Prev: Any experience with RadioLab GS2000 wireless bridge?
Next: Router problems.
From: jimmie68 on 29 Jul 2008 16:52
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

From: Jeff Liebermann on 29 Jul 2008 23:47
On Tue, 29 Jul 2008 13:52:22 -0700 (PDT), jimmie68(a)gmail.com wrote:

>In WiFi is there any standard convention for the polarity of a helical
>antenna.

The do it thyself defacto standard was established by the AO40,
Inmarsat, and various WX satellites. All are right hand circular
polarization for the ground station.

Be careful if you build a helical feed for a dish or other reflector
antenna. The reflection changes the sense, so a dish would need a
left hand circular polarized feed.

>I am building a 40 turn unit and wanted to know whether I
>should build it right or left handed.

Right hand.

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

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl(a)comix.santa-cruz.ca.us
# http://802.11junk.com jeffl(a)cruzio.com
# http://www.LearnByDestroying.com AE6KS
From: miso on 29 Jul 2008 23:47
On Jul 29, 1:52 pm, jimmi...(a)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.
From: jimmie68 on 30 Jul 2008 16:57
On Jul 29, 11:47 pm, m...(a)sushi.com wrote:
> On Jul 29, 1:52 pm, jimmi...(a)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
From: miso on 31 Jul 2008 01:12
On Jul 30, 1:57 pm, jimmi...(a)gmail.com wrote:
> On Jul 29, 11:47 pm, m...(a)sushi.com wrote:
>
> > On Jul 29, 1:52 pm, jimmi...(a)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.



 |  Next  |  Last
Pages: 1 2 3 4 5
Prev: Any experience with RadioLab GS2000 wireless bridge?
Next: Router problems.