant antennas together results in
> exactly the same bandwidth as one antenna. *An easier way to see this
> is if the two antennas were simple parallel tuned circuits acting as a
> bandpass filter. *If you connect them together, using some means of
> coupling that is critically coupled (i.e. maximum power tranfer), the
> resultant circuit has exactly the same bandwidth. *If you plot it on a
> piece of graph paper, you could stack a dozen critically coupled tuned
> circuits together and get exactly the same -3dB bandwidth. *Obviously
> the skirt factor and bandwidth at other refrence points will be
> narrower as you add sections.
>
> Of course, such things fall apart when dealing with real world devices
> and antennas. *Two stacked antennas will couple to each other, causing
> difficulties with such simplistic explanations. *The traditional 2x2
> array of helixes heavily couple to each other, especially since
> they're the same sense. *Anyway, the only way to get it right is to
> fire up your favorite NEC antenna modeling program, which takes such
> things into consideration. *4NEC2 includes a helix generator.
>
> Specifically for a helix, the approximate -3dB bandwidth for a single
> helix is roughly equal to the center frequency. *In other words, if
> you cut a helix for 2.4GHz, it will be usable from 1.2 to 3.6Ghz.
> Stacking 4 of these together will theoretically not reduce this
> bandwidth, but in reality, will reduce it somewhat. *I don't think
> operation in an 83.5MHz band is going to be affected with an antenna
> with a 1 or 2Ghz bandwidth.
>
> --
> 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

How about the impedance matching scheme? That must narrow the
bandwidth. Also your comments on mixing Al and Cu?

On Aug 2, 2:18*am, m...@sushi.com wrote:
> On Aug 1, 1:33*pm, jimmi...@gmail.com wrote:
>
>
>
>
>
> > On Jul 31, 1:12*am, m...@sushi.com wrote:
>
> > > On Jul 30, 1:57*pm, jimmi...@gmail.com wrote:
>
> > > > On Jul 29, 11:47*pm, m...@sushi.com wrote:
>
> > > > > On Jul 29, 1:52*pm, jimmi...@gmail.com wrote:
>
> > > > > > In WiFi is there any standard convention for the polarity of a helical
> > > > > > antenna. I am building a 40 turn unit and wanted to know whether I
> > > > > > should build it right or left handed.
>
> > > > > > Yes I know this will only matter when trying to connect with other
> > > > > > systems that use circular polarity.
>
> > > > > > Jimmie
>
> > > > > Please post how it works out. Also, have you considered building a 4
> > > > > 10 turn helix (heli?) and run in parallel. That gets around the
> > > > > matching issue.
>
> > > > Yes, I thought about that but I have plans for the 40 turn unit
> > > > including the matching device. Also I have access to a Network
> > > > Analyzer and S pararamter test set for tuning it up. I think building
> > > > the matching network may be easier than build a phasing harness for4
> > > > Helix antennas. However I have never done this before so plans may
> > > > change. Who knows, if things work out OK I may build a 4 X 40 turn
> > > > device.
>
> > > > Jimmie
>
> > > My guess is paralleling the 4 helix antennas would have a broader
> > > bandwidth than the impedance matched solution. Broadband is good in
> > > the sense that it allows for more error in the construction.- Hide quoted text -
>
> > > - Show quoted text -
>
> > Usually paralelling(stacking) antennas means a narrower bandwidth.
> > This statement assumes all the stacked antennas are identical.
>
> > Jimmie
>
> I see no reason for stacked antennas to have a narrower bandwidth. Can
> you elaborate?- Hide quoted text -
>
> - Show quoted text -

Sorry I was thinking of bandwidth in terms of frequency versus VSWR.
This is usally the limiting factor as gain bandwidth is almost always
much broader
than VSWR bandwidth.
As of yet I dont know whether this will be a serious consequence or
not concerning the helix antenna.

My plan is to build the antenna and tune it for greatest field
strength

A few years ago I stacked 2 2 meter 6 element quad antennas. I had
plans to stack 4 but didnt do it because
of the VSWR excursion from one end of the band to the other.
My solidstate amp was not fond of the 2 to 1 VSWR near the band edges.

In this situation the VSWR bandwidth of 2 antennas was less than 1
antenna and with 4 antennas it was even less.
I am sure the array would have still exhibited considerable gain if I
had a way to readily correct for the impedance changes seen by my
amplifier.

Jimmie